The time alignment supported by the mobile station in cdma communication system

 

The invention relates to a communication system. In the present invention subordinated to the base station reaches the synchronization reference base station via a message transmitted from the mobile station and received by the mobile station in the soft relay transmission between the reference base station and the slave base station. First, the reference base station is measured two-way delay of the signal between the mobile station and the reference base station. When the mobile station captures the signal from the sub base station, it measures and reports the difference between the amount of time it takes the signal from the reference base station before it, and the amount of time it takes for the signal to pass from the sub base station to it. The last thing we need is measurement is subordinate base station, the time difference between the time when it receives the feedback signal of the communication channel between the mobile station and the time when it transmits a signal to the mobile station. Performed a series of calculations on the measured values of time, described here, to determine the time difference in subform b is tanzihi. The technical result consists in providing time synchronization, when part of the network is able to accept a centralized chronology signal to achieve synchronization from him, and some base stations are not able to take it. 2 s and 5 C.p. f-crystals, 9 Il.

I. technical Field,

The present invention relates to a communication system. More specifically, the present invention relates to a new and improved method and apparatus for synchronization of a base station by means of signals transmitted from the mobile station, which is connected in parallel with synchronized base station.

II. Prior art

The method of modulation multiple access code division multiple access (CDMA) is only one of several technologies to support communication, in which there are a large number of system users. Although there are other methods, such as multiple access with time division multiplexing (TDMA), multiple access frequency division multiple access (FDMA), and AM modulation schemes such as single side-band with the compression/expansion of the amplitude (ACSSB), CDMA has nacinajuscego access described in U.S. patent No. 4901307, entitled "communication System multiple access with transmission of signals over a wide range using satellite or terrestrial repeaters", and U.S. patent No. 5103459, entitled "System and method for generating waveforms of the signal in the cell phone CDMA system", both of which transferred to the assignee of the present invention and is incorporated here by reference. Method for providing mobile communications CDMA has been standardized in the United States communications industry Association standard TIA/EIA/IS-95-A, entitled "Standard compatibility stations on the basis of the mobile stations for dual-mode wideband cellular systems with signal transmission in a wide range, which is referred to here as IS-95.

In the just mentioned patent describes a method of multiple access, in which a large number of users of mobile stations, each of which includes a transceiver, communicate through satellite repeaters or terrestrial base stations (also known as cellular base stations or cell sites), using the communication signals multiple access code division multiple access (CDMA) signal transmission in a wide range. When using CDMA frequencies of the users in the system. Using the CDMA method gives a significantly higher spectral efficiency than can be achieved using other multiple access methods.

Method for the simultaneous demodulation of data that pass through different propagation paths from one base station, and for the simultaneous demodulation of data redundantly supplied from more than one base station is described in U.S. patent No. 5109390 (patent `390), entitled "Receiver explode in the CDMA cellular system", submitted to the assignee of the present invention and is incorporated here by reference. In patent `390 separately demodulated signals are combined to provide an estimate of the transmitted data, which have greater reliability than the data demodulated any one tract or from any one base station.

Relay transmission can be divided into two categories - hard transfer and soft transfer. In hard handover, when the mobile station leaves the source base station and enters the realm of the base station of the destination, the mobile station terminates its communication channel with the source base station and then establishes a new communication channel with the base station of item unique destination before the termination of the communication channel from the source base station. Therefore, when soft relay transmission, the mobile station within a certain period of time unnecessarily supports communication with the source base station and the base station of the destination.

When soft the transmission probability of the termination of the conversation is much less than with hard gear. In addition, when the mobile station moves near the border of the service area of the base station, it can perform repeated requests for relay transmission in response to small changes in the transmission medium. This problem, called ping-pong switching, it also significantly reduces soft pass. The implementation of soft relay transmission described in U.S. patent No. 5101501, entitled "Method and system for providing a soft relay transmission when connected to cell phone CDMA system", submitted to the assignee of the present invention and is incorporated here by reference.

An advanced technique soft relay transmission described in U.S. patent No. 5267261, entitled "Soft relay transmission supported by the mobile station in the CDMA cellular system", submitted to the assignee of the present invention and is included here as ssylbnyh" signals, transmitted by each base station and a mobile station. These measure the level of the pilot signal help in the process of soft relay transmission by facilitating the identification of suitable base stations that are candidates for relay transmission.

Candidates from base stations can be divided into four groups. The first group, called the Active set contains a base station, which currently are in communication with the mobile station. The second group, called the Set of candidates contains a base station, the signals from which were identified as having a sufficient level to be used by the mobile station, but at the current time they are not used. Base stations are added to the Set of candidates, when they measured the energy of the pilot signal exceeds the given threshold T. the Third group has a set of base stations that are located near the mobile station (and which are not included in the Active set or the Set of candidates). And the fourth group is the Rest of the kit, which consists of all other base stations.

In IS-95 base station candidate differs phase shift psevdochumoy (PN) sequence of the pilot channel. When the mobile station ASU is the situation of correlation, in which the filtered received signal is correlated to the set of hypotheses offset PSH. Method and device for performing the correlation operation are described in detail in co-pending application for U.S. patent No. 08/687694 filed July 26, 1996, entitled "Method and apparatus for search and seizure in the CDMA communication system", which is passed to the assignee of the present invention and is incorporated here by reference.

The propagation delay between the base station and the mobile station is unknown. This unknown delay creates an unknown shift in the PN codes. The search process attempts to identify an unknown shift in the PN codes. To accomplish this, the mobile station shifts in time, the output signal generator SG device code of its search. The search range of the shift is called the search window. The search window is centered around the hypothesis PSH of the shift. The base station transmits to the mobile station a message indicating PSH shifts of the pilot signals of base stations that are in physical proximity. The mobile station will center your search box near the hypotheses PSH of the shift.

A suitable size of the search window depends on several factors, including the priority of the pilot signal, b is the CDMA standards (IS-95) determine the three parameters of the search window. Search for pilot signals in the Active set and the Set of candidates is controlled by the Search Box. The pilot signals of the neighbor set are searched for in the "N" and the pilot signals to the Rest of the set is searched in the "R". The window size of the device search is shown in the table, where the basic premise is equal to 1/1, 2288 MHz.

The window size is optimally chosen by the ratio between the speed of the search and the probability of skipping a strong tract that lies outside the search window.

The base station transmits to the mobile station a message that defines a hypothesis PSH that the mobile station should seek relative to its offset PSH. For example, the source base station may instruct the mobile station to search for a pilot signal 128 PSH elementary parcels ahead of her PSH of the shift. The mobile station in response sets its demodulator device search 128 elementary parcels ahead in the output of the elementary cycle and searches for the pilot signal, using a search window centered around a particular offset. When the mobile station has received the command to search the hypothesis PSH, to determine the resources available to perform the relay transmission, the critical is the fact that PSH is the t critical value near the borders of the service area of the base station, because of delays in completing the necessary searches can lead to interruption of the conversation.

In CDMA systems in the United States this synchronization of the base station is achieved by providing each base station receiver, a Global Satellite Positioning (GPS). However, there are cases when the base station cannot receive the GPS signal. For example, in the subway tunnels, the GPS signals are reduced to a degree that prevents their use for time synchronization of base stations or mikrobasic stations. The present invention provides a method and system for providing time synchronization in these circumstances, where part of the network is able to accept a centralized chronology signal to achieve synchronization from him, and some base stations are not able to accept centralized chronology signal.

Disclosure of the INVENTION

The present invention is a new and improved method and apparatus for time synchronization of the base station that is not able to accept centralized chronology signal in the network, where some of the base stations capable of receiving centralized chronology signal. The anchor base station has the temporal example of the execution of the reference base station is synchronized, using the receiver for the global satellite positioning (GPS). The subordinate base station is not able to synchronize, because, for example, inability to make centralized chronology signal.

In the present invention subordinated to the base station reaches the synchronization reference base station via a message transmitted from the mobile station and received by the mobile station in the soft relay transmission between the reference base station and the slave base station. First, the reference base station measures the two-way delay of the signal between the mobile station and the reference base station. Then subordinated to the base station looks up until it is flush with the signal transmitted by the mobile station, the call signal of the reverse link. In response to receiving the feedback signal of the communication channel subordinated to the base station adjusts its timing to the mobile station could capture its signal, called signal direct communication channel. This step may not be needed if the accuracy of timing in slave base station is not rough.

When the mobile station receives the signal La of the signal from the reference base station before it, and the amount of time it takes for the signal to pass from the sub base station to it. The last dimension that is required is the measurement of the subordinate base station, the time difference between the time when she accepted the position feedback signal of the communication channel between the mobile station and the time when she gave the signal to the mobile station.

Performed a series of calculations on the measured values described here in detail, to determine the time difference in the subordinate base station, and adjusts the timing of the subordinate base station in accordance with them. It should be noted that all the measurements performed during the normal operation of the communication system of the CDMA IS-95.

BRIEF DESCRIPTION of DRAWINGS

Further features, objectives and advantages of the present invention will become clearer from the detailed description below, with reference to the drawings, in which identical reference positions respectively shown in all drawings and in which:

Fig.1 is a block diagram illustrating a network configuration of a wireless system that contains the reference base station and a subordinate base station;

Fig.2 is a schematic, Il the station and the corresponding time intervals;

Fig.3 is a block diagram illustrating a synchronization method of a base station that is unable to accept centralized chronology signal;

Fig.4 is a block diagram of the mobile station according to the present invention; and

Fig.5 is a block diagram of a device search in the mobile station according to the present invention; and

Fig.6 is a block diagram of the modulator of the channel traffic of the mobile station according to the present invention; and

Fig.7 is a block diagram of a base station according to the present invention; and

Fig.8 is a block diagram of a transmission system of a base station according to the present invention and

Fig.9 is a block diagram of a reception system of a base station according to the present invention.

A DETAILED DESCRIPTION of the PREFERRED embodiments

I. Overview of the calculation error of timing

Referring to Fig.1, the mobile station 60 is in communication with the base station 62, as it is about within the service area defined by the boundary 61 of the service area of the base station. The base station 62 is synchronized with the rest of the network via a Central system of timing, such as a global positioning system (GPS). In protivopolojno base station forwards the calls from the PSTN to the base station 62 or 64 by means of a T1 line or other means. In addition, the synchronization frequency is supplied to the base station 64 through line T1.

For short periods of time and frequency synchronization can be achieved with an acceptable degree of accuracy through line T1 ways, well known in the prior art. However, in these schemes to provide frequency information there are total failures. These failures lead to errors of timing, which can be adjusted by use of the present invention. Given the relation between phase and frequency, irregular correction phase according to the present invention will allow the use of less accurate frequency source when you need it.

In Fig.2 shows the illustration of the transmission and the corresponding time intervals used for synchronization of timing slave base station 64 with synchronized timing of the reference base station 62. The signal path 500 illustrates transmitting a direct communication channel from the reference base station 62 to the mobile station 60. The time interval in which the transfer means1. In the mobile station 60 the beginning of the transmission data block to the reverse channel agreed upon lie included in the equipment, designed in accordance with this, so the methods and devices for performing this agreement are well known in the prior art.

Transmission 502 shows the transmission of a data block reverse communication channel from the mobile station 60 to the reference base station 62. The time required for a signal 500 to go from the base station 62 to the mobile station 60 (1), is equal to the time required for the signal 502 to be transmitted from the base station 62 to the mobile station 60 (also1). Since the base station 62 knows the time when she gave the signal 500, and knows the time when she received signal 502, the base station 62 can calculate the time two-way delay signal (RTD1), which is the first value necessary to calculate the error in time (`about-about).

The signal path 504 is a signal transmission reverse communication channel from the mobile station 60, going the other way distribution to slave base station 64. The time required by the signal 504 to be transmitted from the mobile station 60 to the slave base station 64, denoted by2. Time is the existing signal 506 direct communication channel transmitted from the base station 64 to the mobile station 60, equal2. In addition, the base station 64 may measure a time difference between when she accepted the position feedback signal of the communication channel between the mobile station 60, and the time when she gave his signal direct communication channel to the mobile station 60. This time difference RTD marked2. The knowledge of these times allows us to calculate the error of the time (`o-o). The method of calculating the error of the time`odescribed below.

First of figs.2 one can observe that the

After the operation in equation (1) and (2), we obtain the following:

To simplify writing, we denote the new variable RTD2as

It is evident from Fig.2 you can see that

Therefore,

RTD2=22-T.

By substitution, one can see that the error time (T`o-To) p is p>

Since the base station 64 knows the magnitude of his error of timing (T`o-To), it adjusts its timing to synchronize with the timing of the base station 62. These measurements are prone to errors, so that in a preferred embodiment, redundantly performed many measurements to ensure the accuracy of correction of timing.

Now describe the method and the device for measuring each in equation (12) units.

II. Measurement of two-way delay signal (RTD1)

In Fig.3 shows a block diagram illustrating the method according to the present invention to synchronize the slave base station 64 in time with the reference base station 62. In step 300, the method of synchronization begins with the mobile station 60, which is in communication with the reference base station 62 and in the range that allows communication with the slave base station 64. In step 302, the measured time two-way delay signal (RTD1) required for a signal to pass from the base station 62 to the mobile station 60 and back from the mobile stanziola 60, with the boundaries of the data blocks transmitted by the mobile station 60. Method and device for ensuring this alignment are well known in the prior art. Thus, the two-way delay signal (RTD1) is measured as the difference in time between the beginning of the data blocks transferred to the reference base station 62, and the beginning of the data blocks received reference base station 62 from the mobile station 60.

Referring to Fig.4, the data blocks direct communication channel from the reference base station 62 are received by the antenna 2 and fed through duplexer (antenna switch) 3 to receiver (RCVR) 4. The receiver 4 converts with decreasing frequency, filters and amplifies the received signal and delivers it to the device 50 and demodulators traffic DEMODS) 54. Device 50 searches for a pilot channel in accordance with the list of neighboring stations, transmitted reference base station 62. A list of nearby stations is transmitted as alarm data on the channel traffic from the reference base station 62. The signal indicating the beginning of the received data blocks from the reference base station 62, is fed to the control processor 55. Control processor 55 generates and sends a signal alignment time to the modulator 58 traffic, which is odbijenou station 60.

Blocks of data from a user of the mobile station 60 is served to the modulator 58 traffic, which in response to the clock signal from the control processor 55 is aligned to the time the data blocks are transmitted through a transmitter (TMTR) 56, with blocks of data, adopted by the mobile station 60 from the reference base station 62. Data blocks reverse communication channel is converted with increasing frequency, are filtered and amplified by transmitter 56 and is fed through the duplexer 3 for transmission via the antenna 2.

III. Capture mobile station sub-base station

Fig.6 illustrates the modulator 58 traffic channels of the mobile station 60. Blocks of data are served to the formatter 200 blocks of data. In the illustrated embodiment, the formatter 200 blocks of data generates and attaches the set control bit cyclic redundancy code (CRC) and generates a set bit late. In the illustrated embodiment, the formatter 200 blocks of data follows the format Protocol data unit, standardized in IS-95 and is described in detail in U.S. patent No. 5600754, entitled "Method and system for arrangement of vocoder data for the masking of failures induced by the transmission channel, which is transferred to the assignee of the present invention for error correction and detection. In the illustrated embodiment, the encoder 202 is a convolutional encoder. The encoded data symbols are served to the multiplier 204, which changes the order of symbols in accordance with a specified format interleave. Characters with the measured order is served to the Converter 206 Walsh. In the illustrated embodiment, the transducer 206 Walsh takes eight coded symbols and converts this set of characters in the sequence of the 64 Walsh elementary parcels. Characters Walsh served by the tool 208 extension that extends the characters Walsh in accordance with the long code of the extension. The generator 210 long PN code generates pseudotumour (PN) sequence, which expands the data and separates the data from the back channel data transmitted from other mobile stations nearby.

In the illustrated embodiment, the data is transmitted in accordance with the format modulation quadrature phase shift keying (QPSK), in which the channels I and Q are expanded in accordance with the short PN sequence. Extended data served to the means of extension 214 and 216, which performs the second expansion operation on the data according to the acting

In step 304 the subordinate base station 64 receives the signal of the reverse channel transmitted by the mobile station 60. The controller 66 base station sends a signal to the slave base station 64, showing the offset of the PN code, which the mobile station 62 uses to expand its reverse signal of the communication channel. In response to this signal from the controller 66 base stations subordinate to the base station 64 searches for the mobile station 60, tsentrirovannoi about shift PSH indicated by the signal from the controller 66 to the base station.

In the illustrated embodiment, the Bank slave base station 64 loads the signal generator 106 PN long code and generators 108 and 110 PN short code of the device search (shown in Fig.9) in accordance with the signal from the controller 66 to the base station. The operation of the device search slave base station 64 is described in detail hereafter.

Fig.7 illustrates the device slave base station 64. In slave base station 64 signal is received from the controller 66 of the base station, showing PSH mobile station 60. This message is supplied to the control processor 100. In response, the control processor 100 calculates the search range window, t is the claim 101, and in response to these parameters subordinate base station 64 searches for the signal transmitted by the mobile station 60. The signal passed by the antenna 102 of the slave base station 64, is fed to the receiver 104, which converts with decreasing frequency, filters and amplifies the received signal and delivers it to the device 101. In addition, the received signal is fed to the demodulators 105 traffic that demodulated data of the reverse traffic channel and serves the data to the controller 66 to the base station. The controller 66 of the base station, in turn, submits them to the public switched telephone network of General use (PSTN).

Fig.9 illustrates in more detail the device 101. The demodulation signal of the backward communication channel is described in detail in concurrently pending application for U.S. patent No. 08/372632, filed January 13, 1995, entitled "Architecture of the demodulator mobile node for communication systems, multiple access with transmission of signals over a wide range and jointly pending application for U.S. patent No. 08/316.177, filed September 30, 1994, entitled "Multi-processor search for communication systems, multiple access with transmission of signals over a wide range, both of which transferred pravopriemnitsey processor 100 from the controller 66 to the base station. In response to the evaluation of PN offsets filed by controller 66 base station control processor 100 generates an initial hypothesis of the long PN sequence and the initial hypothesis of short PN sequences to search that should be performed slave base station 64. In the illustrated embodiment, the data Bank control processor 100 loads the shift registers PN generators 106, 108 and 110.

The signal passed by the antenna 102, is converted with decreasing frequency, is filtered, amplified and fed to the correlator 116. The correlator 116 correlates the received signal to the combined hypotheses of long and short PN sequences. In the illustrated embodiment, the hypothesis PN sequence is generated by multiplying the short PN hypotheses generated by the PN generators 108 and 110, the long PN sequence generated by PN generator 106. One of the United hypotheses PN sequence is used to compress the channel I, and the other is used to compress the channel Q of the received QPSK signal.

Two PSH compressed signal serves to processors for fast Hadamard transform (BIA) (FHT) 118 and 120. The construction and operation of processors for fast Hadamard transform on the military "Method and apparatus for performing a fast Hadamard transform", which is passed to the assignee of the present invention and is incorporated here by reference. The processor of the unit 118 and 120 correlate compressed signals with all possible characters Walsh to create a matrix of the resulting amplitudes for the tool 122 calculate the energy (I2+ Q2). The tool 122 calculation of energy calculates the energy of the elements of the matrix of amplitudes and delivers the amount of energy to the detector 124 maximum, which selects the maximum correlation energy. Energy maximum correlation serves to drive 126, which accumulates energy for many characters Walsh, and on the basis of this accumulated energy values to determine whether the mobile station 60 to be captured in this PN offset.

IV. Adjust the initial timing of the subordinate base station

When the mobile station 60 is captured, then in block 306 the subordinate base station 64 adjusts its timing to the mobile station 60 was able to successfully receive the transmission of the direct channel. The subordinate base station 64 calculates the adjustment start timing by determining the difference between the PN offset, in which she captured the ring-back channel communication is about communication channel from the mobile station 60. Using this differential PN offsets, the subordinate base station 64 adjusts the timing of its pilot signal so that when the mobile station 60 is looking for its pilot signal, it will be inside the search window of the mobile station 60.

V. Capturing the subordinate base station by the mobile station

When searching for the signal of the mobile station slave base station 64, you must have some indication of time. In a preferred embodiment, the time uncertainty slave base station 64 is set to 1 MS or less 1 MS through alternative schema synchronization. There are schemes that allow the slave base station 64, which are unable to receive the GPS signal, to keep time with a lower level of accuracy. One possible way to obtain the degree of initial synchronization is to manually set the time slave base station 64 at certain intervals. The second method consists of determining the time using WWV receiver, which is well known in the prior art. Unlike GPS, WWV centralized time signal is transmitted at a very low frequency and are able to penetrate into the tunnels, and subway. Oh and CDMA.

In the illustrated embodiment, the subordinate base station 64 adjusts its timing in accordance with the assumption that the mobile station 60 is located directly adjacent to the slave base station 64. Thus, the initial adjustment of the synchronization with the assumption that there will be no propagation delay between slave station 64 and the mobile station 60. After that, the subordinate base station 64 adjusts its generators 72 and 74 PN sequences forward in time, which takes into account more and more time propagation delay between slave base station 64 and the mobile station 60. When the mobile station 60 has captured the pilot channel of the slave base station 64, using conventional procedures can be performed final adjustment of timing for slave base station 64 in accordance with the above calculations.

As is known in the prior art and as standardized in IS-95, the pilot channels of different base stations differ from each other by the phase PN generators. The reference base station 62 instructs the mobile station 60 to look for a subordinate base station 64 through the list with McInerney base station 64 can be captured on the offset of the PN phase, which is described relative to a received PN offset of the reference base station 62. This message is demodulated and decoded by the demodulator 54 traffic and is served by the device 50. In response, the device 50 searches, centered on the offset of the PN phase about PSH phase specified in the signal from the reference base station 62.

The pilot signal is usually generated by a shift register with linear feedback, which is described in detail in the aforementioned patents. In order to capture the pilot signal from the slave base station 64, the mobile station 60 must be synchronized to the received signals from the slave base station 64 as phaseand frequency. The purpose of device search is to find the phase of a received signal. As described previously, a relatively accurate frequency synchronization can be fed to the slave base station 64 through channel T1 connection from the base station controller 66, as is known in the prior art. The way in which the mobile station determines the phase of the received signal, is to test a set of hypotheses phase, called the search window, and determining the beach on the station. The wide signal spectrum is received in the antenna 2. The purpose of the device is increased synchronization between pseudocumene (PN) sequences generated by the PN generator sequences 20, and the received signal a wide range, which is extended identical PN sequences of unknown phase, transferred to the slave base station 64. In the illustrated embodiment, the generator 76 of the pilot signal (Fig.7), and PN generator 20 are shift registers maximum length that generate the PN sequence code for expansion and contraction of the pilot signals, respectively. Thus, the operation of obtaining synchronization between the codes used to compress the received pilot signal and the PN code of the extension of the received pilot signal includes determining the time offset of the shift register.

Signal a wide range served by the antenna 2 to the receiver 4. The receiver 4 converts with decreasing frequency, filters, amplifies the signal and sends a signal to the compression element 6. Element 6 compression multiplies the received signal PN code generated by PN generator 20. Due to the random noise-like nature of the PN codes, the product of the PN code and the received signal must be in the bias to the PN generator 20. Hypothesis offset is determined in accordance with the signal transmitted to the mobile station 60 reference base station 62. In the illustrated embodiment, the received signal is modulated using quadrature phase shift keying (QPSK), so that PN generator 20 delivers the PN sequence for modulation component I and a separate sequence for the component Q modulation element 6 compression. Element 6 compression multiplies the PN sequence to its corresponding component modulation and takes the two pieces of output components to a coherent drives 8 and 10.

Coherent drives 8 and 10 summarize the work on the length of the sequence works. Coherent drives 8 and 10 respond to signals from the controller 18 of the device search for reinstalling, fixing and installation period summation. The amount of works submitted from the adders 8 and 10 to the vehicle 12 squaring. The tool 12 squared squares each of the sums and sums them together.

The sum of squares is served by the tool 12 squaring it to the non-coherent combiner 14. Non-coherent integrator 14 determines the amount of energy from the output means 12 squaring. Incoherent, however, the tion and receiving hours mobile station, and helps in the detection statistics in the fading environment. Incoherent drive 14 sends a signal energy to the tool 16 comparisons. The tool 16 comparison compares the energy value with predetermined thresholds, filed by the tool 18 of the controller device search. The results of each comparison are then fed back to the controller 18 of the device search. The results submitted back to the controller 18 of the device search, include both energy correlation, and PN offset that is obtained in the measurement.

In the present invention, the controller 18 of the device search gives PN phase at which it is synchronized to the base station 64. This offset is used to calculate the errors of the time, as described hereafter.

In the illustrated embodiment, when the mobile station 60 captures a subordinate base station 64, it calculates the difference between the time it took the signal from the slave base station 64, and the time when it received the signal from the reference base station 62. This value is fed to the generator 52 messages, which generates a message indicating the magnitude of the difference. The message is transmitted as alarm data on a reverse channel to the supporting base hundred

VI. The measurement of the delay between the signal transmission direct communication channel from the slave base station and the reception signal of the reverse link in a subordinate base station

In step 311 the subordinate base station 64 measures the difference in time between when it receives the signal of the reverse communication channel from the mobile station 60 (T2), and the time when it transmits its signal direct communication channel to the mobile station 60 (T1). The subordinate base station 64 writes the PN offset in time when it transmits its signal to the direct communication channel, and after the detection signal of the reverse communication channel from the mobile station 60 calculates the time difference RTD2. In the illustrated embodiment, this calculated time difference is served slave base station 64 to the base station controller 66 and the calculation of the adjustment of timing is performed in the (controller) base station 66. An experienced specialist will be clear that the present invention can be easily extended to the case in which the calculation is performed in the base stations or mobile stations.

VII. Adjusting the timing of the subordinate base station

USB circuits which adjust the timing to the slave base station 64. Referring again to Fig. 7, the adjustment signal of timing taken slave base station 64 in the control processor 100. Control processor 100 generates and supplies a control signal to the CPU 99 adjust the timing. The processor 99 adjustment synchronization generates a signal that changes the time source 98 synchronization to the extent specified in the signal from the controller 66 to the base station.

Claims

1. The way time synchronization slave base station with the reference base station, comprising stages, which are measured on the reference base station delay on a bilateral signal flow when transmitting at least one signal from the reference base station to the mobile station and back from the mobile station on the supporting base station measured at the mobile station a first time difference between a time of reception at the mobile station signal slave base station and the time of reception at the mobile station the signal of the reference base station, measure the sub base station, a second time difference between the time of admission to the subordinate base station of the mobile signal is recchi time on the basis of the results of measurement delay for a two-state signal of the first difference in time and the second difference in time moreover, the correction time is determined by the synchronization error between the slave base station and the reference base station, the synchronization error equal to (RTD1+T-RTD2)/2, where RTD1- delay on a bilateral signal flow when transmitting at least one signal from the reference base station to the mobile station from the mobile station to the reference base station,T is the time difference between the time of reception at the mobile station signal slave base station and the time of reception at the mobile station the signal of the reference base station and RTD2- delay on a bilateral signal flow when transmitting at least one signal between the subordinate base station and mobile station, and the delay for a two-state signal is determined by the time of admission to the subordinate base station signal of a mobile station and a transmission signal from the sub base station to the mobile station.

2. The method according to p. 1, additionally containing a stage at which carry out the transfer of the mobile station from the reference base station to the subordinate base stations station for its approval of the synchronization reference base station, if the value of the adjustment time exceeds a specified amount.

4. The method according to p. 3, additionally containing a phase in which before to calculate the adjustment synchronization, measurement is carried out repeatedly, ignoring the distorted dimension.

5. The method according to p. 4, optionally containing phase in which when performing calculations adjust the timing using the averaged result of the repeated measurements.

6. The way time synchronization slave base station with the reference base station, comprising stages, which are measured on the reference base station delay on a bilateral signal flow when transmitting at least one signal from the reference base station to the mobile station from the mobile station to the reference base station, get on the subordinate base station signal to the mobile station, adjust the reference signal is time for the subordinate base station to mobile station can receive the signal of the subordinate base station, receiving at the mobile station the signal of the subordinate base station, measured at the mobile station a first time difference between a time of reception at the mobile station the signal porcine the difference in time of the reference base station and a subordinate base station, measure the sub base station, a delay on a bilateral signal flow when transmitting at least one signal between the subordinate base station and mobile station, and delay for two-way signal flow is determined by the time of admission to the subordinate base station signal of a mobile station and a transmission signal from the sub base station to the mobile station, calculates the base station controller the correction time for the subordinate base station based on the measurement results, and the correction time is determined by the synchronization error between the slave base station and the reference base station, when this synchronization error is equal to (RTD1+T-RTD2)/2, where RTD1- delay on a bilateral signal flow when transmitting at least one signal from the reference base station to the mobile station from the mobile station to the reference base station,T is the time difference between the time of reception at the mobile station signal slave base station and the time of reception at the mobile station the signal of the reference base station to the subordinate base station and mobile station, moreover, the delay on a bilateral signal flow is determined by the time of admission to the subordinate base station signal of a mobile station and a transmission signal from the sub base station to the mobile station.

7. The method according to p. 6, further containing a stage at which govern the synchronization of the slave base station in accordance with the synchronization reference base station, if the value of the correction time exceeds a specified amount.

 

Same patents:

The invention relates to a digital radio network decameter range with packet transmission of information, functioning in the conditions of destabilizing factors

The invention relates to cellular communication systems

The invention relates to mobile communication

The invention relates to cellular telephone systems

The invention relates to mobile communications systems

The invention relates to the field of authentication objects

The invention relates to a device for radio communication, in particular to a method and device for implementing the method synchronize the communication is divided into frames of data across the asynchronous base station in the cellular system

The invention relates to communication technology and can be used in mobile communication systems

The invention relates to a method of controlling the transmission associated with temperature, in Radiocommunication systems

The invention relates to the field of radio communications and computer engineering and can be used to transfer information to the computer network radio

The invention relates to automatic control systems for organizing links in the trunk interfaces for signaling code Manchester-2"

The invention relates to the field of radio and can be used in communication systems with broadband signals

The invention relates to the field of telecommunications and computer technology, in particular to methods and devices for data transmission in the computer network by radio with pseudorandom change the operating frequency

The invention relates to the field of discrete information transmission and can be used in radio channels to transmit information in space and terrestrial communication systems using pseudonoise signals

The invention relates to radio engineering

The invention relates to radio communication devices

FIELD: radio engineering; construction of radio communication, radio navigation, and control systems using broadband signals.

SUBSTANCE: proposed device depends for its operation on comparison of read-out signal with two thresholds, probability of exceeding these thresholds being enhanced during search interval with the result that search is continued. This broadband signal search device has linear part 1, matched filter 2, clock generator 19, channel selection control unit 13, inverter 12, fourth adder 15, two detectors 8, 17, two threshold comparison units 9, 18, NOT gates 16, as well as AND gate 14. Matched filter has pre-filter 3, delay line 4, n attenuators, n phase shifters, and three adders 7, 10, 11.

EFFECT: enhanced noise immunity under structural noise impact.

1 cl, 3 dwg

Up!