The method of acceptance of multipath signals (variants) and a device of the reception and transmission of signals, code-division multiplexing (options)

 

(57) Abstract:

The inventive method of transmission / reception of multipath signals in a cellular radio system with code division of channels, namely, that the mobile station form L spatially dispersed channels of reception signal in each channel are searching rays of the signal at the interval of uncertainty for the delay. M detected rays emit N M rays, the highest energy level, and carry out their demodulation. The device for implementing the method comprises the antenna, the diplexer, the analog receiver, the receiver search, L receivers, data, control processor, the power combining signals from the decoder, the block of user data, the modulator of the transmitter, the power control of the transmitter, the power amplifier of the transmitter. Thus formed L in a similar and parallel branches of the reception signal, in each of which the antenna is made spatially oriented with a narrow radiation pattern. Put two of the switching unit, the first is to select the maximum of information signals from receivers of data, the second is to connect the transmitter output to the channel that is taken is to search on the interval of uncertainty for the delay and tracking in each of the L space-separated channels of the reception signal. 5 C. and 1 C.p. f-crystals, 8 ill.

The invention relates to radio engineering, more specifically to methods and devices of the transmission / reception of multipath signals, and can be used in digital radio communications, code division channels and other areas.

Art

The most promising for mobile and personal communications in the present system are multiple access code division multiple access (CDMA). As the media used in the CDMA pseudonoise signals (wideband signals, PSS). The wider the range of broadband signals and freer from intentional interference corresponding to the transmission frequency band, the more noise-and capacious number of subscribers of the communication system can be created on its basis. These requirements satisfy the bandwidth in the range of not lower than UHF. Therefore, cellular systems with code division multiplexing (CDMA) focused on the frequency bands (815-870) MHz, 1800 MHz, 1900 MHz and above, up to the optical range. The propagation of these ranges in big cities (thick, solid and high-rise buildings streets, transport interchanges in the form of flyovers, tunnels and so on ), as well as outside the cities in Herencia of these rays. Result in local fading, until the complete loss of signals in anti-phase addition of the rays and the gain of the signal when the common-mode summation. For this reason, creating areas of difficulty and coverage. In mobile communication systems due to the relative movement of the base station and the mobile station additionally occurs to the unsteadiness of the parameters of the input signal due to varying combinations of rays received by the mobile and base stations having different for each beam Doppler shifts of the carrier frequency broadband signals, and due to the non-stationary properties of the radio channel.

In such a complex dynamic interference pattern when processing input signal fading occurs with a frequency equal to the algebraic sum of the Doppler shifts of the carrier frequencies in the incoming rays (William K. Lee. The technique of mobile communication systems. M., "Radio communication, 1985, Chapter 1, 3-7) [1].

Known "Method and device for signal formation in cellular communication systems" (U.S. patent N 5309474 IPC5H 04 L 27/30) [2].

The method consists in the fact that in the forward direction to the mobile station form L spatially dispersed delay, from M the detected rays emit N M rays, the highest energy level, exercise their demodulation, highlight information, and in the opposite direction transmit user information.

The device of the reception and transmission of signals to the mobile station in the CDMA system includes an antenna, a diplexer, an analog receiver, the receiver searches and L receivers of the data block Association signals and the decoder, the block of user data, the modulator of the transmitter, the power control of the transmitter power amplifier of the transmitter.

The disadvantage of this method of transmission / reception of multipath signals and device for its implementation [2] is a low immunity, leading to reduced system capacity.

The closest technical solution to the claimed method and device for its realization is the invention (U.S. patent N 5109390 IPC5H 04 L 27/30 "Diversity reception in a cellular radiotelephone system" [3].

Device-prototype [3] in accordance with Fig. 1 includes an antenna 1 for receiving the broadband signal from the base station and transmit the broadband signal from the mobile station to the base station.

The diplexer 2 provides full-duplex operation mode of the mobile stations is amnic 3 receives RF signals from the diplexer 2 for amplification and conversion into a signal of a low-frequency intermediate frequency, and performs a control function for adjusting the transmitter power of the mobile station, produces an analog control signal, which transmits the power control of the transmitter 10.

Receiver search 4 continuously scans the time interval uncertainties in the vicinity of the detected temporary position (delay) of the primary pilot signal received from the base station, and other rays of this signal. In accordance with the output signal from the control processor 6 receiver search 4 measures the power of any of the received signals with delays, non-rated, and transmits the measurement results to the control processor 6.

The data receivers 5-1 and 5-2 handle two of the strongest signal found by the receiver search 4, and generates the processed signal in the unit of Association signals and the decoder 7.

Control processor 6 in accordance with information received manages data receivers 5-1 and 5-2, the receiver search 4, the modulator of the transmitter 9 and the power control of the transmitter 10. Together with the receiver search 4 control processor 6 organizes continuous search of the base station signal, forming a pseudo-random sequence with the corresponding time delays. Found a variety of responses highlights the two largest the second processor in conjunction with the data receivers 5-1 and 5-2 provides processing found two largest signals and carries out tracking the delays of these signals. Control processor 6 in accordance with the information received from the data receivers 5-1 and 5-2 generates the control signal for the power control of the transmitter 10 and the required encoding signals for the modulator of the transmitter.

The block Association signals and the decoder 7 summarizes the two signals from the data receivers 5-1 and 5-2 with delay and decodes the received total signal. The output signal of this block is fed to the block user data 8.

The block user data 8 converts the decoded digital information signal into a form suitable for user devices (Fax, display - digital form, microphone - analog). Converts an informational message for the user in digital form to the modulator of the transmitter.

The modulator of the transmitter 9 generates a signal for the transmitter of the mobile station (encoding Walsh, I, Q, L - pseudo-random sequence, etc.).

In the power control of the transmitter 10, the signal of the intermediate frequency modulated signal from the modulator of the transmitter 9. The result is a pseudo-random signal at the intermediate frequency, which is governed by the power control signals from analog priemnikami 11 input broadband intermediate frequency signal with the power control of the transmitter is converted into the RF signal by using the frequency synthesizer of the transmitter of the mobile station, increases power to the desired level and is fed to the diplexer 2.

The disadvantage of this method of transmission / reception of multipath signals and device for its implementation [3] is low immunity, leading to reduced system capacity.

In mobile communication systems with analog signals fading occurs due to multiple reflections of the signal transmitter only from close objects [1]. These objects are located inside the circle in the center of which is the mobile station. The radius of the circle is several tens of meters.

To improve noise immunity in conditions of multipath need to receive several components of the same broadband signal coming from different directions. These reflected signals can be divided into two groups. The first group of components of the broadband signals coming from different directions with delays longer than the duration of a chip, modulating a pseudo-random sequencei. The second group of components of the broadband signals with delays lessi. The presence of such groups is confirmed by experimental results [3], from which it follows that delays powerful componency allow the most powerful and posted more thanicomponents of the broadband signal to be processed separately from each other, since they vzaimokreditovanie function is equal to 0, i.e., possible temporary selection of such components. For a broadband signal with a delay not exceedingiwith respect to the selected Autonomous rays (group signal), vzaimokreditovanie functions are not equal to zero. The signals are within an aperture time discriminator, distort discriminatory characteristic block tracking signal delay and are perceived as a group signal. As a result of this reduced the effectiveness of the tracking delay of the signal, and can occur disruption tracking. Moreover, typical conditions, when the group signal is a broadband signal is generated from signals coming from different directions and having a relative delay of no more than i. Therefore, in group a broadband signal is further possible fading, the deeper, the more different one from another direction-of-arrival of each beam group at the receiver input.

Thus, the processing system can be represented in the following form: there are several of the most intense beams, spaced drogerie thani. This structure (composition) is an Autonomous group signal and can be considered independently from the others.

Consider the possible values of fading in the group signal.

It is known that the geometric place of the points for which the sum of distances from two given points is a constant, is an ellipse (I. N. Bronstein, K. A. Semendjajew. Handbook of mathematics. M. "Science". 1965, S. 206) [4].

Using this definition and vzaimokreditovanie properties of the wideband signal, it is possible to build a area that can receive the reflected rays with delays in this area vzaimoobratima function is not equal to zero, all broadband signals such delays involved in the formation of fading, outside this area vzaimoobratima function is equal to zero, and all such broadband signals on the power tracking signal delay is not affected. This region is bounded by an ellipsoid of rotation, the foci of which are basic (BS) and mobile station (MS). The Central section along the major axis of the ellipsoid is an ellipse with the following characteristics (see Fig. 2), which shows the main section of the area of occurrence paratragedy signals, the second and the mobile stations; r1and r2; - focal radii-vectors; 2a is the major axis of the ellipse; 2b - minor axis of the ellipse, thus:

2a = 2l+(r1+r2) = 2l+Ci,

where C is the speed of light,

(r1+ r2- the path of propagation of the reflected beam, then

< / BR>
- the angle between the velocity vector and the direction of the MS - BS.

In Fig. 2 shows an example of interference on the mobile station four rays of broadband signals with the base station: direct beam BS - MS BS - MS, beam reflected from the object A; the beam BS - E - MC, reflected from an object E; beam BS - TO - MS reflected from object B.

It should be noted that when used at the base stations of the system with code division multiplexing (CDMA) sector antennas with directional diagrams 120othe signals reflected from the region shown by hatching in Fig. 2, to the mobile station with the base station and the base station to the mobile station is not available.

When the movement of the mobile station relative to the base station changes the distance between 21 and, consequently, the parameters of the ellipsoid. As you know (Aces T. I. Selection and information processing in Doppler systems. M., "Soviet radio", 1967) [5], depending what about the shift carrier broadband signal and frequency fading. The maximum fading is observed at 0oor 180owhen the antenna of the mobile station is a direct beam from the base station and reflected from the object E. So at a speed of V = 100 mph Doppler shift of the carrier CDMA reaches f0= 180 Hz, and the frequency of the beating between the direct and reflected rays (fading) is doubled and is Fftd=360 Hz. Minimum, zero, fading when two rays is observed at = 90o. These results are valid for the mobile station with a circular radiation pattern of the antenna.

Explain the phenomenon of nonstationarity of the signal due to the failure-occurrence of different combinations of direct and reflected signals.

In Fig. 3 shows the main sections of ellipsoids spheres of existence interference (fading) broadband signals on a moving mobile station for two moments of time t1and t2. It is evident from Fig. 3 shows that when the mobile station changes the distance between the mobile and base stations. In other words, change the parameters of the ellipsoids of the existence of fading, changing their volume, and the rotation of the main axis of the ellipsoid around the focus of a base station. Therefore, at time t2change the set of the, traumah from objects that are common to these two ellipses, change their characteristics. Can change the angle of arrival of the rays of the base station to the new position of the mobile station, to transform the polarization plane of the reflected radio waves and the received signal strength.

Therefore, to reduce the frequency of fading and its suppression should reduce the scope where it is possible to receive the reflected rays. The first step is to eliminate the signals reflected from objects located in the rear hemisphere of the mobile station, and to concentrate the receiving area symmetrically relative to the direction of the received beam.

The invention

The task, which directed the inventive method of transmission / reception of multipath signals (variants) and a device receiving the transmission signal of the mobile station radio system with code division multiplexing (options), is to increase the noise immunity and increase the capacity of a wireless system with code division multiplexing (CDMA).

The method of acceptance of multipath signals in a cellular radio system with code division multiplexing on the first version of the implementation is as follows. Mobile rays of the signal at the interval of uncertainty for the delay. From M the detected rays emit N M rays, the highest energy level, and carry out their demodulation. The new method is that the decision about the received signal is received by the totality of the N demodulated signals rays. In parallel continue to find new rays and, if the newly detected beam more than the minimum of N previously detected rays, perform demodulation of the newly detected beam. In the reverse direction, the signal passed through the channel of the greatest received signal strength.

Thus the proposed method provides a parallel search modes in the interval of uncertainty for the delay and tracking in each of the L space-separated channels of the reception signal. In the search mode, estimate the time delay and direction of arrival of the beam. In the tracking mode are accurate adjustment of the delay and direction of arrival of the beam. The implementation of the method according to this variant provides the reception and processing of the light signal with maximum energy. The signal in the opposite direction transmit with the maximum power of the received signal.

The method of acceptance of multipath signals in a cellular radio system with code division multiplexing WTO is the Riem signal. In each channel are searching rays of the signal at the interval of uncertainty for the delay. From M the detected rays emit N M rays, the highest energy level, and carry out their demodulation. The new method is that the decision about the received signal is received by the totality of the N demodulated signals rays. In parallel demodulation spend averaged estimate of the Doppler shift of the carrier frequency of one or more beams, the direction of the parish whose maximum coincides with the direction of movement of the mobile station. The obtained average score is used to calculate the Doppler shift of the carrier frequency in the rest of spatially separated receiving channels as a projection of the value of this average valuation on the direction of the designated channel, this suggests that the direction of arrival of the rays coincides with the orientation of the spatially dispersed receive channel. The obtained results are used for compensation of Doppler shift of carrier frequency demodulated signals in each spatially separated receive channel. In parallel continue to find new rays taking into account the Doppler frequency shift in each channel. If the newly detected beam is more, che is the direction of the signal passed through the channel of the greatest power of the received signal adjusted by the Doppler shift of each spatial-posted channel.

Thus, the second variant implementation of the method in addition to the search modes in the interval of uncertainty for the delay and tracking in each of the L spatially dispersed channels of acceptance to estimate and compensate for Doppler frequency shifts in the received signals, facilitating thus the possibility of implementing modes of coherent reception.

To implement the method in the first embodiment serves two embodiments of the device of the reception signal of the mobile station.

The device of handover of the mobile station multipath signals in a communication system with code division multiplexing on the first version as a prototype [3], contains the antenna, the diplexer, the analog receiver, the receiver search, L receivers, data, control processor, the power combining signals from the decoder, the block of user data, the modulator of the transmitter, the power control of the transmitter, the power amplifier of the transmitter. The new device is that formed L in a similar and parallel branches of the reception signal, in each of which the antenna is made spatially oriented with a narrow radiation pattern. Wormation signals from receivers of data. The second switching unit is introduced to connect the transmitter output to the channel on which the signal is received the maximum level.

The device of handover of the mobile station multipath signals in a communication system with code division multiplexing on the second version as a prototype [3], contains the antenna, the diplexer, the analog receiver, the receiver search, L receivers, data, control processor, the power combining signals from the decoder, the block of user data, the modulator of the transmitter, the power control of the transmitter, the power amplifier of the transmitter. The new device is that formed L in a similar and parallel branches of the reception signal, in each of which the antenna is made spatially oriented with a narrow radiation pattern. Additionally, in every branch of the reception signal is entered, the control unit pattern. The control block pattern generates a control signal in accordance with which directs the beam sector antenna angle to obtain maximum response for the input signal.

Put three of the switching unit in the block diagram of ustroystvo switching introduced to connect the transmitter output to the channel, of which is the maximum signal level. The third switching unit is entered to generate control signals control block pattern in each branch of the reception signal.

To implement the method according to the second variant of a device of handover of the mobile station multipath signals, which in addition to the previous two options enables evaluation of the Doppler shift of the carrier frequency to compensate for Doppler frequency shifts in the received signals. For this purpose, the authors have developed a unit of measurement of Doppler frequency shift, which may be implemented as a device in the first embodiment, and the device according to the second embodiment.

For example, if the unit of measurement of Doppler frequency shift to include in the block diagram of the device of the reception signal of the mobile station according to the first implementation variant, the device of handover of the mobile station multipath signals according to a third embodiment will contain all the characteristics of the proposed device in the first embodiment, while further comprises an evaluation unit of Doppler frequency shift.

RS radio system with code division multiplexing (prototype). Fig. 2 illustrates the main section of the area of occurrence of the reflected signals that cause fading wideband signals, where 2l is the distance between mobile and base stations; r1 and r2 are the focal radii-vectors; 2a is the major axis of the ellipse; 2b - minor axis of the ellipse. Fig. 2 as the example illustrates the fading in the mobile station (MS) four rays of broadband signals with the base station: direct beam; beam BS AND MS, reflected from an object A; beam BS - E - MC, reflected from an object E; beam BS - TO - MS reflected from object B. Fig. 3 illustrates the major sections of the ellipsoids of the areas of existence of fading wideband signals on a moving mobile station for two times t1 and t2. In Fig. 4 shows the block diagram of the device of the reception signal of the mobile station radio system with code division multiplexing (claimed device in the first embodiment), Fig. 5 is a block diagram of the device of the reception signal of the mobile station radio system with code division multiplexing (claimed device according to the second variant), Fig. 6 is a block diagram of the device of the reception signal of the mobile station radio system with code division multiplexing (the inventive device according to a third the spine of the extreme of the regulatory system, one of the coordinates of this system is the delay () and the other coordinate is the angle of deviation of the axis of the beam from the direction to the signal source in azimuth , the third coordinate of the samples of the correlation function Bi(,) of the received signal.

The possibility of carrying out the invention

The device of handover of the mobile station multipath signals in a communication system with code division multiplexing in the first embodiment is performed as follows (Fig. 4).

For acceptance of multipath signal generated L similar branches of the reception signal. In each branch of the reception-signal reception is carried out on a spatial-oriented antenna with a narrow beam-1-1 - 1-L.

The total pattern of all sector antennas 1-1 to 1-L forms a circular pattern, therefore, provides the opportunity for timely analysis of the incoming signal from various directions receivers search 4-1 to 4-L. thus by the maximum response at the outputs of receivers 4-1 search - 4-L is determined by a corresponding time delayjdirection with accuracy to the number of sector received beam and its capacity is of fading, not exceeding the specified value.

With the output of each of the antennas 1-1 to 1-L signal is applied to diplexer 2-1 to 2-L, which provide full-duplex operation mode of the mobile station.

Output signals from diplexers 2-1 to 2-L are received in corresponding analog receivers 3-1 to 3-L, which converts the analog signal to digital and transmit it to the receiver searches 4-1 - 4-L and the data receivers 5-1 to 5-L, as well as a control signal to the power control of the transmitter 10.

Receivers search 4-1 to 4-L analyze the input signal sequentially delay the entire length of the pseudorandom sequence and in parallel in all sectors of the pattern in the direction of.

For example, if the receiver input of the search in the first sector of a pie chart the direction the signal is present with the current delayjthe pseudo-random sequence generator search, then the output of the receiver search 4-i receive a response in the form of the correlation functioni. the value of which corresponds to a time delay and angle of arrival of the rayj< / BR>
In the process of finding the output of Bj;i), all receivers search 4-1 to 4-L for the entire region of uncertainty vremennyi CPU 6 selects the current N of M L maximum values of correlation functions. Upon completion of the search cycle rays on the propagation delay of N maximum values B(j,i) make the transition to the tracking mode for these N rays. For this control processor 6 selects the N receivers of data from 5-1 to 5-L, setting pseudorandom generators in them in the position corresponding to the maximum of B(j,i).

At the same time the first outputs of the data receivers 5-1 to 5-L, which are information, via the first switching unit 12 is connected to the power combining signals from the decoder 7. The first switching unit 12 is entered in the block diagram of the inventive device for selecting the maximum of information signals from the data receivers 5-1 to 5-L and transfer them to the block combining signals from the decoder 7. That is, the first switching unit 12 connects the N of M L outputs data receivers 5-1 to 5-L, with the greatest response to the block combining signals from the decoder 7, and carries out the replacement of them by the results of parallel analysis of the received signal receivers search 4-1 to 4-L.

Information sequences of different beams are combined by delays and added in a block of combining signals from the decoder 7, thus ensuring maximum the rays and tracking maximum of them are parallel. Upon detection of a more powerful beam provides tracking them and replace them with the least power beam unit combining signals from the decoder 7.

Use pie charts orientation of the satellite-tracking channels for transmission of the information signal allows sparingly and purposefully use the power of the transmitter in the return channel and to get the best performance of the communication system in terms of noise and fading.

The second switching unit 13 connects the transmitted signal with the required power (energy) to the diplexer of the branches of the reception signal in which the received signal is the greatest (maximum).

Control processor 6 in accordance with information received manages data receivers 5-1 and 5-L, receivers search 4-1 - 4-L, the modulator of the transmitter 9 and the power control of the transmitter 10. Together with the receiver search 4 control processor 6 organizes continuous search of the base station signal, forming a pseudo-random sequence with the corresponding time delays. Found a variety of responses highlights N the largest and records the corresponding time position of the pseudo-random sequence N most of the signals and tracks the delays of these signals. Control processor 6 in accordance with the information received from the data receivers 5-1 to 5-L generates a control signal for power control of the transmitter 10 and the required encoding signals for the modulator of the transmitter.

The block combining signals from the decoder 7 summarizes the N signals from the data receivers 5-1 to 5-L with delay and decodes the received total signal. The output signal of this block is fed to the block user data 8.

The block user data 8 converts adopted decoded digital information signal in the form corresponding to the user devices (Fax, display - digital form, microphone - analog) and converts the data message to the user in digital form to the modulator of the transmitter.

The modulator of the transmitter 9 generates a signal for the transmitter of the mobile station (encoding Walsh, I, Q, L - pseudo-random sequence, etc.).

In the power control of the transmitter 10, the signal of the intermediate frequency modulated signal from the modulator of the transmitter 9. The result is a pseudo-random signal at the intermediate frequency, which is governed by the power control signals from analog p is the power amplifier 11, the output signal from the power control of the transmitter 10 is converted into an output RF signal of the transmitter of the mobile station, increase in power to the desired level and is fed through a switching unit 13 to one of diplexers 2-1 - 2.

The proposed device allows reception and transmission of information with the best quality as it provides separate (independent) the reception of signals coming from different directions, which reduces the effect of fading, improves the signal to noise ratio, allows to reduce the transmitting power of the mobile station, and also reduces the level of mutual interference between users.

The device of handover of the mobile station multipath signals in a communication system with code division multiplexing according to the second variant performed as follows (Fig. 5).

For acceptance of multipath signal shape L similar branches of the reception signal. Each of which reception is carried out on a spatial-oriented antenna with a narrow beam-1-1 - 1-L.

The total pattern of all sector antennas 1-1 to 1-L forms a circular pattern, therefore, provides the opportunity for timely analysis of the incoming signal with different directions of priem the corresponding time delayjdirection with accuracy to the number of sector received beam and its power.

Each directional sector antenna is selected from a frequency of fading that does not exceed a specified value. The control block pattern 15-1 to 15-L signal from the switching unit 14 changes the direction of the directional sector antennas within no more than half of the aperture pattern in a specific sector.

With the output of each of the antennas 1-1 to 1-L signal is applied to diplexer 2-1 to 2-L, which provide full-duplex operation mode of the mobile station.

Output signals from diplexers 2-1 to 2-L are received in corresponding analog receivers 3-1 to 3-L, which convert analog signal to digital and transmit it to the receiver searches 4-1 - 4-L and the data receivers 5-1 to 5-L, as well as a control signal to the power control of the transmitter 10.

Receivers search 4-1-4-L analyze the input signal sequentially delay the entire length of the pseudorandom sequence and in parallel in all sectors of the pattern in the direction of.

For example, if the receiver input of the search in the first sector of a pie di is Telenesti search the output of the receiver search 4-i receive a response in the form of the correlation function value which corresponds to a time delayjthe angle of arrival of the ray i.

In the process of finding the output of Bj;i), all receivers search 4-1 to 4-L for the entire region of uncertainty of time delay and angle of arrival remember in the control processor 6.

At each step of the analysis, the control CPU 6 selects the current N of M L maximum values of correlation functions. Upon completion of the search cycle rays on the propagation delay of N maximum values B(,), make the transition to the tracking mode for these N rays. For this control processor 6 selects the N receivers of data from 5-1 to 5-L, setting pseudorandom generators in them in the position corresponding to the maximum of B(,).

At the same time the second outputs of the N receivers data from 5-1 to 5-L through the third switching unit 14 are connected to their respective control blocks pattern 15-1 to 15-L, and the third switching unit 14 is entered in the block diagram of the inventive device as the control for the control unit of the pattern in each branch of the intake-p is for switching 12 is connected to the power combining signals from the decoder 7. The first switching unit 12 is entered in the block diagram of the inventive device for selecting the maximum of information signals from the data receivers 5-1 to 5-L and transfer them to the block combining signals from the decoder 7. That is, the first switching unit 12 connects the N of M L outputs data receivers 5-1 to 5-L containing (have) the greatest response to the block combining signals from the decoder 7, and carries out the replacement (substitution) on the results of the analysis of the received signal receivers search 4-1 to 4-L.

The control block pattern in each branch of acceptance 15-1 to 15-L focuses the beam sector antenna angle to obtain maximum B(,).

Information sequences of different beams are combined by delays and added in a block of combining signals from the decoder 7, thus ensuring maximum signal-to-noise ratio at the output of the combining signals from the decoder 7.

Next, the processes of searching rays and tracking maximum of them are parallel. Upon detection of a more powerful beam provides tracking them and replace them with the least power beam unit combining signals from the decoder 7.

Use pie charts e.g. lesofat power of the transmitter in the return channel and to get the best performance of the communication system in terms of noise and fading. It should be noted that the small tuning range pie chart orientation does not affect the process of finding new rays.

The second switching unit 13 connects the transmitted signal with the required power (energy) to the diplexer of the branches of the reception signal in which the received signal is the greatest (maximum).

Control processor 6 in accordance with information received manages data receivers 5-1 and 5-L, receivers search 4-1 - 4-L, the modulator of the transmitter 9 and the power control of the transmitter 10. Together with the receiver search 4 control processor 6 organizes continuous search of the base station signal, forming a pseudo-random sequence with the corresponding time delays. Found a variety of responses allocates N of M L and greatest captures the corresponding time position of pseudorandom sequences.

Control processor 6 together with the data receivers 5-1 to 5-L provides processing found N of M L most of the signals and tracks the delays of these signals. Control processor 6 in accordance with the information received from the data receivers 5-1 to 5 - L forms the control tx2">

The block combining signals from the decoder 7 summarizes the N of M L signals from the data receivers 5-1 to 5-L with delay and decodes the received total signal. The output signal of this block is fed to the block user data 8.

The block user data 8 converts the decoded digital information signal in the form corresponding to the user devices (Fax, display - digital form, microphone - analog) and converts the data message to the user in digital form to the modulator of the transmitter.

The modulator of the transmitter 9 generates a signal for the transmitter of the mobile station (encoding Walsh, I, Q, L - pseudo-random sequence, etc.). In the power control of the transmitter 10, the signal of the intermediate frequency modulated signal from the modulator of the transmitter 9. The result is a pseudo-random signal at the intermediate frequency, which is governed by the power control signals from analog receivers 3-1 to 3-L and control processor 6 and is directed to the power amplifier of the transmitter 11.

In the power amplifier 11, the output signal from the power control of the transmitter 10 is converted into an output RF signal of the transmitter mobile art is.

In the implementation of the method of acceptance of multipath signals and devices for their implementation (options) the most difficulties can arise with the performance of the sector antenna system with mutually independent directional diagrams. This is because the mobile communication system of the most important criteria are the geometric dimensions of the structure, which is directly connected with the working frequency range. The lower the frequency, the greater the size of the antenna system. With increasing carrier frequency in the system with code division multiplexing reduced geometrical dimensions of the antenna system of sector antennas and easier provided with the required directivity. For example, in the range of 850 MHz, the geometric dimensions of the elementary sector three-element directional antenna type "wave channel" (vibrator, reflector, etc.,) are 200 70 mm Aperture pattern on half power level (level 0,707) from a maximum of a = 65o. The frequency of fading in the sector will not exceed 17 Hz. The circular pattern is formed of the six sectors. This antenna system can be placed on the roof of the car.

Management romanichesky drives torque each sector antenna in the horizontal plane around the point of Centroamericana pattern independently from each other.

Thus there are two possible variants of realization of the device of the transmission / reception of multipath signals with orientation and without the orientation of the directional sector antennas on the maximum received beam.

It should be noted that the advantages of pie reception with controlled orientation have the potential boundary defined by the accuracy of parameter estimation and complexity of the technical implementation. When the number of sectors (narrower beam) management of the pie chart orientation becomes impractical because of excessive suppression of fading determined by the aperture (width) of the pattern, will complicate the implementation of the antenna without a noticeable improvement in noise immunity.

Therefore, the use of the first or second proposed solution will depend on the specific operating conditions of the mobile station.

Evaluation of the effect of reducing the fading can be given on the example of the reception of two rays. Let a ray of light comes on the axis of the sector chart napravlennost the axis of the beam, and the beam coming at an angle where the angle of aperture of the radiation pattern of a sector. The frequency of the beating between the carrier in this simplest case is to determine the maximum fading branches of the reception signal.

When a pie chart orientation and VR= 100 miles/h frequency fading in the input group signal can reach 360 Hz. For pie charts orientation with an angle of aperture = 30oand VR= 100 miles/h frequency fading in the input group the CDMA signal will not exceed 4 Hz. This fading is able to track how the power tracking signal delay and phase locked loop frequency. Therefore, a possible mode of coherent reception signal information and improving the noise immunity of the system.

In addition, a pie chart orientation allows you to reduce the background from other users and background from their own paratragedy rays, a delay which exceedsi. When uniformly dense placement of users in a cell of the background level at the mobile station from other CDMA users will fall times that if = 30n = 12 corresponds to the reduction of background noise from other users about 11 dB.

Another possibility is povysheniya on the same sectors, which are the best reception of the information on the mobile station. In this case, the power emitted by the transmitter of the mobile station can be reduced by approximately n times, where n is the number of sectors. This additionally reduces background noise for neighboring base stations.

In connection with the possibility of temporary breeding treated group signals, without loss of generality, let us now consider the tracking of one of the rays.

In the process of tracking individual beam and the group of beams laid down the same principle of control to the maximum of the correlation function signal. And since this maximum is achieved by changing the delay time pseudo-random sequence and orientation of maximum beam on the signal source, in addition to achieve this goal, a two-dimensional extreme automatic control system, providing the extremum of the function (Fig. 8). Fig. 8 illustrates the body of the extreme uncertainty of the regulatory system. One of the coordinates of this system is the delay () and the other coordinate is the angle of deviation of the axis of the beam from the direction to the signal source in azimuth , the third coordinate - timing correlation f is, for fixed values =0and =0, i.e., B0) and B(,0).

There are two main options provide access to the extremum of the function B(,).

The first is a sequential method Gauss-Seidel (A. A. Krasovskii, G. S. Pospelov. Fundamentals of automation and technical Cybernetics. Moscow, Leningrad. State energy publishing house, 1962, S. 510 [5] when the first is auto-adjustment delay circuit tracking signal delay, and then by the angle of arrival of a signal control system diagram antenna.

The second method is a parallel method of steepest descent gradient method [5] , in which the adjustment is calculated according to two parameters simultaneously to achieve and retain the greatest response by B(,). When this blocks the tracking signal delay and orientation of the partial directional diagrams must be consistent, best - performance, noise, accuracy of the tracking beam.

To implement the method according to the second variant of a device of handover of the mobile station multipath signals, which in addition to the previous two options enables evaluation of the Doppler shift of the carrier frequency and to compensate for desdicha frequency, which can be implemented as a device but the first option and the device according to the second embodiment.

For example, if the unit of measurement of Doppler frequency shift to include in the block diagram of the device of the reception signal of the mobile station according to the first implementation variant, the device of handover of the mobile station multipath signals according to a third embodiment will contain all the characteristics of the proposed device in the first embodiment, while further comprises an evaluation unit Doppler frequency shift (Fig. 6).

The evaluation unit of the Doppler frequency shift 16 (Fig. 7) in the device receiving the transmission signal of the mobile station operates as follows.

In parallel with the reception and the search signal estimate of the Doppler shift of the carrier frequency in the spatial-spaced channel oriented along the direction of motion of the mobile station. The evaluation calculates the Doppler shift of the carrier frequency in each spatial-spaced channel, which is defined as the projection of the values of this average valuation on the direction of the designated channel, this suggests that the direction of coming up with the Doppler in the i-th and k-th channels, iandtothe angular orientation of the i-th and k-th channel relative to the channel, oriented in the direction of movement of the mobile station.

The results obtained are used to compensate for the Doppler shift of the carrier frequency in each spatially separated receiving channel so that the converted carrier frequency after compensation has adopted the following value:

< / BR>
where the converted carrier frequency of the i-th (current) channel

f0- the nominal value of the carrier frequency,

fdithe true value of Doppler shift of carrier frequency i (current) channel

evaluation of the Doppler frequency in the i-th (current) channel.

In the reverse direction, the signal passed through the channel most power at the carrier frequency is adjusted to the Doppler shift in each channel.

The unit of measurement of Doppler frequency shift for the device receiving the transmission signal of the mobile station can be performed, for example, as shown in Fig. 7: receiver 17, a transmitter 18, a reference generator 19, the node measurement period of the difference frequency receiver and transmitter 20 and an analog-to-digital Converter 21.

The invention can be used in Prien ottoway the communication system with code division multiplexing, namely, that the mobile station form L spatially dispersed channels of reception signal in each channel are searching rays of the signal at the interval of uncertainty on the delay of the M detected rays emit N M rays, the highest energy level, and implement them demodulation, characterized in that the decision about the received signal is received by the totality of the N demodulated signals rays, in parallel, continue to find new rays and, if the newly detected beam more than the minimum of N previously detected rays, perform demodulation of the newly detected beam, in the reverse direction, the signal passed through the channel of the greatest received signal strength.

2. The method of acceptance of multipath signals in a cellular radio system with code division of channels, namely, that the mobile station form L spatially dispersed channels of reception signal in each channel are searching rays of the signal at the interval of uncertainty on the delay of the M detected rays emit N M rays, the highest energy level, and implement them demodulation, characterized in that the decision about the received signal is received on set N of shift of the carrier frequency of one or more beams, direction of arrival which most coincides with the direction of movement of the mobile station received the average score is used to calculate the Doppler shift of the carrier frequency in the rest of spatially separated receiving channels as a projection of the value of this average valuation on the direction of the designated channel, this suggests that the direction of arrival of the rays coincides with the orientation of the spatially dispersed receive channel, the obtained results are used for compensation of Doppler shift of carrier frequency demodulated signals in each spatially separated receive channel, in parallel, continue to find new rays taking into account the Doppler frequency shift in each channel, and if the newly detected beam more than the minimum of N previously detected rays, perform demodulation of the newly detected beam in the reverse direction, the signal passed through the channel of the greatest power of the received signal adjusted by the Doppler shift of each spatial-posted channel.

3. The device receiving the transmission signal of the mobile station radio system with code division of channels containing the antenna, the output of which is coedine connected to the first input of the receiver search and the first input L of the data receivers, another output of the analog receiver connected to the first input of the power control of the transmitter, the second receiver input search is connected with a corresponding first output control processor, the output of the search is connected with a corresponding first input of the control processor, the second input of each data receiver is connected to the corresponding second L outputs a control processor, the output of each data receiver is connected to the corresponding input of the combining signals from the decoder, the output of which is connected with a block of user data, the first output of which is a data output and a second output connected to the first input of the modulator of the transmitter, the second input is connected to the third output control processor, and the output of the second controller input transmitter power, a third input which is connected to the fourth output of the control processor, the first controller output power of the transmitter is connected to a second input of the control processor, and a second output from a power amplifier of the transmitter, the output of which is connected with the second input diplexer, the second output of which is connected to the antenna, the output of which is an output informatiile located branches of the reception signal, moreover, in each branch of the reception signal of the antenna is made spatially oriented with a narrow radiation pattern, introduced two of the switching unit, when L information input unit combining signals from the decoder are connected to their corresponding outputs L receivers of data through the first switching unit, and the output of the power amplifier of the transmitter with the second input of the diplexer in each branch of the reception signal through the second switching unit, both the switching unit connected to a host processor, the first of which - to the fifth output and the second to the sixth output, the information output device in the reverse direction is output antenna of the branches of the reception signal in which the level of a received information signal is maximum power.

4. The receiving device of the mobile station radio system with code division of channels containing the antenna, the output of which is connected to the first input of the diplexer, the output of which is connected to the input of an analog receiver, the first output of which is connected to the first input of the receiver search and the first input L of data receivers, the other output of the analog receiver connected to the first input reggada control processor, the output of each receiver search connected with a corresponding first input of the control processor, the second inputs L of the data receivers are connected with the corresponding second outputs of the control processor, the output of each data receiver is connected to the corresponding input of the combining signals from the decoder, the output of which is connected with a block of user data, the first output of which is a data output and a second output connected to the first input of the modulator of the transmitter, the second input is connected to the third output control processor, and the output of the second controller input transmitter power, a third input which is connected to the fourth output of the control processor, the first controller output power of the transmitter is connected to a second input of the control processor, and a second output from a power amplifier of the transmitter, the output of which is connected with the second input of the diplexer, the second output of which is connected to the first antenna input, a second output which is the output data signal of the user in the opposite direction, characterized in that the formed L in a similar and parallel branches of the reception signal, and in napravlennosti, in every branch of the reception signal is entered, the control block pattern, introduced the first, second and third switching units in each branch of the reception signal is entered, the control block pattern, with L the information input unit combining signals connected to the corresponding first output L of the data receivers through the first switching unit, the output of the power amplifier of the transmitter with the second input of the diplexer in each branch of the reception signal through the second switching unit, and the second output of each data receiver is connected to the corresponding input of the control block pattern in their branch of the reception signal through the third switching unit, and three of the switching unit connected to a host processor, the first of which - for the fifth output, the second to the sixth output, and the third to the seventh output control processor, the output control unit pattern connected to the third input of the antenna; and an information output device in the reverse direction is output antenna of the branches of the reception signal in which the level of a received information signal is maximum power.6. The device under item 5, characterized in that the evaluation unit Doppler frequency shift comprises a receiver, a transmitter, a reference generator, site measurement period of the difference frequency transmitter and receiver and analog-to-digital Converter, the first input of the receiver is the input of the evaluation unit of Doppler frequency shift, the second input of the receiver connected to the transmitter output, the first output of the reference generator is connected to the input of the transmitter and the third receiver input, the second output of the reference generator connected to the first input node of the measurement period of the difference frequency receiver and transmitter, a second input connected to the output of the receiver, and the output with the input of the analog-to-digital Converter whose output is the first output of the evaluation unit of Doppler frequency shift, the second output unit of measurement of Doppler frequency shift is the output of the transmitter.

 

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FIELD: communication systems.

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EFFECT: enhanced reliability of mobile communication system.

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FIELD: information technologies.

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22 cl, 7 dwg

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