CN100571054C - Downlink multipath search method and device in wideband code division multiple access communication system - Google Patents

Abstract

The invention discloses a downlink multipath search method in a wideband code division multiple access communication system. The multipath search window to be tested is equally divided into two or more time periods, and one or more than one sampling is set in each time period. point, the method also includes the following steps: a. perform one or more symbol-level cumulative averages on the time axis for each sampling point in each period in turn, and store the calculation results of all sampling points; b. complete all periods After the symbol-level cumulative average operation of each sampling point in the multipath search window, do one or more symbol-level cumulative averages on the time axis for each sampling point in the multipath search window, and store the calculation results of all sampling points. The invention also discloses a downlink multipath search device in the wideband code division multiple access communication system at the same time. The method and device of the invention can effectively reduce hardware resources and be easy to implement.

Description

Downlink multipath search method and device in wideband code division multiple access communication system

technical field

The invention relates to multipath search technology, in particular to a downlink multipath search method and device in a wideband code division multiple access (WCDMA) communication system.

Background technique

The WCDMA communication system is a spread spectrum communication system. The so-called spread spectrum communication means that the signal transmitted in the system is extended to a very wide frequency band, that is, the signal bandwidth of the information transmitted by the spread spectrum communication is much larger than that of the original information itself. bandwidth. In this system, the signal transmitted to the receiver is despread to recover the original transmitted data. Communication based on such a system requires precise synchronization between the receiver and the sender.

Because the wireless communication channel is a multipath fading channel, that is, the signal reaching the receiver after propagating through this channel will produce multipath delay, and each path has different transmission delay and fading. Since the phase of each multipath signal when it arrives at the receiver is random, the added signals are either superimposed and enhanced, or offset and weakened, resulting in a fading valley point on the time axis of the signal power arriving at the receiver. At these time points The upper signal-to-noise ratio is extremely low, which is not conducive to reception. In a WCDMA communication system, an effective and commonly used method to combat multipath fading is to use a RAKE receiver to organically combine independent signals scattered in each path, thereby improving the signal-to-noise signal at the receiving end. Specifically, it is: to detect and measure the multipath, determine and track the searched multipath from time to time, then demodulate the resolvable multipath signals separately, and divide the demodulated signals of each path according to a certain Criteria for coherent merging. In the WCDMA communication system, multipath detection and parameter measurement are completed by the multipath search module.

Since in WCDMA communication systems, the range of multipath offset generally does not exceed 256 chips (chip), so in practical engineering, the correlator group method is usually used, that is, multiple correlators are used in different phases to match the input sequence Correlation operations are performed, and multipath information is determined from the results of all correlators according to certain rules. If a correlator is used for correlation calculation on each phase to be detected, then for a multipath search module whose search accuracy is 1/N chip and the multipath range to be searched is 0~R-1chips, the required parallel correlator The number of resources is N×R, and it is not desirable in practical application that the multipath search module occupies so many hardware resources. Certainly, the method of increasing the operating frequency of the correlator and time-division multiplexing can be adopted to provide the utilization rate of unit hardware resources as much as possible, thereby reducing hardware resources. However, the downlink multipath search module in the WCDMA communication system is set in the baseband processing chip of the mobile station. This design method is used in addition to the increase in the design of the Application Specific Integrated Circuit (ASIC, Application Specific Integrated Circuit) chip. In addition to the difficulty of ASIC back-end design, the increase in operating frequency will also increase the power consumption of the baseband processing chip and reduce the standby time of the mobile station, thus greatly affecting the working performance of the mobile station.

In summary, the existing problems in the prior art are: if the operating frequency of the correlator is not increased, too many parallel correlator hardware resources will be occupied; if the operating frequency of the correlator is increased, the difficulty of ASIC back-end design will be increased, and Increase the power consumption of the baseband processing chip of the mobile station.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a downlink multipath search method in a wideband code division multiple access communication system, which can effectively reduce hardware resources and is easy to implement.

Another object of the present invention is to provide a downlink multipath search device in a wideband code division multiple access communication system, which can effectively reduce hardware resources.

In order to achieve the above object, technical solution of the present invention is achieved in that way:

The invention provides a downlink multipath search method in a wideband code division multiple access communication system, which divides the multipath search window to be tested into two or more time periods, and sets one or more sampling times in each time period point, the method also includes the steps of:

a. Do one or more symbol-level cumulative averages on the time axis for each sampling point in each period in turn, and store the calculation results of all sampling points;

b. After completing the symbol-level cumulative average operation of each sampling point in all time periods, do one or more symbol-level cumulative averages on the time axis for each sampling point in the multipath search window, and store the calculation of all sampling points result.

Wherein, the number of sampling points set in each period is the number of parallel correlators in the downlink multipath search device in the wideband code division multiple access communication system.

Wherein, the number of periods into which the multipath search window is equally divided is: the product of the number of chips in the multipath search window and N1 and the number N2 of the parallel correlators, where N1 is greater than or equal to 2.

Among them, the number of times that each sampling point in each time period described in step a performs symbol-level cumulative averaging on the time axis and the number of times that each sampling point in the multipath search window described in step b performs symbol-level cumulative averaging on the time axis Satisfied: the product of the two is equal to the number of symbol-level cumulative averages of each sampling point on the time axis in the entire multipath search window.

Wherein, step a further includes: each parallel correlator and the expansion code generation module in the downlink multipath search device in the wideband code division multiple access communication system suspend work between every two adjacent time periods , the pause time is the number of sampling clock cycles of the parallel correlator.

Wherein, in step b, in the process of performing one or more symbol-level cumulative averaging on the time axis for each sampling point in the multipath search window, between performing symbol-level cumulative averaging each time, each parallel correlation The device suspends work, and the expansion code generation module accelerates 256 sampling clock cycles at the same time; the number of sampling clock cycles of the pause time is obtained by the following formula:

256×N1-(M2-1)×N2, where M2 is the number of time periods divided into equal parts by the multipath search window.

The present invention also provides a downlink multipath search device in a wideband code division multiple access communication system, comprising: a correlator control signal generation module, a parallel correlator group module, an addition and extension code generation module, and a correlation result storage module;

The correlator control signal generating module is used to control the parallel correlator group module and the adding and spreading code generating module, its first output terminal is connected to the parallel correlator group module, and its second output terminal is connected to the parallel correlator group module. The extension code generating module is connected;

The parallel correlator group module is used to perform symbol-level cumulative averaging on the input signal, and its first input terminal receives the data sampled by N1 times the chip rate clock, and the second input terminal is connected to the said adding and spreading code generation module , the output terminal is connected to the correlation result storage module;

The adding and spreading code generation module is used to generate the adding and spreading code and output it to the parallel correlator group module;

The correlation result storage module is used to store the output result of the parallel correlator group module.

Wherein, the correlator control signal generation module includes: a first counter, a second counter, a third counter and a control signal generation unit;

The first counter is used to count the number of symbol-level cumulative averages of each sampling point on the time axis in the period divided into equal parts by the multipath search window, and its output terminal is connected to the control signal generation unit;

The second counter is used to count the number of periods divided into equal parts by the multipath search window, and its output terminal is connected to the control signal generation unit;

The third counter is used to count the number of symbol-level cumulative averages of each sampling point in the multipath search window on the time axis, and its output terminal is connected to the control signal generation unit;

The control signal generating unit is configured to output a control signal to the parallel correlator group module and the adding and spreading code generating module according to the count values of the first, second and third counters, and its first output terminal is connected to The parallel correlator group modules are connected, and the second output terminal is connected to the adding and spreading code generating module.

Wherein, the parallel correlator group module includes one or more parallel correlators, the first input terminal of each parallel correlator receives the data sampled by N1 times the chip rate clock, and the second input terminal is connected to the expanded The code generation module is connected, and the output terminal is connected with the correlation result storage module.

Wherein, the adding and spreading code generation module includes an adding and spreading code generating unit and a delay unit corresponding to the number of parallel correlators; the adding and spreading code generating unit includes a channel code generator and a scrambling code generator, Exclusive OR operation is performed on the scalar output from the channel code generator and the complex vector output from the scrambling code generator, and the operation result is output to the corresponding parallel correlator through the delay unit.

Wherein, the correlation result storage module includes memories with the same number of periods as the multipath search window; each memory includes a storage unit with the same number of parallel correlators, and the storage unit is used to store its corresponding parallel correlators. The result of symbol-level cumulative averaging of correlator operations.

Wherein, all the storage units are equally divided into a first random access memory and a second random access memory, and the first random access memory is used to store the result of the symbol-level cumulative average operation performed by the parallel correlator whose serial number is an odd number, and the second random access memory It is used to store the operation result of symbol-level accumulation and averaging performed by the parallel correlators whose sequence number is even.

Wherein, the random access memory is a single-port random access memory.

According to the technical scheme of the present invention, since the multipath search window to be measured is divided into two or more periods, and each period is provided with the same number of sampling points as the number of parallel correlators, the maximum number of parallel correlators is reduced. hardware resources. In addition, because the number of delay units corresponding to the number of parallel correlators is used to replace the number of addition and extension code generation units corresponding to the number of parallel correlators in the generation module of the addition and extension codes, the effect of reducing hardware resources is also obtained.

Furthermore, since all the storage units are equally divided into two single-port random access memories (RAMs), and the first single-port RAM is used to store the result of the symbol-level cumulative average operation performed by the parallel correlator whose serial number is odd, the second single-port RAM is used for Stores the symbol-level accumulation and average calculation results of parallel correlators with even serial numbers, effectively avoiding the problem that single-port RAM must work on both edges of the clock signal, thus greatly reducing the difficulty of ASIC back-end design.

Description of drawings

Fig. 1 is the composition structure schematic diagram of downlink multipath search device in wideband code division multiple access communication system of the present invention;

Fig. 2 is a schematic diagram of the realization principle of the operation of the parallel correlator group module and the adding and spreading code generating module in Fig. 1;

Fig. 3 is a schematic diagram of the relationship between the parallel correlator and the sampling time of the adding and spreading code generation unit on the time axis;

Fig. 4 is the flow chart of downlink multipath search method in wideband code division multiple access communication system of the present invention;

Fig. 5 is a schematic diagram of the relationship between a multipath search window, a period and a sampling point;

6 is a schematic diagram of the implementation of the downlink multipath search method on the time axis in the wideband code division multiple access communication system of the present invention;

7 is a timing diagram of control signals output by the correlator control signal generation module in the downlink multipath search method in the wideband code division multiple access communication system of the present invention.

Detailed ways

The technical features and functions of the present invention will be further described below in conjunction with the accompanying drawings.

Referring to Fig. 1, the downlink multipath search device in the wideband code division multiple access communication system of the present invention includes a correlator control signal generation module 101, a parallel correlator group module 102, an addition and extension code generation module 103 and a correlation result storage module 104 . Wherein, the correlator control signal generating module 101 is used to control the parallel correlator group module 102 and the adding and spreading code generating module 103, and its first output terminal is connected to the parallel correlator group module 102, the second The two output terminals are connected to the said adding and spreading code generation module 103; the said parallel correlator group module 102 is used to carry out symbol (symbol) level cumulative average to the input signal, and its first input terminal receives through N1 times chip rate clock For the sampled data, the second input terminal is connected with the described addition and extension code generation module 103, and the output end is connected with the described correlation result storage module 104; the addition and extension code generation module 103 is used to generate the addition and extension code and output to The parallel correlator group module 102 ; the correlation result storage module 104 is configured to store the output result of the parallel correlator group module 102 .

The correlator control signal generation module includes: a first counter 201, a second counter 202, a third counter 203 and a control signal generation unit 204;

The first counter is a symbol_No counter 201, which is used to count the number of symbol-level cumulative averages of each sampling point on the time axis in the period (phase) divided into multipath search windows (set), and its output terminal Connected to the control signal generating unit 204;

The second counter is a phase_No counter 202, which is used to count the number of phases that the multipath search window is equally divided into, and its output terminal is connected to the control signal generating unit 204;

The third counter is a set_No counter 203, which is used to count the number of symbol-level cumulative averages on the time axis for each sampling point in the multipath search window, and its output terminal is connected to the control signal generation unit 204;

The control signal generating unit 204 is configured to output a control signal to the parallel correlator group module 102 and the adding and spreading code generating module 103 according to the count values of the symbol_No counter 201, phase_No counter 202 and set_No counter 203, which The first output terminal is connected to the parallel correlator group module 102 , and the second output terminal is connected to the adding and spreading code generating module 103 . Wherein, the symbol_No counter 201 , the phase_No counter 202 and the set_No counter 203 may be down counters or up counters.

Referring to Fig. 1, described parallel correlator group module 102 comprises N2 parallel correlators 601, the first input end of each parallel correlator 601 receives the data I/Q after N1 times chip rate clock sampling, the second input The terminal is connected to the adding and spreading code generation module 103, and the output terminal is connected to the correlation result storage module 104.

The adding and spreading code generating module includes an adding and spreading code generating unit 103 and a delay unit 403 corresponding to the number of parallel correlators 601 . As shown in FIG. 2, the adding and spreading code generating unit 301 includes a channel code generator 402 and a scrambling code generator 401, which is used to combine the scalar output of the channel code generator 402 with the scrambling code generator Exclusive OR operations are performed on the complex vectors output by 401 , and the operation results are output to the corresponding parallel correlators 601 through each of the delay units 403 .

The reason why the delay unit 403 will be set in the adding and spreading code generation module 103 is:

From the downlink of the WCDMA communication system, the data I/Q sampled by N1 times the chip rate clock is serially input into the multipath search module set in the baseband processing chip of the mobile station, that is, one sampling clock cycle is input into one I/Q Q data, that is, the I/Q input to the parallel correlator group module 102 is a serial data stream, so the start time of the work of the N2 parallel correlators 601 does not start from the same time, that is, the 0th sampling time starts The #0 parallel correlator 601 starts the #1 parallel correlator 601 at the first sampling moment, and so on, starts the #N2 correlator at the N2th sampling moment. Referring to Fig. 3, time #0 corresponds to the 0th sampling time, and time #1 corresponds to the first sampling time; the start time of #0 parallel correlator 601 is consistent with the start time of #0 plus spreading code generation unit 301, corresponding to #0 The sampling moment of time; the start moment of #1 parallel correlator 601 is consistent with the start moment of #1 plus and spread code generation unit 301, corresponds to the sampling moment of #1 moment, and so on, until the last sampling in the multipath search window range point.

From the above calculation, it can be easily drawn that N2 addition and spreading code generation units 301 are required to correspond to N2 parallel correlators 601. In order to reduce hardware resources, in the downlink multipath search device of the wideband code division multiple access communication system of the present invention A delay unit 403 is introduced, that is, N2 delay units 403 are used to replace the N2 addition and extension code generating units 301 to realize the addition and extension code input required by the N2 parallel correlators 601 .

The correlation result storage module 104 includes the same memory 501 as the number of phases that the multipath search window is equally divided into; each memory 501 includes the same storage unit 502 as the number N2 of the parallel correlator 601, and each storage unit 502 It is used to store the result of the symbol-level cumulative averaging performed by the corresponding parallel correlator 601 .

In hardware implementation, a single-port RAM is usually used as the correlation result storage module 104, and its depth is the number of all sampling points in the multipath search window. In the case of not increasing the operating frequency of the RAM, you can consider using a single-port RAM, but this requires that the single-port RAM must work on both edges of the clock signal, that is, both the rising edge and the falling edge work, that is, from the RAM on one edge Read data and write data to RAM at the next edge, which will greatly increase the difficulty of ASIC back-end design, so in the device of the present invention, all storage units are equally divided into two single-port RAMs, and RAM 1 is used to store odd numbers RAM 2 is used to store the result of the symbol-level cumulative average operation performed by the parallel correlator 601 with an even number.

Based on the devices shown in FIG. 1 and FIG. 2 , see FIG. 4 and FIG. 6 for the downlink multipath search method in the WCDMA communication system of the present invention.

The physical channel for the multipath search module to perform multipath search is a Common Pilot Channel (CPICH, Common Pilot Channel) with a transmission rate of 30 bits/s and a spreading factor of 256.

Referring to Fig. 4, this method comprises the steps:

In step 401, the multipath search window to be tested is equally divided into two or more phases, and one or more sampling points are set for each phase.

The number of sampling points set by each phase is the number N2 of parallel correlators 601 in the downlink multipath search device in the wideband code division multiple access communication system, and the number of phases that the multipath search window is equally divided into M2 is obtained by formula (1):

M2＝(R×N1)/N2 (1)

Wherein, R is the number of chips of the multipath search window to be tested, N2 is the number of parallel correlators 601, and N1 is greater than or equal to 2 according to the Nyquist theorem.

In step 402, one or more symbol-level cumulative averages are performed on the time axis for each sampling point in each phase in turn, and the calculation results of all sampling points are stored.

Step 403, after completing the symbol-level cumulative average operation of each sampling point in all phases, do one or more symbol-level cumulative averages on the time axis for each sampling point in the multipath search window, and store the sum of all sampling points Calculation results.

The number of times M1 that each sampling point in each phase in step 402 performs symbol-level cumulative average on the time axis, and the number of times that each sampling point in the multipath search window in step 403 performs symbol-level cumulative average on the time axis The product of M3 is equal to the number S of symbol-level cumulative averages of each sampling point on the time axis in the entire multipath search window.

In step 402, each of the parallel correlators 601 and the adding and spreading code generating module 103 is suspended between every two adjacent phases, and the suspension time is N2 sampling clock cycles.

In step 403, each parallel correlator 601 suspends work between each symbol-level cumulative average, and the number of suspended sampling clock cycles is obtained by formula (2):

256×N1-(M2-1)×N2 (2)

At the same time, the addition and extension code generation module is accelerated to run for 256 sampling clock cycles.

The concrete working principle of device and method of the present invention is like this:

First, the preset values of the symbol_No counter 201 , the phase_No counter 202 and the set_No counter 203 in the correlator control signal generating module 101 are determined according to the size of the multipath search window to be measured.

Take the symbol_No counter 201 , the phase_No counter 202 and the set_No counter 203 as a down counter as an example. Since the parallel correlator group module 102 is a hardware resource, the number N2 of parallel correlators 601 in the module has been determined. As shown in Figure 6, each sampling point in the multipath search window needs to perform symbol-level cumulative averaging on the time axis, that is, the number of times symbol-level cumulative averaging needs to be performed during the entire multipath search process, and it is also to determine the preset values of the three decrement counters one of the factors to be considered.

Assuming that the size of the multipath search window to be measured is R chips, the sampling rate of the I/Q data input by the parallel correlator 601 is N1 times the chip rate, and there are N2 parallel correlator 601 hardware resources in the parallel correlator group module 102, Each sampling point in the entire multipath search window is accumulated and averaged at symbol level for S times on the time axis, and the preset values of symbol_No counter 201 , phase_No counter 202 and set_No counter 203 are respectively set to M1 , M2 and M3 . Referring to Fig. 5, the device of the present invention divides a complete multipath search window into M2 phases, each phase contains N2 sampling points, and the symbol-level accumulation and averaging of these sampling points needs to be done in parallel, so within one phase it corresponds to N2 parallel correlators 601, thus obtaining formula (3):

R×N1＝M2×N2 (3)

The left side of the equation indicates that the number of sampling points in the multipath search window is equal to the product of the size of the multipath search window R chips and N1 times the chip rate; the right side of the equation indicates that the number of sampling points in the multipath search window is equal to a complete The multipath search window is equally divided into M2 phases and the product of the number N2 of corresponding parallel correlators 601 in one phase. Transform formula (3) to get formula (1):

M2＝(R×N1)/N2 (1)

It can be seen from formula (1) that the preset value M2 of the phase_No counter 202 is equal to the quotient of the multipath search window size R chips multiplied by N1 times the chip rate and the number N2 of parallel correlators 601 .

As shown in Figure 6, each sampling point in the multipath search window needs to perform symbol-level cumulative averaging on the time axis, which includes symbol-level cumulative averaging in two senses: one is that each sampling point in the phase is calculated on the time axis The symbol-level cumulative average of one, and the other is the symbol-level cumulative average of all sampling points in the entire search window on the time axis between sets. Since it is assumed that each sampling point in the multipath search window to be tested performs S symbol-level cumulative averages on the time axis, the formula (4) is thus obtained:

(R×N1)×S＝(N2×M1)×M2×M3 (4)

Transform formula (4) to get formula (5):

M1×M3＝((R×N1)×S)/(N2×M2) (5)

Since R×N1=M2×N2, formula (6) can be deduced:

M1×M3=S (6)

That is, the product of the preset value M1 of the symbol_No counter 201 and the preset value M3 of the set_No counter 203 is equal to the times S of symbol-level cumulative averaging of each sampling point on the time axis in the entire multipath search window. For example, each sampling point in the entire multipath search window needs to be accumulated and averaged five times on the time axis, then the preset values of the symbol_No counter 201 and the set_No counter 203 can be M1=1 and M3=5, or M1=5 and M3=1, the former means that each sampling point in each phase performs 1 symbol-level cumulative average on the time axis, and each sampling point in the set performs 5 symbol-level cumulative averages on the time axis; The latter means that each sampling point in each phase performs 5 symbol-level cumulative averages on the time axis, and each sampling point in the set performs 1 symbol-level cumulative average on the time axis.

Then, according to the preset value calculated above, configure the decrement counter in the correlator control signal generation module 101: the preset values M1, M2 and M3 of the symbol_No counter 201, phase_No counter 202 and set_No counter 203, the correlator control signal generation module 101 outputs corresponding control signals according to the processing procedure of the present invention, and controls the parallel correlator group module 102 and the adding and spreading code generating module 103, specifically as follows:

Referring to Fig. 6, firstly, the parallel operation of N2 parallel correlators 601 of #0phase is performed. The parallel operation here is slightly different from the commonly referred to as parallel operation, that is, the start time of the correlators is different, that is to say, the start point of the latter correlator It is one sampling clock cycle behind the start point of the previous correlator; the number of symbol-level cumulative averaging at each sampling point in a phase can be obtained by configuring the preset value M1 of the symbol_No counter 201 in the correlator control signal generation module 101 . After each sampling point in a phase has completed M1 times of symbol-level accumulation and averaging on the time axis, N2 calculation results are stored in the corresponding storage unit 502 in the correlation result storage module 104; The number of phases of the correlation operation can be obtained by configuring the preset value M2 of the phase_No counter 202 in the correlator control signal generation module 101. Specifically, after each sampling point in #0phase has completed the symbol-level cumulative average, it starts to do The symbol-level cumulative average of the sampling points in #1phase, and so on, a total of M2 multiplied by N2 sampling points, which just corresponds to a complete multipath search window; complete the symbol level of all sampling points in a multipath search window After the cumulative average operation, M3 symbol-level cumulative average operations can also be performed on each sampling point in the multipath search window on the time axis, where M3 is the preset value of the set_No counter 203 in the correlator control signal generation module 101 .

See Figure 6, the symbol-level cumulative average operation of the 0th to N2-1 sampling points in the multipath search window is done in #0phase, and the correlation cumulative average of the N2 to 2×N2-1 sampling points in the multipath search window The operation is performed in #1 phase. For a parallel correlator 601, after completing the symbol-level accumulation and averaging in the previous phase, it needs to pause for N2 sampling clock cycles before it can correspond to the 0th sampling point in the next phase. For a parallel correlator 601, after completing a symbol-level cumulative average of a set, it needs to pause for 256×N1-(M2-1)×N2 sampling clock cycles before it can correspond to the next symbol-level cumulative average between sets The 0th sampling point of #0phase.

The main scrambling code used in the downlink in the WCDMA communication system is 38400 chips repeated once. After a phase is completed, the phase of the scrambling code generator 401 corresponds to the sampling point of the current phase, and the sampling point of the next phase is the same as The scrambling code of the sampling point of the current phase is synchronized in phase, so the scrambling code generator 401 in the addition and spreading code generation module 103 does not need to be accelerated; when a set of symbol-level accumulation and averaging is completed, the scrambling code occurs The phase of device 401 corresponds to the last sampling point of the multipath search window to be measured, and the 0th sampling point of #0phase of the next symbol level cumulative average between sets corresponds to the 0th sampling point of the multipath search window to be measured. The phase difference between the two scrambling codes is 256 chips, so the scrambling code generator 401 in the adding and spreading code generating module 103 needs to be accelerated to run for 256 sampling clock cycles.

In summary, between phase and phase, each parallel correlator 601 needs to suspend N2 sampling clock cycles, and during this time, the adding and spreading code generating module 103 also suspends work; between set and set , each parallel correlator 601 needs to suspend work for 256×N1-(M2-1)×N2 sampling clock cycles, during this time, the adding and spreading code generation module 103 needs to accelerate to run 256 sampling clock cycles; the above-mentioned control The signals are all generated by the correlator control signal generation module 101, and Fig. 7 is a timing diagram of the control signals for the parallel correlator 601 and the extension code generation module 103 generated by the correlator control signal generation module 101, and the signal in Fig. 7 is a high voltage flat and effective.

The core of the correlator control signal generation module 101 is three down-counters: symbol_No counter 201 , phase_No counter 202 and set_No counter 203 . The control signal generation unit 204 in the module can determine whether the symbol-level cumulative averaging of each sampling point in a phase on the time axis is over according to the current value of the symbol_No counter 201, because when the symbol_No counter 201 is decremented to 0, it means that the counter will be The next phase reloads the preset value, so this flag can be used to determine the output of the indication signal between phases. The control signal generation unit 204 in the module can determine whether the symbol-level cumulative averaging of all sampling points in a set on the time axis is over according to the current value of the phase_No counter 202, because when the phase_No decreases to 0, it means that the counter will be the next The set reloads the preset value, so this flag can be used to determine the output of the indicator signal between sets.

Referring to FIG. 7, all control signals are output based on the inter-phase indication signal and the inter-set indication signal. For example, when the inter-phase indication signal is valid, the parallel correlator 601 and the addition and extension code generation module 103 are suspended for N2 samples. Clock cycle; when the indication signal between sets is valid, the parallel correlator 601 suspends work, because the time for the parallel correlator 601 to suspend work is 256 × N1-(M2-1) × N2 sampling clock cycles, at the same time, the expansion The code generation module 103 accelerates to run for 256 sampling clock cycles, that is, the time for the parallel correlator 601 to suspend work is longer than the time for the acceleration of the addition and extension code generation module 103, so the addition and extension code generation module 103 should be accelerated first, and then paused.

After that, the symbol-level cumulative average operation is performed, as follows:

This step requires the participation of the parallel correlator group module 102 and the adding and spreading code generating module 103 . Referring to Fig. 2, each parallel correlator has two sets of inputs: one set is the data I/Q sampled by N1 times the chip rate clock, and the other set is the complex vector and channel code generated by the scrambling code generator 401 The scalar generated by the device 402 is subjected to an XOR operation to output a complex vector.

Finally, the operation result is stored.

This step requires the participation of the correlation result storage module 104, the purpose of which is to store the symbol-level cumulative average calculation results corresponding to all sampling points within the multipath search window.

In one embodiment of the device of the present invention, the random access memory is a single-port random access memory.

The above specific implementation has described the present invention with a preferred embodiment, but this is only a vivid example for easy understanding, and should not be regarded as limiting the scope of the present invention. Likewise, various possible equivalent changes or substitutions can be made according to the technical solution of the present invention and the description of its preferred embodiments, and all these changes or substitutions should belong to the protection scope of the claims of the present invention.

Claims (13)

1, downlink multi-path searching method in a kind of Wideband Code Division Multiple Access (WCDMA) communication system, it is characterized in that, Multipath searching window to be measured is divided into two or more periods, and each period is provided with one or more sampled point, and this method also comprises the steps:

A. successively each sampled point in each period is being done on the time shaft once or symbol level cumulative mean once, and the result of calculation of storing all sampled points;

B. after finishing the symbol level cumulative mean computing of each sampled point in all periods, each sampled point in the Multipath searching window is being done on the time shaft once or symbol level cumulative mean once, and the result of calculation of storing all sampled points.

2, method according to claim 1 is characterized in that, the number of the sampled point that described each is provided with period is the number of parallel correlator in the downlink multi-path searcher in the Wideband Code Division Multiple Access (WCDMA) communication system.

3, method according to claim 2 is characterized in that, the period number that described Multipath searching window is divided into is: the merchant of the number N2 of the chip number of described Multipath searching window and the product of N1 and described parallel correlator, wherein N1 is more than or equal to 2.

4, method according to claim 3, it is characterized in that, step a in described each period each sampled point on time shaft, do each sampled point in the number of times of symbol level cumulative mean and the described Multipath searching window of step b and on time shaft, do the number of times of symbol level cumulative mean and satisfy: the product of the two equals each sampled point in the whole Multipath searching window is done the symbol level cumulative mean on time shaft number of times.

5, according to claim 3 or 4 described methods, it is characterized in that, further comprise among the step a: add all break-ofves between per two adjacent periods of extended code generation module in each parallel correlator and the described Wideband Code Division Multiple Access (WCDMA) communication system in the downlink multi-path searcher, time out is parallel correlator several sampling clock cycles.

6, method according to claim 5, it is characterized in that, step b described to each sampled point in the Multipath searching window on time shaft, do once or symbol level cumulative mean process once in, doing between the symbol level cumulative mean at every turn, described each parallel correlator break-off adds the extended code generation module simultaneously and quickens 256 sampling clock cycles of operation; The number in the sampling clock cycle of described time out obtains by following formula:

256×N1-(M2-1)×N2

Wherein, the period number that is divided into for the Multipath searching window of M2.

7, downlink multi-path searcher in a kind of Wideband Code Division Multiple Access (WCDMA) communication system is characterized in that, this device comprises correlator control signal generation module, parallel correlator pack module, adds extended code generation module and correlated results memory module;

Described correlator control signal generation module is used to control described parallel correlator pack module and the described extended code generation module that adds, and its first output links to each other with described parallel correlator pack module, and second output links to each other with the described extended code generation module that adds;

Described parallel correlator pack module, be used for input signal is carried out the symbol level cumulative mean, its first input end receives through the data behind the N1 times of spreading rate clock sampling, and second input links to each other with the described extended code generation module that adds, and output links to each other with described correlated results memory module;

The described extended code generation module that adds is used for generation and adds extended code and export to described parallel correlator pack module;

Described correlated results memory module, the output result who is used to store described parallel correlator pack module.

8, device according to claim 7 is characterized in that, described correlator control signal generation module comprises: first counter, second counter, the 3rd counter and control signal generation unit;

Described first counter, each sampled point of period that is used for that the Multipath searching window is divided into is done the number of times of symbol level cumulative mean and is counted on time shaft, and its output links to each other with described control signal generation unit;

Described second counter, the period number that is used for the Multipath searching window is divided into is counted, and its output links to each other with described control signal generation unit;

Described the 3rd counter, the number of times that is used for each sampled point in the Multipath searching window is done the symbol level cumulative mean on time shaft is counted, and its output links to each other with described control signal generation unit;

Described control signal generation unit, be used for count value according to described first, second and the 3rd counter to described parallel correlator pack module and the described extended code generation module output control signal that adds, its first output links to each other with described parallel correlator pack module, and second output links to each other with the described extended code generation module that adds.

9, according to claim 7 or 8 described devices, it is characterized in that, described parallel correlator pack module comprises one or more parallel correlators, the first input end of each parallel correlator receives through the data behind the N1 times of spreading rate clock sampling, second input links to each other with the described extended code generation module that adds, and output links to each other with described correlated results memory module.

10, device according to claim 9 is characterized in that, the described extended code generation module that adds comprises and adds extended code generation unit and the delay unit corresponding with the number of parallel correlator; The described extended code generation unit that adds, comprise channel code maker and scrambled code maker, be used for the scalar of described channel code maker output and the complex vector of described scrambled code maker output are carried out XOR respectively, and operation result is exported to corresponding parallel correlator by described delay unit.

11, device according to claim 10 is characterized in that, described correlated results memory module comprises the identical memory of period number that is divided into the Multipath searching window; Each memory comprises the memory cell identical with the parallel correlator number, and described memory cell is used to store the result of the symbol level cumulative mean of its corresponding parallel correlator computing.

12, device according to claim 11, it is characterized in that, all memory cell are divided into first random asccess memory and second random asccess memory, described first random asccess memory is used to store the operation result that sequence number is the parallel correlator of the odd number symbol level cumulative mean of carrying out, and described second random asccess memory is used to store the operation result that sequence number is the parallel correlator of the even number symbol level cumulative mean of carrying out.

13, device according to claim 12 is characterized in that, described random asccess memory is the single port random asccess memory.

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