Device and method for receipt and synchronization at mobile platform in direct digital satellite broadcast system

FIELD: engineering of devices and methods for receipt and synchronization in direct digital satellite broadcast system.

SUBSTANCE: satellite system uses modulation with temporal signals separation and single-frequency network of ground-based re-emitting stations, each of which introduces a delay to ground signal. Delay allows to provide for coincidence of time of receipt of early modulated signal in the center of ground broadcasting zone with time of receipt of appropriate late modulated signal, thus improving switching between ground and satellite signals in receiver. Delay also compensates processing delay, occurring during conversion of satellite modulated stream under direct visibility conditions to multi-frequency modulated stream for transmission of satellite modulated stream under direct visibility conditions to user receivers. Delay is also adjusted in accordance to distance difference between each ground-based re-emitting station and satellite and between each station and center of ground-based broadcasting zone. Adjustment as described above optimizes receipt of temporal signals separation modulated and multi-frequency modulated signals by means of synchronization in the center of single-frequency system of phase of multi-frequency modulated signals, re-emitted from re-emitting stations of single-frequency system.

EFFECT: increased quality of radio-signal receipt.

8 cl, 12 dwg

 

The technical field

The present invention relates to a method and apparatus for receiving and synchronization in the system of direct digital satellite broadcasting, which uses the reception only from satellite within line-of-sight (LPV) or the reception conditions LPV reradiation on Earth.

Background of the invention

A significant impact on the operation of the receivers in existing systems, which are terrestrial and/or satellite digital autoradiography (ZARA (DARS)), has a block, shadowing and multipath, resulting in severe deterioration of signal quality, such as a freeze signal and intersymbol interference (ISI (ISI)caused by multipath propagation. Such an influence on the communication channels at the receiver may vary depending on location and frequency, particularly in urban areas or in certain geographic areas with high gradients of elevation, where the blocking line-of-sight signal from the satellites is predominant.

Blocking signals in portable and mobile receivers may be due to the appearance of the physical obstacles between the transmitter and receiver. Welcome to mobile receivers may be, for example, is difficult physically, when they LW who move through tunnels or moved close to buildings or trees, which obstruct the reception of the satellite signal in the zone of direct visibility. Breaks in service delivery can also occur at much higher tolerance level of the reception signal due to reflections when multipath propagation of the desired signal.

Located directly below the satellite (hereinafter referred to as the sub-satellite point)essentially contains the highest elevation angles LPW, while at locations away from the sub-satellite point, essentially, the elevation angles LPV decrease and, accordingly, increases the likelihood of blocking and shading. Designated outside areas near to the ground point, effectively provide a non-blocking receive LPV. The need for ground reemission potentially blocked signals LPV will be minimal. However, when the elevation angle LPV towards the satellite will be less than approximately 85 degrees, blocking high buildings or geological elevations (i.e. height of about 30 metres) becomes essential. This requires terrestrial re-radiation to fill the gaps signal and provide satisfactory reception area mobile radios, as well as stationary and portable radios. In areas where the height of the building is or geological barriers relatively small (i.e. less than 10 meters), blocking is negligible, unless the distance from the ground point does not exceed 1400 km, when the lower elevation LPV comes to less than 75 degrees. For a distance of 6300 km from the sub-satellite point, the elevation drops to below 25°and this greatly increases the need to use ground reemission of the satellite signal.

Thus, in areas at medium and high latitudes in the coverage area of one or more broadcasting satellites you want to use terrestrial re-radiation to ensure the quality of radio reception. For successful reception by mobile radio direct satellite signals LPV and when they are combined with the same signals re-radiated by the Earth, is required to provide the receiving location close relative synchronizing and combining the direct satellite signals LPV with signals, repeated in the terrestrial network. In addition, in the location you want to keep close synchronization between the signals re-radiated by different ground stations.

Brief description:

The above drawbacks can be eliminated, and allows the implementation of many advantages by combining signals from the time the military division, transmitted directly from the satellite in terms LPV, or signals with temporal and spatial separation of the transmitted directly from the satellite in terms LPV, with signals re-radiated by the land division, which are generated based on the received at ground station signals transmitted directly from the satellite in terms LPV that pereklokayutsia as terrestrial radio waves in and around the city. Due to this, the signals directly received from the satellite in terms LPV, time division, or temporal and spatial separation, can be taken together with the terrestrial signals are then re-emitted, which are appropriately delayed signal from the satellite directly accept the conditions LPV, to receive the satellite/ground separation. With this you can provide the movement of the mobile receiver in areas where the predominant direct reception of satellite signals LPV or in the city and in its surrounding areas, where mainly dominated by terrestrial pereizlucheniya signals, or to provide a transition between the two types of areas without interrupting the reception. To ensure sufficient quality continuity of the time of arrival of the satellite signals in line-of-sight and pereizluchennykh athamneh signals synchronized to within 10 milliseconds.

In accordance with one aspect of the present invention, the centers of broadcast zones defined for groups of ground stations of reemission. The signals emitted by each of a number of ground stations reemission adjusted so as to compensate the difference of the distances between the respective ground stations and reemission approximate center of the zone broadcast.

In accordance with another aspect of the present invention, the satellite signals re-radiated from the ground station, adjust to compensate for the time difference of arrival earlier signal from the satellite and the signal ground stations are then re-emitted.

In accordance with another aspect of the present invention, the signals radiated from ground stations of reemission adjusted so as to compensate for the delay that occurs when generating signal ground station using the satellite signal at the ground station then re-emitted.

In accordance with another aspect of the present invention, the symbols in the stream of multiplexed data with a temporal separation of arriving at the ground station re-emission, combined with multi-frequency modulated symbols in the multi-frequency modulated signal, the multiplexed signal from the time division.

ACC is accordance with another alternative embodiment of the present invention, at least one approximate center of the zone broadcast is determined for a selected number of said geographically separated ground stations of reemission. Determine corresponding to the difference of the distances between each of the selected number of ground stations and reemission approximate center of the zone broadcast. Then make the correction terrestrial signal to compensate for the different time of arrival of the terrestrial signal transmitted by the selected number of ground stations are then re-emitted, the user terminal because of a difference of distances between the corresponding selected number of ground stations and reemission approximate center of the zone broadcast.

In accordance with another alternative embodiment of the present invention, a device for use in ground stations reemission receives multiplexed data stream with time division, containing symbols, and each of these symbols corresponds to the selected number of bits in the data stream. A processing unit connected to the receiving device determines the location of the preamble of the main frame in the data stream. The processing unit converts the characters in the stream are multiplexed data with temporal separation (data, m (TDM)into the respective subcarriers, multiplex the new orthogonal frequency division (MODC (OFDM)) to generate a multiplexed signal time division/frequency modulated signal (MBP-MISI (MSM)), which contains mnogochastotnom-modulated symbols, each of which has a selected number of sub-carriers, which transport time-serial characters signal the ISI. The processing device sometimes referred to as the transducer signal compaction MBP MFM. The processing device uses the preamble of the main frame MBP or, alternatively, the unique code that is distributed throughout the frame MBP for synchronization symbols in the data stream with a corresponding one of the subcarriers in the respective mnogochastotnom-modulated symbols.

In accordance with another alternative embodiment of the present invention, each transmitter of reemission transmits a signal MVP-MISI high power distribution terrestrial radio waves in the city or from the top of the hill or along the road through antennas mounted on towers at sufficient height to ensure that the distance from 1 to 20 km in accordance with the necessity.

Brief description of drawings

The various aspects, advantages and new features of the present invention will be better understood when reading the following detailed description in conjunction with the attached drawings, on which:

Figa and 1b depict the channels using one satellite for transmitting signals with time division, done is nnow in accordance with one alternative embodiment of the present invention;

Figure 2 - broadcasting system, which uses two satellites to transmit signals with a temporal and spatial separation in accordance with one alternative embodiment of the present invention;

Figure 3 is a graph illustrating the duration of the fade, which determines the amount of delay to optimize reception time division;

4 is a terrestrial single frequency network MBP-MISI (SFN), made in accordance with one alternative embodiment of the present invention,

5 is a synchronization character MBP with subcarriers MISI in accordance with one alternative embodiment of the present invention,

6 is a modulation symbol MBP subcarriers MISI in accordance with one alternative embodiment of the present invention;

7 - calculation of the difference of the delay between the satellite and the ground station then re-emitted in the conditions LPV, as well as the difference of delays between ground stations and reemission center broadcast single frequency network, in accordance with one alternative embodiment of the present invention;

Fig - convert horizontal distances in the distance LPW for use in the synchronization frame MBP-MISI depicted in Fig.7;

Fig.9 - division frame MBP frames MISI, in accordance with one alternative embodiment of the present invention;

1 shows the alignment of the ICM-MISI, emitted by many stations in a single frequency network having a selected diameter occupancy, in accordance with one alternative embodiment of the present invention;

Figure 11 shows the maximum diameter of the distribution of terrestrial stations are then re-emitted in a single frequency network, in accordance with one alternative embodiment of the present invention.

A detailed description of the preferred embodiment variants of the invention

In satellite data transmission systems can be used time division signals, or a combination of temporal and spatial separation of the signals to reduce the undesirable effects of block, shadowing, fading in multipath propagation. For example, the data transfer system with time division allows you to pass early and late signals from the satellite (i.e. one signal is transmitted with a delay on the selected time interval relative to another signal) in one straight flow of data in terms of LPV. Alternatively, in the data transmission system with time multiplexing is the transmission of early and late signals respectively to two direct data streams LPV. The duration of the time interval between the early and late signals is determined based on the duration of interruption of service due to the block that you want to resolve. The required delay is determined on the basis of experimental data. In addition, two direct data flow LPV can be transmitted respectively through two spaced companion for the implementation of spatial separation and temporal separation. In both cases the channel without delay receive delay in the terrestrial transmitter reemission and/or in the receiver so that the early and late channels can be constructively combined.

Both of the above variants of the embodiment of the direct satellite explode in terms LPV can be combined with a network of ground stations reemission to prevent blocking by buildings, bridges and tunnels, which manifests itself both in towns and in large cities, where direct reception LPV from satellites are not always available. The terrestrial network may contain from one to an arbitrary number of stations in accordance with the need to ensure the required zone broadcast. To use ground reemission direct satellite signals in the present invention is provided for converting a signal of the ICM satellite signal with frequency modulation, which, essentially, is a robust and reliable when used in environments where multipath spread is their radio waves in the propagation of terrestrial radio waves in the Central business districts and major cities and suburban areas. The present invention uses means for synchronizing and combining the direct signals LPV satellite with a repetition of the satellite signal through a terrestrial network reemission to ensure continuous continuous when moving through areas in which provided coverage only satellite in the areas of broadcast zones with the urban landscape, as well as during the transition between the two types of regions.

For generating a ground signal stream of data characters MBP, received, converted into a signal with frequency modulation. This is done by converting OBPF (IFFT) (inverse fast Fourier transform)in which the symbols of the data stream MBR synchronously and accurately are assigned to individual subcarriers MBP-MISI is the same for all ground stations are then re-emitted terrestrial SFN. The signal MVP-MISI known as the signal resistant to interference multipath propagation of radio waves, and provides reliable reception in areas where reception is within line of sight substantially blocked.

1. Receiving at the mobile receiver from the satellites within line-of-sight.

The following describes the signal transmission using electromagnetic waves directly between the satellite transmitters and mobile receivers. As stated above, blokirovki the signal at the receiver may occur because of the emergence of physical obstacles between the transmitter and receiver. In addition, interruptions in the provision of services may be due to attenuation, the failure signal and the disturbance of the phase of the carrier. Mobile receivers, for example, can be blocked by physical obstacles, when they move in tunnels or near buildings or trees that pose a hindrance to the reception of a signal within line-of-sight (LPV). Interruptions in the provision of services may occur, on the other hand, due to the failure signal attenuation or violations of the phase of the carrier, at a sufficiently high level of reflections when multipath propagation of the signal is compared with the desired signal.

In satellite data transmission systems can be used only a temporary separation of signals, only the spatial separation of signals or the temporal and spatial separation of the signals together, to reduce the effects of unwanted effects blocking communication within line of sight, shadowing and fading due to multipath propagation. For example, as shown in figa, the system 10 satellite data using only a temporary separation may be transferred early and late versions of the same signal in the same live stream 12 of data in terms of LPV via satellite 14 (i.e. late signal is an exact copy of Runnig the signal, but delayed by a selected time interval). Alternatively, as shown in fig.1b, the system 10 data, which uses only a temporary separation, via satellite 14 may be transmitted to one thread 18 of the data in terms LPV, in which only sent early signals, and other data flow LPV, which is transmitted only late signals.

Satellite data transmission system, which combines spatial and temporal partitioning shown in figure 2. Two direct stream 16 and 18 of the data in terms LPV can be transmitted respectively via two satellites 14 and 20, which are spaced by a distance sufficient for the implementation of spatial separation. Temporal partitioning is carried out either by passing the mixed signal of the early and late related signals in each data stream, or by transferring all early signals in one data stream and all subsequent signals in a different data stream.

For any of the system configurations on figa, fig.1b or 2 signal without delay (i.e., early satellite signal) gets the delay in the receiver 22 so that it can be synchronously combined with late concomitant signal in one signal. The method of maximum likelihood for the implementation of such a combination is described below.

The signal PR is dostavlennya on figa, fig.1b and 2, preferably, are signals of broadcasting channels (VC), which are given to selected broadcast program. Individual broadcast programs are assigned to the broadcast channels. One broadcast channel of the broadcast program without delay (and hence is called early). On the second channel transmits the same broadcast program, except that it takes place with a delay (and hence is called later). These early and late broadcast channels can be viewed as transmitting auxiliary signals, one channel is transmitted on one carrier, and another channel at the same time is transmitted to the opposite transport carrier.

For the satellite signal, indicated at figa position 12, the receiver 22 in the system 10, which uses only one straight flow conditions LPV from one satellite 14 to provide temporary separation takes only one multiplexed carrier time division (ISI) for the realization of such a mode of operation. To this end, the receiver uses a single RF unit, which of the carrier MBP. In this situation, for each mobile broadcast program you are passing two direct broadcast channels direct mobile reception conditions LPV water and the same thread MBP. The characters in each broadcast channel multiplexed 33 time division within the personnel carrier MBP together with other broadcasting channels. One broadcast channel is an early signal, and another broadcast channel is a late signal. This process provides a temporary separation in the receiver 22, which improves the possibility of continuous permanent admission in cases of a dynamic block that may occur in the vehicle moving, for example, on the road.

As shown in fig.1b, with the help of signals 16 and 18 satellites in the system 10 are formed two threads 27 of the ICM and the demultiplexing and decoding of the respective broadcast channels of these streams MBP, and the receiver 22 includes equipment for receiving and processing two satellite carrying the MBP. To this end, the receiver 22 includes a radio frequency (RF) unit, which allows you to take two satellite carrying the MBP. You can use one radio frequency unit having sufficient bandwidth for reception of two radio-frequency carrying ICBMs. This design is particularly preferable when the spectra of carrying ICBMs are continuously compared to each other. However, in some cases, two bearing cannot be located not in posredstvennoj proximity and must be separated by spectrum so that it is impossible to use a single radio block. In this situation, for receiving two carrier frequencies in the receiver properly placed and installed two separate and independent of the radio frequency unit. Layout with one RF unit will be referred to as single-channel satellite receiver, and layout with two RF sections will be referred to as dual satellite receiver.

The time interval between the early and late signals is determined by the length of the interruption in the provision of services, which should be avoided. The duration of the interruption in the provision of services is determined by the distribution and size of the blocking interference. In urban blocks are often buildings of various heights, located at different distances from the streets. In the agricultural districts, blocks, most likely, represent the trees surrounding and overhanging the highway or on a dirt road. In both cases, you should also consider the bridges and tunnels. Documented research that provides a basis for an appropriate choice of the delay amount for cities and highways described below with reference to figure 3. The time delay between the early and late signals, preferably, is a systems is the first parameter, which is a function of the physical distribution of the blocking objects in terms LPV and vehicle speed. This value delays for vehicles traveling along the normal of rural roads with typical values of speed (from 30 to 60 miles per hour (lasts for 48-96 km/h)) is chosen long enough to overlap the distribution of the blocking objects. The delay is chosen such that it was preferably sufficiently long to resolve, preferably from 97% to 99% of the blocking objects, but not so long that significantly complicate the design of the receiver (for example, so that the complexity and/or cost of the receiver would be commercially unacceptable). As an example, consider the duration of this block for a vehicle passing under the bridge width of 50 feet (15 m) at a speed of 30 mph (48 km/h). Conditions LPV from the satellite is blocked at 1,136 seconds, and the delay of the late signal should be at least equal to this value.

Measurement of blocking conditions were conducted for rural roads and are described in publications of authors Lutz and others (Lutz et al.), Land mobile transmission of data from the satellite - model of the channel, modulation and error control" ("Land Mobile Satellite Communication Channel Model, Modulation and Error Control), Proceedings ICDSC-7, the international conference is ncia digital satellite data 12-16 may 1986. Using data from this publication, was built by the graph of the fraction of the observed block from the available depth boundaries fading for mixed obstacles, such as bridges, structures installed along the roads, buildings and trees. These data, presented in figure 3, show that the depth of the boundary fading 12 dB delay time is in the range from 2 to 8 seconds. Depth boundaries fade margin is the difference between the level of the signal received from the satellite, and the unacceptable level of signal reception. For example, if the signal from the satellite will be strong enough to ensure border fading 12 dB in figure 3 you can see that the maximum reception time division is provided with a delay of 6 to 8 seconds.

Another means of improving reception of satellite signals in a mobile situation is the device alternations. Such a device alternation is designed for emission control in individual bits or the error symbol, which can result from accidentally changing the transmission conditions, the amplitude of the fading caused by multipath propagation, and/or blocking for quite a long period to compensate deliberate actions to correct errors in the case of an estate the purpose of the coding device 30, a forward error correction and supplementing their decoders 28 maximum likelihood. Such interleaving is performed by reordering the temporal sequence of bits or characters of the message in the transmitter for random and uniform distribution on the time window equal to the length alternations. The result is that adjacent bits or symbols of the incoming message are separated as far as possible from each other. If intermittent bits or symbols of the message burst errors during transmission to the receiver, the effect of complementary facing devices alternation in the receiver to restore the original order will cause dispersion of bits or symbols with error across the entire time window devices alternation, so that they will appear in the decoder for forward error correction (PIO) in the form of randomly distributed short emission of bits with errors. Decoder (PIO (FEC)) (forward error correction) makes such errors. It is assumed that the use of such devices alternation in combination with coding devices and decoders PIO is part of the processing used for end-to-end transmission of messages or signals sent by the system being described. Device interleave, essentially, installed after the encoding device 30 PIO in the transmitter 24 and before the decoders 28 PIO in the receiver 22. The duration of the time window such the disorders can be chosen in the range from one to several frames ICBMs.

Device alternation can also be used in the form of cross-device alternations. Cross-device interleave includes a pair of devices alternation that work with a pair of bit streams messages so that each device interleave works with approximately half of the bits of each message flow. The bits of the message flow is divided and ordered pseudo-random and evenly. For example, input devices alternation comes a pair of streams of messages. Cross-device alternation affects the bits so that the generated two output transversely of intermittent flow. The device interleave divides the bits of each input message pseudo law, giving them in the form of two output cross-intermittent streams. While the bits are separated from each other as far as possible in each pair of cross-intermittent streams. Each of the cross-intermittent flow transports half the contents of each input message. Each stream is transmitted in various ways. When used in combination with the original convolutional encoder, the output of which is divided into two streams of messages, to generate the input signals for perekrestnogo alternation, and a Viterbi decoder (for example, using a convolutional decoder, suitable what about the original coder), the bit stream of the message, which was an input stream for the source of the convolutional encoder, re-encoded by the maximum likelihood method on the output of the Viterbi decoder. This process eliminates the error bits in the transmission occurring in the form of bursts caused by blockage, shadowing and fading in the multipath propagation that can occur when using paths direct reception in the line of sight from the satellite to the mobile receivers.

To optimize mobile reception late in the broadcast signal and the delayed early broadcast signal is combined as accurately as possible so that their respective characters match. This combination is achieved through the delay taken early broadcast signal by the same amount as the delay late broadcast signal received at the transmitter 24. On figa and 1b shows the corresponding principles of end-to-end data transfer. In the receiver 22 character combination of two broadcast signals is performed as accurately as possible using the fixed delay 26, which is the combination of early signal within less than a half period of the frame of the broadcast signal, followed by a variable delay adjustment which allows you to sync the politicization of the preamble headers of management services (the TOWN) (SCH) to the symbol in the early and late broadcast signals. The TOWN is described in application for U.S. patent registration number 09/112,349, filed July 8, 1998, which set forth fully herein by reference. Such a combination of characters for early and late broadcast signals enables the combination with a maximum likelihood symbol of early and late signals in the decoder 28 Viterbi receiver.

The combination with a maximum likelihood of early and late signals is performed in the transmitter 24 by obtaining them from the output of the convolutional encoder 30 and the separation of his output in the early and late signals. The division terminates the process known as predavanje indicated by the position 32. Preferably, predavanje includes a selection of half of the bits past the original convolutional encoding for the early signal, and the other half of the bits for the late signal. Is exact choice of bits constituting each half, thus, optimizing the General characteristics of the correction of bit errors for end-to-end data transfer. In the receiver recombination appropriately synchronized early and late parts of the broadcast stream by using a Viterbi decoder that implements the algorithm "soft solutions", provides an optimized combination of maximum likelihood. When such re is combinatii estimation is used the signal-to-noise ratio for each recombineering bit to create a combined result with the maximum likelihood.

Alternatively, instead of combining with the maximum likelihood, can be used seamlessly switch early and late broadcast signals. In this case, the receiver 22 is switched between the early and late broadcast signals. The output of the receiver 22, preferably, arrives late in the broadcast signal until this late in the broadcast signal will not be blocked. When it is locked, the receiver 22 is switched on early broadcast signal with a delay. The combination with the corresponding latency ensures no break in time at the time of switching of the receiver 22 between late and early broadcasting signals. The combination must be made within 10 milliseconds or less to exclude audible discontinuities. The signal will be lost only when early and late broadcast signals will be blocked simultaneously. This happens only if the duration of the simultaneous block exceeds the time delay between the early and late signals. However, the combination with a maximum likelihood algorithm Viterbi has a significant advantage in signal-to-noise ratio of approximately 4.5 dB compared with a simple switch.

1.1 Embodiment of the method using only the temporal is the first division with two direct flow of the MDBs in terms LPV from one satellite

Two threads ICBM designed for mobile reception, broadcast from the same satellite 14. One thread ICBM carries the symbols of the early broadcast signal, and another thread ICBM carries the characters later broadcast signal. Broadcast signals preferably contain many broadcast channels (VC). The number of broadcast channels VK, designed for mobile reception separation may vary from one to all available channels. Broadcasters VK that is not used for mobile reception with separation, can be used for the transfer of conventional services without separation in terms LPV provided on the stationary, stationary and portable radios. Early and late broadcast channels VK provide temporary division at the mobile receiver, which improves the ability of continuous reception in terms of dynamic blocking that occurs in a moving vehicle. 34 delay between the early and late channels VK, which is passed two flow MBP, is a system parameter that is defined in the same way as described above for the early and late broadcast channels VK crossed the same stream MBP.

In the receiver 22 a couple of broadcast channels VK, one of which is a late flow MBP and the other has the detainees earlier thread MBP, treated in the same way as the late and early broadcast signals described above with reference to figa. The receiver 22 receives two birdies MBP to implement this operation.

1.2 the Embodiment of Temporal and spatial separation using two direct flow MBP line-of-sight coming from two spatially separated satellites

You are passing two threads MBP intended for direct mobile reception by satellite in terms LPV, i.e. one thread 16 is transferred late signals and on another thread 18 are sending early signals. The threads 16 and 18 are received respectively from two spatially separated satellites 14 and 20, as shown in figure 2. This allows reception with spatial separation and time separation. Two satellites 14 and 20 are sufficiently spaced from each other in space to provide two different ways of streaming MBP. Thus, it is possible reception with spatial separation, as if one way is blocked, it is unlikely that another way will also be blocked. One thread 16 MBP arrives late broadcasters VK, and on another thread 18 MBP arrive early broadcast channels In which to provide temporary separation of the receiver 22 and improvement ensure continuous reception in the conditions of dynamic block, which occur in a moving vehicle. 34 delay between the early and late flow, m is a system parameter, which is determined as described above, for early and late broadcast signals demultiplexing from one signal MBP.

1.3 the Embodiment of temporal and spatial separation using two direct broadcast channels in conditions of direct visibility, each of which passes through one of the two spatially separated satellites

Two broadcast channel (i.e., one broadcast channel VK, which is information of a late signal, and another broadcasting channel VK, which supplies the information early signal), intended for direct mobile reception by satellite in terms LPV, transmitted every with its two spatially separated satellites 14 and 20, as shown in figure 2. The threads 16 and 18 ICBMs are not necessarily designed for all early or all late signals, but rather, each of them allows to transmit the combination of the two signals. This allows reception with spatial division and time division. Two satellites 14 and 20 are sufficiently spaced from each other in space to provide two different ways of receiving streams ICBMs. With specials can receive with spatial separation, because if one way is blocked, it is unlikely that another way will also be blocked. The use of early and late broadcast channels VK provides a temporary separation of the receiver 22 and improves the ability of continuous reception in the conditions of dynamic blocking, which occurs in a moving vehicle. 34 delay between the early and late flow, m is a system parameter, which is determined as described above, for early and late broadcast signals demultiplexing from one signal MBP.

On the receiver 22 a couple of broadcast signals (i.e. the one passed late signal and the other passed early signal) is treated in the same way as the late and early broadcast signals described above when considering figa and 1b. To implement this operating mode, the receiver 22 receives two bearing ISI. Spatial separation, essentially, by using the same processing schemes that perform temporal partitioning, as described above, there is used a combined processing 28 Viterbi maximum likelihood, which is simultaneously embodied as a temporary separation and spatial separation. Alternatively, can use a simple switch to vibrosignal with the best reception quality.

As mentioned above, the receive spatial separation leads to the fact that since the early broadcast signal comes from a satellite 14, late broadcast signal comes from a satellite 20, (or Vice versa), and the satellites 14 and 20 are located at different places in space, as shown in figure 2. Different positions in space can be obtained through the use of satellites located at different points on geosynchronous orbits, or two satellites at different elliptical orbits are tilted with respect to the equator and with the appropriate synchronization sidereal phase of the day, to ensure continuous coverage of spatial and temporal separation, for example, in the target area. In the latter case, it is necessary to use, for example, three or four satellites at different elliptical orbits with high inclination, two satellites of which are used simultaneously to provide a spatial separation at high latitudes.

2. Terrestrial re-radiation to receivers that have blocked line of sight from the satellite.

Any of the above variants of the embodiment of the direct satellite explode in terms LPV can be combined with a network of 36 ground-based transmitters are then re-emitted (figure 4) for exceptions block created by the buildings, mostley tunnels, which manifest themselves both in towns and in rural areas where direct reception from satellites in terms LPV may not be available, and to maintain continuous reception of signals of broadcast programs on the mobile receivers. Terrestrial network 36 may contain from one to an arbitrary number of stations 38, in accordance with the need for the working zone of radio broadcasting, for example, in the city or on the highway.

It should be understood that there is also the option of mobile reception, which uses the direct broadcast transmission without temporal or spatial separation, which is only connected with the ground network of reemission. This option is effective in areas of coverage beam of the satellite, where, for example, the elevation angles LPV on satellite accounts for 85° and more, and blocking obstacles rarely happens. Under such conditions, the terrestrial re-radiation requires only a few, relatively small isolated locked areas. The choice of the threshold level for switching between satellite and terrestrial reception is described below.

For the best use of land reemission or direct signal from the satellite, repeated on terrestrial networks, they must be synchronized and combined with the direct signals in terms of the s LPV satellite in the mobile receiver. In accordance with the present invention, will be described below sync for mobile receive diversity using one or more direct flow from the satellite in terms LPV using ground reemission or without network 36 land retrotranslator. In the following description, it is assumed that the signal transmission is performed using multiplexing time division. This does not mean that it is impossible to use other transmission schemes, such as multiplexing frequency division or multiplexing code division of channels in any combination of such methods of multiplexing.

Bearing, taken directly from the satellite in terms LPV equipped for spatial and temporal separation, allow you to send messages to mobile receivers in non-blocked or partially blocked agricultural areas with high reliability, using the methods mentioned above. However, for low, medium and high-rise buildings, which are often found in cities, can significantly block the reception from the satellite in terms LPV. This requires a ground system reemission to improve reception by satellite in terms LPV and allow high what hadinoto as in the cities, and in rural areas.

To overcome the block in terms LPV, use the network 36 ground stations 38 reemission located in various places in the city, as shown in figure 4. Each ground station 38 reemission produces the signal is reliably protected from interference resulting from multipath propagation, and repeats a direct digital stream ICBM satellite in terms LPV or selected components (e.g., broadcasters) this thread ICBMs. All ground station 38 reemission, preferably, make the transfer, essentially, on the same carrier frequency. Bandwidth of their signals coincide with each other. Such a network is often called a network with a single frequency. Used, for example, such signal processing as: 1) multiplexing time division - multi-frequency modulation (MBP-MISI), using the proven technology of multipath propagation, known as orthogonal division multiplexing frequency (OMDC) for signal transmission ICBMs; 2) adaptive mode ICBM, which is signal transmission ICBMs containing special periodic digital customized sequence, which allows using multibeam adaptive equalizer based on the pair correlation is ora, multi-tap delay line and additional signal processing to produce the control output signals of the equalizer for constructive recombinant separate the received signals on different pathways for recovery of the transmitted signal; and 3) multiple access code division (mdcr)(SOMA), in which the satellite signal MBP is divided into component parts, such as the Channels of the main thread (SHORT) (PRC), and these parts are re-transmitted in the form of multiple simultaneous signals mdcr, which occupy a total bandwidth and separately identified and discriminated against in the receiver using digital codes, irregularly appointed for each CDF. KOR described in the aforementioned application for U.S. patent registration number 09/112,349, filed July 8, 1998, which is given here as a reference. Broadcast signals VC and the ISI can be separated, for example, COR. COR can be transmitted to the bearing encoded mdcr. The receiver can accumulate coded mdcr COR for VK and reassemble VK.

Below is selected embodiments using signal MVP-MISI for ground reemission, the term signal MVP-MFM is used to refer to digital modulation symbols of the signal MBP taken directly from SPU is nick on mnogochastotnom-modulated symbols (MFM symbols). An important property of this variant embodiment is sync ground pereizluchennykh signals MBP-MFM flow MBP, received from the satellite. It should be understood that this synchronization between the signals MBP, transmitted via satellite, and any other signals used for terrestrial re-emission, one must also consider the difference in the delay spread between the satellite and ground stations and reemission between ground stations of reemission and receivers.

2.1 Embodiment terrestrial reemission using MBP-MISI

There are various options for transmission from the satellite. They are: 1) one direct the flow of the ICM satellite in terms LPV using the same satellite effecting the transmission of broadcast signals without any temporal or spatial separation; 2) one live stream of the ICM satellite in terms LPV from the same satellite, which is the transfer of both early and late broadcast signals; 3) two different streams of the ICM satellite in terms LPV, with the same companion (that is, one thread is late transfer channels VK and other flow is the transfer of early channels VK); and 4) two direct flow MBP from different satellites in terms LPV (for example, one is OK MBP, through which you are passing a late channel VK and another thread MBP, which is the transfer of early channels VK, or so that each of the threads are passing a combination of late and early channels VK such that for each late channel VK accompanying early channel is transmitted on another thread MBP).

In the first case, when not in use temporal or spatial separation, the flow of the MBP, which is transmitted VK, accepted and immediately repeats the ground station 38 reemission using signal MVP-MISI. In this case, the receiver introduces a delay in the received signal ICBM satellite in terms LPV due to delays on the processing and transfer in the land of reemission. In three other cases to delay the flow of the MDBs, which is the transfer of early channels VK and repeat its ground station 38 reemission using signal MVP-MISI.

The bit stream or bit streams ICBMs, selected and transmitted through signal MVP-MISI, preferably, transfer the contents of the identical coming from the satellite. Alternatively, MBP-MFM can be selected from satellite streams ICBMs only those channels VK, which are designed for mobile reception. In the latter case, the remaining capacity of threads ICBMs can be used in agreeme local content broadcast channel, designed for mobile receivers.

In accordance with the present invention, for configurations that use the receive time division, each ground station introduces a delay, which is adjustable so that the arrival time of the early channel VK in the centre of the terrestrial broadcasting area coincided with the arrival time of the associated late channel VK satellite. This delay includes adjusting, taking into account the difference in distance between each station 38 and the satellite, as well as the difference of the distances between each station 38 and the center region 42 40 terrestrial broadcast zones and delays in processing associated with the flow transformation ICBMs LPV in the flow of MBP-MISI.

Because of the requirement for close matching of the time of arrival of a signal ground reemission and late signal from the satellite to the center 42 of terrestrial broadcasting area minimum time difference of their arrival turns inside and on the outer border region 40 terrestrial broadcast zones. In accordance with the exit region 40 terrestrial broadcast zones and the entrance to it is "switching" between terrestrial and satellite signals without noticeable interruption, for example, the incoming audio signal. The same order of combination, which are applied to each terrestrial repeater station, provides the coincidence in time ifase characters MISI each ground station, arriving in the center of the terrestrial broadcast zones, which optimizes the quality of reception on a mobile platform. As the mobile receiver moves away from the centre ground broadcast zones, the values of the time of arrival of MISI be scattered in time and phase. Structurally, the dispersion can reach the value of the guard interval, which is entered in the symbol period MISI, and usually is 60 microseconds and allows to compensate the distance up to 9 km from the centre of the zone broadcast.

In accordance with the present invention, each transmitter reemission produces the re-radiation of its own signal MVP-MISI using the distribution of terrestrial radio waves received with the help of a powerful transmitter. The radiated power may not exceed 0 dBW for small areas broadcast zones with rare blocking up to 40 dBW for large areas of broadcast zones, such as in the Central business districts in large cities. The signal emitted from the towers at a height sufficient to overcome the blocking of the surrounding objects, taking into account natural features of the terrain such as hills and tall buildings. In addition, the signal radiate along the highways with appropriate directional antennas with narrow beam of radiation that are installed on towers at a height sufficient to ensure the distance reception from 2 to 16 km is the use of terrestrial radio.

2.2 Switching between satellite signal LPV and re-radiated by the ground signal.

The term "switch" refers to the occasion, which occurs when the vehicle in which you are mobile reception, carries out the transition between reception of the MDBs in terms LPV satellite and terrestrial reception MBP-MISI terrestrial single frequency system. There are two methods of switching. Both of them were already described in the previous sections. Technology "switch" can be implemented by combining the preambles of the control headers (e.g., through combining terrestrial and satellite channels VK their correlation peaks). This process allows you to precisely synchronize terrestrial and satellite symbols channels VK and can be combined with maximum likelihood using the decoder 28 Viterbi.

Alternatively, the above technology is used to switch between terrestrial and satellite signal instead of combining them with the maximum likelihood. Mobile receivers and configured to accept one or both of load-carrying satellite signal MBP taken in conditions LPV, and terrestrial radiation SFN on bearing ISI-MISI. Bearing both types convey the same channels VK. At any given point in the receiver 22, preferably selects the signal (that is here, LPV MBP or MBP-MFM), which provides the best quality channel VK. The reception quality can be measured using the frequency of occurrence of erroneous bits (hospital has no facilities)(BER) in each accepted stream of bits. Switching is performed on the basis of differences in hospital has no facilities as follows:

Switching from LPV on MBP MBP-MISI, when MBP-MISI hospital has no facilities≤LPV MBP hospital has no facilities -Δ1 hospital has no facilities; and

Switching from MBP-MISI on LPV MBP when LPV MBP hospital has no facilities≤MBP-MISI hospital has no facilities -Δ2 hospital has no facilities.

Use Δ1 hospital has no facilities and Δ2 hospital has no facilities, as described above, prevents the occurrence of spurious oscillations when switching between LPV MBP and MBP-MISI. If Δ2 hospital has no facilities>Δ1 hospital has no facilities, switching from MBP-MISI on LPV MBP will be more difficult than with LPV on MBP MBP-MISI. This is preferred because when entering the area of broadcasting in the city, the receiver 22, preferably, should remain in receive mode MBP-MISI, as soon as he begins to receive signals MBP-MISI. As an example of this mode of operation, assume that in the region of 40 LPW MBP hospital has no facilities=10-1and that Δ1 hospital has no facilities=Δ2 hospital has no facilities=10-2. Switching from LPV on MBP MBP-MISI happens when 0,01-0,001=0.009, and switching from MBP-MISI on LPV MBP again occurs when = 0,01=0,001=0,011. Thus, more easily go with LPV on MBP MBP-MISI than with MBP-MISI back to LPV MBP. If you set Δ2 BER=4×10-2switching back to MBP-MISI on LPV MBP Boo is et to occur when MBP-MISI hospital has no facilities=0,015, which makes more difficult the return on LPV MBP after the selected ground MFM mode. Instead of the hospital has no facilities can be used by some other equivalent measures of quality, such as signal-to-noise.

2.3 the Embodiment of terrestrial transmission MBP-MISI

The characters of satellite data stream MBP conditions LPV, preferably precisely aligned with the subcarriers OMDC within data symbols MBP-MISI to achieve optimum performance, the single-frequency system. In the present variant embodiment, each data symbol MBP contains 2 bits. In accordance with the present invention, exactly the same 2 bits designate the same subcarrier ADC in the signal MVP-MISI, generated each terrestrial re-radiation of single frequency system 40. This combination is identical in each station 38 ground reemission, because any deviation from this alignment in any ground station reemission network can turn MBP-MFM in the source of the interference and, therefore, reduce the quality of reception.

To combine the data symbols MBP for each character MFM signal MVP-MISI used method depicted in figure 5. First, the data symbols of the ICM from the flow of the ISI, which is the transfer of early channels VK, taken from a satellite, build into a sequence of continuous time blocks. Each symbol MV which contains 2 bits. Each block 44 character data, m contains M columns and N rows. M and N are design parameters defined structural characteristics of the transducer of the type of seal channels MBP-MISI. The earliest symbols MBP fill the first row of the matrix, following an early - next line and so on, up until the last line will not be filled symbols frame MBP. Each block 44 is fed to the input of block 46 inverse fast Fourier transform (OBPF). As a result of work OBPF formed one character 48 MISI containing N bearing OMDC, i.e. one carrier for each character string data of the ICM. Each carrier OMDC subjected to differential modulation method is quadrature phase-shift keying (CFM)(QPSK) with respect to the added carrier reference phase. Thus, each symbol contains MFM N+1 bearing. This process is sequentially repeated for all M columns of the block of data symbols MBP to form the complete frame 50 character MFM. M columns of block 44 m generates M time-serial characters 48 MFM, each of which contains N bearing plus one carrier reference phase. Thus, constitute the frame 50 MVP-MISI. The total number of data characters MBP transmitted in frames MBP-MISI is M×N. it Should be understood that the values for M=8 and N=6, pokazannye 5, provided only as an illustration. Such values typically be on the order of, for example, M=960 and N=116.

For optimal performance SFN MBP-MSM each character 48 MBP-MISI transmitted from each ground station 38 are then re-emitted in the network 36 has the same characters of data ICBM unit on the same carrier frequency of each character MISI; otherwise it will be impossible to carry out constructive recombination among the many characters 48 MBP-MISI received at the receiver 22 from the various ground stations 38 are then re-emitted in a single frequency network 36. The synchronization symbols in the modulation of MBP - in - MFM and the process of combining are performed independently, but in exactly the same way in each ground station reemission.

The formation of characters 48 MISI in frames 50 MVP-MISI additionally presented on Fig.6. Stream MBP that transmits 2 bits per symbol, with the speed of R symbols (for example, the bit rate BR=2×R) is presented at the input OBPF in sets of NMBPsymbol 52. Characters, preferably written in the form of complex values of I and Q are in the form of columns of the matrix before serving in OBPP. OBPF 46 of dimension 2n converts NMBP MBP character 52 in NMBP bearing by quadrature phase-shift keying (FMC) to generate each character MBP-MISI, as indicated by positie the 54 figure 6. The values of I and Q above, directly determine the phase of each carrier MISI OMDC with modulation of the FMC. Each character MBP-MISI, therefore, contains NMBP bearing OMDC, which cover the period Tsym=NMBP/R.

Therefore, the speed of the characters MFM=R/NMBP. The number of samples in time domain for a period equal to 2n. Therefore, the frequency modulation of the output symbols MISI time domain from ABPF 46 is 2n R/NMBP. As indicated by the position 56, the guard interval is generated, which is part of a η period character. This action causes the compression of time (1-η)-1the output signal OBPF. To build the frame MBP-MISI once add synchroscope 49 frame for each of the characters MISI MMCM, thereby further enhancing the compression of time (MCM+1)/MMCM, as indicated by the position 58. The bandwidth of the signal MVP-MISI is, thus, R(R/S)((1-η)-1)(MM4M+1)/MMCM.

The parameters used when the modulation symbol of the MBR - in - MFM (for example, the frequency R of the characters in the stream ICBMs, the number of NMBPcharacters IBM character MISI, number 2ncoefficients OBPF, share η guard interval and the duration of MMISIframe MBP-MISI) is chosen to obtain a whole number of frames 50 MVP-MISI on the frame 64 ICBMs (Fig.9). This choice allows you to use the preamble of the main frame ICBMs for C the chronicity of the frame MBP-MISI. OBPF takes 2ninput coefficients simultaneously. Number 2nmust be equal to or greater NMBP. Thus, only NMBPsubcarriers OMDC with nonzero coefficients 54 spectrum allowed as input signals in OBPF 46. The selected values of the coefficients of NMrepresent values that szentivanyi in the spectrum window OBPF. Unused coefficients OBPF at the edges of the window OBPF are set to zero.

2.4 Synchronization of data characters MBP and data characters MBP-MISI.

As indicated above, the earth station 38 reemission MBP-MISI, preferably working in a single frequency network 36. A single-frequency network 36 includes many ground stations 38 are then re-emitted, which produce a re-transmission of at least part of the early satellite signal MBP adopted in terms LPV. All ground station reemission produce a transmission bandwidth of a single carrier frequency. Each ground station of reemission will re-broadcast the same signal MVP-MISI, who represent all of their associated signals. Each ground station of reemission produces receive and delay the same satellite signal MBP adopted in terms LPV, which is the transfer of early channels VK this magnitude, h what about the demodulated stream MBP, transmitted on the carrier frequency of MBP-MISI, synchronized with the time of arrival of the satellite signal MBP conditions LPV, which passed late channel VK in the center of the zone broadcast single frequency network. Symbols satellite MBP taken in conditions LPV, which is the transfer of early channels VK, accurately and consistently assigned bearing OMDC of data characters MBP-MISI, as described below with reference to figure 4, 5 and 6.

Station 38 network 36 are located so as to ensure optimization of broadcast zones in and around the city using the minimum number of stations. In accordance with the present invention, the correction of the delay time introduced by ground stations 38 are then re-emitted so that the arrival time of the MFM symbols, which is the same satellite data characters ICBMs would be approximately synchronized in the center 42 or broadcast zones. You want to use three types of correction delay time. Two correction delay time include the correction distance. One is a correction of the difference of the distances between the individual ground stations are then re-emitted and the satellite, and the second is the correction of distances between each ground station then re-emitted and the center of the zone broadcast single frequency network. The calculation of these two correspondent of the capabilities of delay described below.

The third correction delay is introduced so that the signal MVP-MISI come in phase in time with the late satellite signal received in terms LPV, the mobile receiver located in the center of the zone broadcast single frequency network. This should be done as early signal VK ICBMs in terms LPV satellite is used to generate a ground signal reemission MBP-MISI. The joining zone broadcast this delayed signal should occur at approximately the same time as the late arrival signal VK ICBMs taken in conditions LPV satellite. To this end, the amount equal to the delay between the early and late signals must be delayed to early signal VK ICBMs taken in conditions LPV satellite. Some values of this delay occurs due to the delay processing in the conversion process seals signal channels MBP-MISI. The remainder of the delay is introduced by the digital delay line through which passes the flow of ICBMs before the conversion process seals signal channels MBP-MISI.

There can be multiple "centers zone broadcast single frequency network for optimization of General acceptance within the boundaries of the city and its surroundings. Subset of ground stations 38 are then re-emitted in a single frequency network 36 can be focused on different penny is s broadcast zones within the city and its surroundings because of the nature of the distance, grouping and blocking. These factors affect the first two corrections above.

3. Correction synchronization station reemission depending on the distance to the satellite and the centre of the zone broadcast single frequency network.

As described above, the correction of synchronization are performed to synchronize moments to joining the center of the zone broadcast single frequency network signals MBP-MISI re-radiated from stations 38 due to:

a) different points in time of arrival of the satellite signals MBP at station 38 are then re-emitted from the satellite 14 or satellites 14 and 20 and

b) different values of the transmission time due to differences in the distance between stations 38 are then re-emitted and the center zone 42 broadcast single frequency network.

The difference in synchronization can be entered at each station are then re-emitted by the delay of data characters MBP flow MBP at an appropriate time in the storage device before putting them in OBPF 46.

3.1 Difference synchronization with the satellite on station reemission MBP

Consider a network of 36 ground stations 38 are then re-emitted, which take the MBP signal from the satellite. When the elevation angles different from 90°i.e. in the case of a location directly above the head, the distance between each ground station then re-emitted and the satellite will be different. Thus, there are differences in the range in the womb between the location of each ground station and reemission companion and therefore, the time of signal arrival MBP. In addition, the distance between each ground station 38 reemission and the center zone 42 broadcasting will be different. The following scenario illustrates the magnitude of these time differences that arise from differences in the distance.

For illustration purposes, consider a single-frequency network 36 are then re-emitted, which contains several ground stations 38 reemission, geographical location of which is selected for the adequate coverage area of the broadcast in the city and related peri-urban areas. In a relatively simple, small and constrained topologies block enough to use a small number of ground stations of reemission. In larger, more complex topologies block you want to use a larger number of ground stations are then re-emitted.

The method of calculating the difference of the delay caused by differences in the range of inclined distances between ground stations 38 are then re-emitted and the satellite 14, shown in Fig.7. The difference between the distance measured between perpendiculars to the line of sight of the satellite, which lie on the surface of the Earth at the point of intersection at the location of each station. Denote closest to the satellite station in the network 36 figure 1, the far - m and any intermediate - k. Let the difference of the distance between the perpendiculars to LPV along the surface of the ground in the direction the AI azimuth towards the sub-satellite point between any station k station m is d kmThus, the distance between the most distant station m and station 1 is d1m=dmax. It should be noted that 7 is the most distant station is marked by the number 3, the nearest station is marked by the number 1, and also presents one station between them, marked by the number 2. Let the corresponding distances inclined range LPV are ΔTslantk and ΔTslantmax. Let the elevation angle to the satellite is elv for all stations. It should also be noted that the azimuth at the sub-satellite point is assumed approximately equal for all stations. Thus, using geometric drawing on Fig to calculate the directional distance line of sight for the time differences of arrival of the satellite between stations k and m, apply the following dependencies:

0<ΔTslantk<ΔTslantmax

where:

ΔTslantmax=(d1m÷c)×cos(elv)

ΔTslantk=(dkm÷×cos(elv)

C = speed of light in m/s

It should be noted that the component ΔTcorrectkcorrection synchronization, applicable to any station k, to account for the time difference of arrival of the signal from the satellite to the receiver MBR is defined as follows

ΔTcorrectk=ΔTslantmax-ΔTslantk

Thus, the further station is 36 from the satellite, the smaller the correction of the synchronization the AI is required. For example, consider the case where d1m=dmax=18 km and elv=30°. For this case ΔTslantmax=52 ISS. For station 1, nearest to the satellite, the correction is equal to ΔTcorreckt1=ΔTslantmax=52 ISS. For the station on the maximum distance it will be equal to ΔTcorrectm=0. For all other stations k, located between them, ΔTcorrectkis given by the equation above.

For the zone broadcast single frequency station near to the ground point, the azimuth angle to the satellite for each station 38 reemission differs from station to station, and it is obvious that you want to enter the corresponding correction in the above equations, for example the contours of constant propagation delay between the station and the satellite, in fact, represent the circles on the Earth's surface with the center in the sub-satellite point, and the time difference is measured between these circles. At large distances from the sub-satellite point and within essentially bounded domain zone broadcast single-frequency network, the circles can be considered as straight lines.

We will look at the changes in the difference of time due to the motion of the satellite. The calculations above are applicable to the plane of the azimuth crossing the satellite, the center of the Earth and consider each ground station. For a satellite in a geostationary orbit put the e satellites in orbit varies slightly. The usual practice is to maintain the position of the satellite within a cube with a side of 50 miles (80.5 km), the center of which is assigned to the location of the satellite's orbit. At distances from 21300 up to 25600 miles (34293-41216 km), the resulting deviation in azimuth and the elevation angle caused by variations in the position of a satellite in a geostationary orbit, has a negligible effect on the calculation time correction above. Here its value does not exceed 135 nanoseconds peak-to-peak. Similarly, there are differences in time, due to differences in the locations of the ground stations within the system 36. They do not exceed 31 nanosecond peak to peak. When these two values are summed, the result does not exceed 166 nanoseconds peak-to-peak.

However, for satellites in non-geostationary orbits such as satellites, flying in orbits Tundra, Lightning, intermediate circular orbit (FFP)(ICO) and Low earth orbit (IEO)(LEO), in the above calculations, preferably, should be considered a permanent change of angles of azimuth and elevation of the satellite relative to the stations 38 are then re-emitted. With regard to satellite communications technologies, the calculation process is an extension of the method given above. In addition, for such non-stationary orbits calculation requires the I repeat with frequency, which allows you to maintain synchronization error due to the inclined path in terms LPV within +-500 nanoseconds.

3.2 Protective time interval and the diameter of the zone broadcast single frequency system

The signal MVP-MISI, transmitted from the various ground stations 38 reemission, single-frequency system 36 contains frames 50 MVP-MISI generated thereby, as described above with reference to figure 5 and 6. In the receiver 22, located in the intended zone 40 broadcasting, various signals containing frames MBP-MISI come from various stations of reemission. The time of their coming overlap each other as shown in figure 10. The distribution of the overlay depends on the differences in distance from the satellite to the ground station then re-emitted and differences of the distances from the stations are then re-emitted to the receiver. Frames MBP-MISI are combined in a constructive manner, provided that the difference between the time of their arrival at the receiver 22 does not exceed the width of the guard interval ΔTGused to generate a signal of MBP-MISI. If the width of this guard interval is equal to ΔTGthen the difference of time coming from all stations of reemission OP, preferably, should not exceed ΔTGand the difference of the distances, preferably, should not exceed×ΔTGwhere C is the speed with the ETA. Thus, the structure for the maximum diameter of the distribution of terrestrial stations 38 are then re-emitted in a single-frequency system 36 is shown figure 11, where one transmitter 38A ground station reemission is located diametrically opposite with respect to another transmitter 38b at a distance D=C×ΔTG. Thus, if all ground station re-emission are within the sphere of diameter D=×ΔTG, the time difference of arrival ΔTRframes MBP-MISI on any receiver within or outside the region, equal to ΔTR<ΔTG. If, for example, ΔTG=60 microseconds, this diameter is 18 km.

In the above description assumes that the transmission time of the frame MBP-MISI from each station 38 single frequency system 36 is adjusted so that the time of arrival for all frames in the geometric center region 42 40 broadcast zones were essentially just combined, i.e. the time difference of arrival for all frames 50 MVP-MISI were essentially zero. To this end, the transmission time from each ground station re-emission is compensated for two types of the difference between the distances in accordance with the present invention. As described above, the first type of correction is the difference of the distances between each station 38 and sat the com 14. The second type of correction is the distance between the location of the station 38 and the center region 42 40 broadcast zones.

3.3 calculation Procedure for the correction of the synchronization frame MBP-MISI

The procedure for implementing the desired alignment of the frames 50 MVP-MFM in the center of the zone broadcast terrestrial re-emission will be described below. This procedure is preferably performed independently in each ground station 38 reemission single-frequency system 36. 7 shows the location of the ground stations 38 reemission single-frequency system 36, the distances used in the calculations and equations used. After the procedure steps illustrative example.

For analysis of the structure described above with reference to Fig.7, it can be seen that each ground station 38 reemission indicated by the index "i", which will change from i=1 to station, located at the nearest distance to the satellite in terms LPV, up to i=m, for a station located at the farthest distance from the satellite in terms LPV. Other stations in the area of broadcast zones are numbered in ascending order from 1 to m, with increasing distance in terms LPV. Then determined by the difference between the horizontal distance dimbetween the Parallels passing through each station i until station m. It should be noted that these parallel the spruce perpendicular to the direction LPV to the satellite for each station. It should also be noted that for the example shown in Fig.7, the number m corresponds to station 3.

The difference dimhorizontal distance transform on the difference between the distances LPV by multiplying by the cosine of the elevation angle, as shown in Fig. Then the distance is measured Dicbetween each station i and the center zone 42 broadcast. Uncorrected sync Δti for each station i is determined using:

Δti=[(Dic+dim*cos(elv)]/s

where elv - elevation angle to the satellite, and s is the speed of light.

Calculations from the equation produced for each station, the re-emission single-frequency system. In the next step determines the minimum value of Δti, denoted as Δtimin. Then is determined by the adjusted sync Δti for each ground station reemission i as follows:

ΔTi=Δti-Δtimin

Adjusted sync Δti is used in each ground station i then re-emitted to combine the time of arrival to obtain a zero displacement in all frames MBP-MFM in the center of the zone broadcast single frequency system. The use of such a synchronization correction optimizes the overall surface re-emission of the ICM-MISI single-frequency system. Example calculations for the case m=3 illustrirovanniy of the present invention, where dn3represents the horizontal distance from station n to the farthest station along the azimuth to the satellite, and Dcnis the distance from station n to the center of the zone broadcast.

Correction of synchronization used in each station of reemission ∠Elv=30°

d13=18 kmD1c=15 kmΔt1=102 ISSΔT1=32 ľs
d23=15 kmD2c=10 kmΔt2=76,6 ISSΔT2=6,6 ISS
d33=0 kmD3c=21 kmΔt3=70 µsΔT3=0 ISS

The correction values synchronization, above, allow you to compensate for the difference in distance between the satellite and each station then re-emitted, and the difference of the distances between each station and reemission the center of the zone broadcast single frequency system. In addition, each station must be entered delay to compensate for the offset between the early and late signal from the satellite and processing delay in the inverter type seals signal channels MBP-MISI. The total delay introduced in each station must be such as to ensure an exact match late satellite signal with a signal emitted from che the ez each ground station reemission. Thus, if the delay between the early and late signals denoted as TELand the processing latency be described as ΔTPthen the total delay ΣTi at each station I is equal to

ΣTi=TEL-ΔTP-ΔTi

For the above example, if we assume that TEL=5 seconds ΔTP=0.2 seconds, the total delay for each station will be

ΣT1-5,0-0,2-32,0×10-6
ΣT2=5,0-0,2-6,6×10-6
ΣT3=5,0-0,2

1. How to synchronize a selected number of multiplexed time division (IMM) characters in the data stream MBP with an equal number of subcarriers multiplexed time division mnogochastotnom-modulated (MBP-MISI) symbols in the signal MVP-MFM in the ground device, comprising stages:

receiving a data flow of the ICM satellite

code definition in the preamble of the main frame or distributed synchronization sequence in the data stream MBP containing at least one frame MBP containing the code of the preamble of the main frame or distributed synchronization sequence, and many of these characters, and the code of the preamble of the main frame and the and distributed synchronization sequence is used to define the frame of the ICM in the data flow MBP,

generating a matrix using the specified characters in the frame MBP containing a number of columns corresponding to the first number, and a number of rows corresponding to the second number;

generating symbols MBP-MFM in an amount corresponding to the first number, using inverse fast Fourier transform (OBPF) in respect of the said matrix, and each of the symbols MBP-MISI includes a second specified number of subcarriers for the corresponding characters of the ISI in the relevant specified rows and the first number of characters MBP-MISI corresponds to a frame of symbols MBP-MISI; and

the re-emission of the specified characters from the data stream MBP via the ground station then re-emitted in the form of a signal MVP-MISI.

2. The method according to claim 1, characterized in that the step of generating includes a step of filling the matrix by placing the first incoming character MBP frame MBP in the first generated the string specified matrix and consistent fill these rows until then, until it filled the last line of the last symbol of the ISI in the frame MBP.

3. The method according to claim 1, characterized in that the data flow MBP contains many frames MBP, and the frame characters MBP-MISI has essentially the same length as the frame MBP./p>

4. The method according to claim 1, characterized in that the step of generating includes a step of synchronizing symbols MBP-MFM in the frame of symbols MBP-MISI within a fragment of one of the specified characters in the data stream MBP.

5. The method according to claim 4, characterized in that the number of characters MBP-MFM in the frame of symbols MBP-MISI is an integer.

6. The method according to claim 1, characterized in that it further comprises the step of incorporating a protective time interval in each of the characters MBP-MFM in the frame MBP-MISI, and the period character MBP-MISI matches the second number divided by the number of characters MBP per second, while the protective time interval is chosen smaller than the symbol period, m-MFM.

7. The method according to claim 1, further containing the step of enabling synchroscope in each character MBP-MFM signal MVP-MISI.

8. The method according to claim 1, characterized in that it further comprises the steps:

the inclusion of the guard time interval in each character MBP-MFM in the frame MBP-MISI, and the period character MBP-MISI matches the second number divided by the number of characters MBP second, with the guard interval is chosen smaller than the symbol period, m-MISI;

the inclusion of synchroscope in each frame of symbols MBP-MFM signal MVP-MISI and

compressing each of the characters MFM-MBP to compensate enter the safety interval and synchroscope in each frame of symbols MBP-MISI so, what characters MBP-MISI containing protective time interval, and temporal location corresponding to the specified synchroscope for the corresponding frame MBP-MISI, within one frame period MBP.

9. The method according to claim 1, characterized in that OBPF using a larger number of coefficients than the second specified number of characters.

10. The method according to claim 1, characterized in that the data flow MBP contains many frames MBP, and the specified step of generating further comprises the step of assigning symbols in the respective frames of the ICM in the data flow MBP subcarriers characters MBP-MFM in accordance with the staff MBP-MISI.

11. The pickup device and synchronization for use in ground stations reemission containing;

the tool receiving multiplexed time division (ISI) data streams containing characters, each of which corresponds to the selected number of bits in the specified data stream; and

a processing device connected to the pickup device and executed with the ability to highlight code in the preamble of the main frame or distributed synchronization sequence in the data stream MBP containing at least one frame MBP containing the code of the preamble of the main frame or distributed synchronization sequence, and many of these bits and the code of the preamble of the main frame and distributed synchronization sequence used for frame selection MBP from the data stream MBP;

when the processing device is configured to convert the symbols in the data stream MBP corresponding subcarriers to generate a multiplexed time division mnogochastotnom-modulated (MBP-MISI) signal containing symbols MBP-MISI, each of which contains the selected number of subcarriers used code in the preamble of the main code or distributed sequence for synchronization of these characters in the data stream MBP with the corresponding subcarriers in the respective characters MBP-MISI before re-emission flux data in the form of a signal MVP-MISI via the ground station then re-emitted.

12. The device according to claim 11, characterized in that the processing device uses the inverse fast Fourier transform (OBPF) to convert characters in the data stream MBP corresponding subcarriers.

13. The device according to item 12, characterized in that the frame MBP-MISI contains the selected number of characters MBP-MISI, and a processing device configured to generate an integer number of symbols, m-MFM to frame the ISI in the data flow MBP.

14. The device according to item 13, wherein the processing device is configured to provide the frame characters MBP-MISI same characters that are contained in the corresponding CA is re MBP.

15. The device according to 14, wherein the processing device is configured to assign the symbols in the corresponding frame MBP respective carrier frequencies characters MBP-MFM in the frame of symbols MBP-MISI.

16. The device according to item 15, characterized in that is used in the ground station then re-emitted, which is made capable of receiving a data stream MBP and convert the contained symbols in the corresponding frequency subcarriers to generate frames MBP-MISI containing the characters MBP-MISI, and the processing device is configured to assign symbols in the respective frames of the ICM in the data streams MBP subcarriers frequencies characters MBP-MFM in the respective frames MBP-MISI.

17. Acquisition and synchronization for use in ground stations reemission, containing

the receiver is configured to receive multiplexed time division (ISI) data flow from satellite;

transcoder connected to the receiver and configured to convert a data stream MBP mnogochastotnom-modulated (MFM) signal to generate a multiplexed time division mnogochastotnom-modulated (MBP-MISI) signal; and

a transmitter connected to the transcoder and configured to transfer signals is and MBP-MISI.

18. The system of 17, wherein the transmitter is configured in such a way that allows you to pereizuchit signal MVP-MISI on terrestrial paths at a distance, essentially, from 2 to 10 km in areas where reception from the satellite is blocked.

19. The system of 17, wherein the transmitter is configured with the possibility of re-emission signal MVP-MISI on terrestrial paths at least in the town and along the highway at a selected distance in areas where reception from the satellite is blocked by buildings and trees, respectively.

20. System 17, characterized in that is included in many of these systems are located in their respective ground stations then re-emitted in SFN and running essentially simultaneously with the use of timing and synchronization with respect to each other to achieve essentially continuous signal reception MBP-MFM in the area, interconnected with the specified single-frequency network.

21. The system according to claim 20, characterized in that the ground station reemission geographically located in such a way that they serve the city and surrounding suburban area.

22. The mode of transmission of the broadcast channel in a data transmission system with time division, in which the early signal and late signal is transmitted, at least one satellite, n is ICEM early signal contains, at least part of the broadcast channel, and a late signal corresponds to the early signal, but delayed for a selected period of time in relation to the early signal and the data transmission system includes a network of ground stations reemission for receiving and processing the early signal and to transmit a ground signal is then re-emitted, contains stages

determining respective differences of the distances between the satellite and each of the ground stations then re-emitted in the network and

correction signal ground reemission to compensate for differences in time of arrival of early signal in the respective ground stations reemission.

23. The method according to item 22, wherein the network is a single frequency network.

24. The method according to item 22, characterized in that it further comprises the steps:

determining at least one of the approximate center of the broadcast zone for the selected number of ground stations of reemission;

the definition of the relevant differences of the distances between each of the ground stations then re-emitted and the approximate center of the area of broadcasting and

the correction signal ground reemission to compensate for different moments of time of his coming from the ground stations then re-emitted at the receiver due to the difference in distance between the respective ground stations and reemission approximate center of the zone broadcast.

25. The method according to item 22, wherein the step of adjusting includes a step compensate for the delay in converting the satellite signal in the signal ground of reemission.

26. The mode of transmission of the broadcasting program in the data transmission system with time division, in which the early signal and late signal passed at least one satellite, at this early signal contains at least a portion of the broadcast program, and a late signal corresponds to the early signal, but delayed for a selected period of time in relation to the early signal and the data transmission system includes a network of ground stations reemission for receiving and processing an early signal, and to transmit a ground signal is then re-emitted, comprising stages:

determining at least one of the approximate center of the zone broadcast among the selected number of ground stations of reemission located separately from each other geographically;

the definition of the relevant differences of the distances between each of the ground stations then re-emitted and the approximate center of the area of broadcasting and

the correction signal ground reemission to compensate for different moments of time of his coming from the ground stations then re-emitted at the receiver due to differences in the distance between itemname stations and reemission approximate center of the zone broadcast.

27. The method according to p, wherein the step of adjusting includes a step of compensation of the delays that occur when converting the satellite signal in the signal ground of reemission.

28. The mode of transmission of the broadcasting program receiver, comprising stages:

reception of satellite signals, which are transmitted using time division or temporal and spatial separation, contain the broadcast program and a combined maximum likelihood; signal ground reemission containing the same broadcast program and transmitted via the ground station reemission;

determining which of the satellite signal combined by the method of maximum likelihood, and ground signal reemission has the best quality;

the choice of the satellite signal combined by the method of maximum likelihood, or signal ground reemission, depending on which one has the best quality of the output signal; and

suppression of switching from the selected signal to another of these satellite signals, if the selection condition depending on the signal quality is not satisfied.

29. The method according to p, wherein the selection condition depending on signal quality corresponds to Brandau threshold value for the frequency of occurrence of erroneous bits for reception of terrestrial signals are then re-emitted.

30. The method according to clause 29, which specified the selected threshold value for the frequency of occurrence of erroneous bits is higher than when you choose the specified ground signal is then re-emitted, and suppress the specified satellite signal combined by the method of maximum likelihood, than when you choose the specified satellite signal combined by the method of maximum likelihood, and suppress the specified ground signal is then re-emitted.

31. The method according to p in which the specified satellite signal combined by the method of maximum likelihood, and in the specified ground signal reemission not use a temporary separation or temporal and spatial partitioning.

32. The method according to p, wherein said step of receiving, designed to receive these satellite signals, further comprises a phase delay of these satellite signals to compensate for delays in the specified ground station re-emission by generating a specified ground signal reemission from the specified satellite signal.

33. The method according to p, wherein said satellite signal is a multiplexed signal with time division and its transform in the specified ground signal is then re-emitted with the use of multiplexing with a temporary split the m/multi-frequency modulation.

34. The method according to p in which the specified delay that occurs in the specified ground station re-emission, corresponds to the processing of the specified satellite signal to convert the specified satellite signal from the specified signal multiplexing time division signal, multiplexed time division/mnogochastotnom modulated signal in a specified ground station reemission.

35. The method according to p, wherein said satellite signal is a signal multiplexed time division/mnogochastotnom modulated signal in the specified ground signal is then re-emitted with the use of multiplexing time division/frequency modulation to generate the specified ground signal is then re-emitted, and the mobile receiver receives and restores as specified signal, multiplexed time division, and the specified signal, multiplexed time division/mnogochastotnom modulated signal.

36. The method according to p which includes the satellite signals are passed via satellite using the first frequency, the specified ground signal reemission transmit using a second frequency through at least one ground station reemission, the specified stage receiving the specified satellite signals and the step of receiving the specified signal ground reemission comply with the admissions section on the first radio wave and the receiving section at the second radio frequency respectively, in at least one of said receivers.

37. The method according to p which includes the satellite signals pass through the first satellite using a first frequency, and these satellite signals pass through the second satellite using a second frequency, the specified ground signal reemission is passed on to a third frequency through at least one ground station reemission, the specified step of receiving these satellite signals is performed by using the first reception section and the second receiving section, operating on a specified first frequency and the second frequency, respectively, and the step of receiving the specified ground signal reemission performed using a third reception section, operating on a specified third frequency, at least one of said receivers.

38. A method of transferring a broadcast program in a receiver, comprising stages

receiving a satellite signal containing the specified broadcast program, and the specified satellite signal is characterized as a single stream of broadcast data containing early channel corresponding to the specified broadcast program, and late channel containing at least a portion of a specified broadcast program, is delayed for a selected period of time prior to the transmission, each of the specified early channel and the late channel has a synchronization code, the specified stream broadcast data encoded parent convolutional encoder working with the selected frequency encoding;

delay specified early channel on the specified selected period of time and

combining the specified late channel with the specified early channel decoder Viterbi maximum likelihood, working with the specified transmission frequency code to restore the specified signal broadcast program without any interruption arising from uncorrelated block when receiving the specified early channel and the late channel.

39. The method according to § 38, wherein said stream of broadcast data contains a broadcast program, designed for mobile reception, and broadcast programs that are designed for stationary reception, and specified early channel contains only the specified broadcast program for mobile reception.

40. The method according to § 38, further containing the step of receiving a terrestrial signal reemission from the ground station and reemission of the second satellite signal containing the specified broadcast program and providing spatial separation in which the specified compared the satellite signal, and each of the specified ground signal is then re-emitted and the specified second satellite signal contains at least the area specified broadcast program and the specified synchronization code, and wherein said step of combining includes the following steps:

the combination of the specified satellite signal, the specified second satellite signal and the terrestrial signal is then re-emitted using the specified code synchronization and

combining to generate the output signal using at least one of the specified satellite signal, the specified second satellite signal and the terrestrial signal is then re-emitted.

41. The method according to p, which indicated earlier specified channel and late channel assign only the specified satellite signal and the specified second satellite signal.

42. The method according to p, further containing the step of accepting a second satellite signal containing the specified broadcast program and providing spatial separation in relation to specified satellite signal, wherein said satellite signal and said second satellite signal passed from different orbital positions in the geostationary orbit.

43. The method according to p, optionally with the containing a series a round of the second satellite signal, containing the specified broadcast program and providing spatial separation in relation to specified satellite signal, wherein said satellite signal and said second satellite signal is passed with three or four different elliptical orbits inclined by approximately 63° in relation to the Earth's equator with a period of one sidereal day.

44. The method is performed in the transmitter for the preparation of the reception by the maximum likelihood method using the receiver decoder Viterbi convolution, containing the following steps:

the use of block coding parent convolution for encoding a broadcast program selected by the frequency encoding and generating parent of output bits in the transmitting station;

generating in the specified transmitting station two streams encoded by the convolution method with a higher frequency by piercing these coded parent of output bits to obtain the first set of punctured encoded bits and the second set of punctured encoded bits;

the purpose of this first set of punctured encoded bits early channel without delay;

the purpose of this second set of punctured encoded bits late channel;

the delay specified later channel for a certain period of time in relation to the specified early channel; and

the transfer of the specified early channel and the late channel, and the specified selected period of time eliminates the correlation with respect to the specified early signal in a mobile receiver, when blocking services due to physical obstacles between the specified mobile receiver and the transmitter, deteriorating the reception in the specified mobile receiver.

45. The method according to item 44, in which the specified frequency coding is R=1/3.

46. The method according to item 45, in which these streams encoded by a convolution with a higher frequency, generate a frequency R=3/4.

47. The method according to item 46, wherein said step of generating includes a step of using 8 out of 18 bits for the coded bits of the specified first broadcast channel and the other 8 of these 18 bits for the specified complementary set, which are the coded bits of the second broadcast channel.

48. The method according to item 44, wherein said early channel and the specified late channel are combined in the receiver to reproduce the specified broadcast program without interruption due to uncorrelated block the specified service.

49. The method according to p in which cardys specified early channel and the late channel contains at least one synchronization code, and optionally containing the following steps:

the delay of the received specified early channel on the specified selected period of time;

correlate the specified synchronization code in each of the received specified early channel and the late channel;

re-regulation of combining the specified early channel in relation to the specified late channel within a fraction of the width of one character bits in the specified broadcast program by combining correlation peaks obtained at this stage of correlation; and

combining bits by the maximum likelihood method specified in the adopted early the channel with the specified late channel Viterbi decoder with soft decision for generating the output signal without neskorrigirovannoe interruption of services due to the occurrence of such physical obstacles.

50. The method according to § 49, wherein said Viterbi decoder with soft decision operates on the specified selected frequency encoding specified parent of the convolution encoder.

51. The method according to § 49, wherein said selected encoding speed is an R=1/3.



 

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