JP2012070131A - Communication device, reception signal processing method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress increase in the number of path timings included in a path search result even when a communication device has a plurality of receiving antennas, and to prevent reduction in an S/N ratio of a demodulation result after RAKE combining.SOLUTION: A communication device 1 has a path search part 131. The path search part 131 performs a path search based on a plurality of reception signals to generate a path search result common to the plurality of reception signals, calculates each reception signal quality for the reception signals at a path timing indicated by the path search result, and outputs a mask control signal for instructing so as not to use the path timing and the reception signal with the calculated reception signal quality equal to or less than a predetermined reception signal quality for RAKE combining.

Description

  The present invention relates to a communication apparatus that performs communication by CDMA, a received signal processing method of the communication apparatus, and a program.

In a wireless communication system that performs communication using the CDMA method, a communication device on the receiving side first performs a path search to obtain several path timings that can be correlated with a result of despreading a received signal using a predetermined spreading code. select. Then, the received signal is despread using a spreading code for each selected path timing.
For example, in Patent Document 1, when a communication apparatus performs a path search, the number of effective path timings (the number of multipaths) is reduced when the reception state is good, and the effective number of path timings is increased when the reception state is bad. A method is disclosed. According to this path search method, when the reception state is good, the number of operating fingers can be reduced, so that power consumption can be suppressed.

  Here, in the case of a communication apparatus having a plurality of receiving antennas, if a path search is performed for each received signal (for each receiving antenna) and a path timing is selected for each received signal, the path timing selected as a result of the path search is The number increases in proportion to the number of receive antennas. As the number of selected path timings increases, the data amount of the path search result increases. A CDMA communication apparatus generally sorts and manages path timings included in a path search result in order of timing, and performs path tracking control including path addition and path deletion each time a path search is performed. At this time, if the number of path timings selected in the path search increases, the path tracking control becomes complicated.

Therefore, in order to simplify the path tracking control, there is a method of generating and managing a path search result common to a plurality of received signals instead of managing a path search result for each received signal.
FIG. 7 is a diagram illustrating an example in which the communication apparatus generates a path search result common to a plurality of received signals. In the figure, an example in which a communication apparatus having two receiving antennas selects two path timings is shown.

  FIG. 6A shows the degree of correlation of the result of despreading using the spreading code of the received signal received by one receiving antenna for each path timing (every time). FIG. 6B shows the degree of correlation of the result of despreading using the spreading code of the received signal received by the other receiving antenna for each path timing. In this case, the communication apparatus adds the correlations of the reception signals in both reception antennas for each path timing, and selects two path timings in order from the path timing having the largest total value.

  Specifically, the correlation degree r1111 in FIG. 11A and the correlation degree r1121 in FIG. 10B are the correlation degrees at the same path timing, and the total value obtained by adding them is the same figure ( It is indicated by r1131 of c). Similarly, the correlation degree r1112 and the correlation degree r1122 are correlation degrees at the same path timing, and a total value obtained by adding them is indicated by r1132, and the correlation degree r1113 and the correlation degree r1123 Is the correlation degree at the same path timing, and the total value obtained by adding these is indicated by r1133, and the correlation degree r1114 and the correlation degree r1124 are the correlation degrees at the same path timing. The sum of these values is indicated by r1134.

  Here, the receiving apparatus passes the path timing of the total value r1132 and the path timing of the total value r1133 in descending order of the total value of the correlation degree exceeding the predetermined threshold level represented by the one-dot chain line in FIG. The two path timings are selected. Then, the receiving device performs despreading for each of the received signals obtained by the two receiving antennas at each of the two selected path timings, and obtains four despreading results. Further, the receiving apparatus performs rake combining using these four despread results, and demodulates communication data using the rake combining results.

  In this way, a receiving device having a plurality of receiving antennas selects a path timing common to each antenna in the path search to obtain a path search result, so that the path search can be performed regardless of the number of antennas the receiving device has. The number of path timings included in the result can be made constant, and path tracking control can be simplified.

JP 2004-260355 A

However, using a path timing common to a plurality of receiving antennas as a result of path search may degrade the S / N ratio of the demodulation result after rake combining.
This point will be described with reference to FIG. 7. In the path timing of the total value r1132, the correlation degree r1112 and the correlation degree r1122 both indicate a large (high) correlation degree. As described above, the S / N ratio of the demodulated result after the rake combination is increased by performing the inverse correlation of the received signal at the path timing indicating a large degree of correlation and performing the rake combination using the inverse correlation result.

  On the other hand, in the path timing of the total value r1133, the correlation degree r1113 shows a large correlation degree, but the correlation degree r1123 shows a small (low) correlation degree. The small degree of correlation indicates that the S / N ratio of the received signal at the path timing is low in relation to the signal to be demodulated by the receiving apparatus. Therefore, if rake combining is performed using the inverse correlation result of the received signal at the path timing, the S / N ratio of the demodulation result after rake combining is lowered.

  The present invention has been made in view of such circumstances, and an object of the present invention is to suppress an increase in the number of path timings included in a path search result even when there are a plurality of receiving antennas, and An object of the present invention is to provide a communication device, a received signal processing method, and a program that can prevent a decrease in the S / N ratio of demodulation results after synthesis.

  The present invention has been made to solve the above-described problem, and a communication apparatus according to an aspect of the present invention includes a plurality of reception units that receive the same radio signal transmitted by a CDMA system, and the plurality of reception units. A path search unit that performs a path search using radio signals received by the unit, and generates a path search result including one or more path timings as a path search result common to the radio signals received by the plurality of receiving units; At a path timing included in the path search result, a reception signal quality acquisition unit that obtains an index value indicating reception signal quality for each of radio signals received by the plurality of reception units, and the reception signal quality acquisition unit determines the reception signal quality acquisition unit When it is determined whether the received signal quality indicated by the index value is equal to or higher than the received signal quality satisfying the predetermined condition, A mask control signal generating unit that generates a mask control signal for instructing not to use the radio signal in rake timing for rake synthesis, and a radio signal received by the plurality of receiving units at a path timing included in the path search result A radio signal processing unit that performs rake combining using a radio signal excluding a reception timing and a path timing indicated by the mask control signal.

  A received signal processing method according to an aspect of the present invention is a received signal processing method for a communication apparatus that receives a radio signal transmitted by a CDMA method, and a plurality of receiving units are transmitted by a CDMA method. A reception step of receiving the same radio signal, and a path search unit performs a path search using radio signals received by the plurality of reception units in the reception step, and the radio signals received by the plurality of reception units A path search step for generating a path search result including one or more path timings as a common path search result, and a reception signal quality acquisition unit receiving the plurality of reception units at a path timing included in the path search result A reception signal quality acquisition step for obtaining an index value indicating the reception signal quality for each radio signal to be transmitted, and a mask control signal generation unit, It is determined whether or not the received signal quality indicated by the index value obtained in step is equal to or higher than the received signal quality satisfying a predetermined condition. A mask control signal generation step for generating a mask control signal for instructing not to use the radio signal for rake combining, and the radio signal processing unit receives the plurality of reception units at a path timing included in the path search result. A radio signal processing step of performing rake combining using a radio signal excluding a received signal and a path timing indicated by the mask control signal among the radio signals.

  According to another aspect of the present invention, there is provided a program received by a plurality of reception units in a computer that performs reception signal processing of a communication apparatus including a plurality of reception units that receive the same radio signal transmitted by a CDMA system. A path search step for performing a path search using a radio signal to generate a path search result including one or more path timings as a path search result common to radio signals received by the plurality of receiving units; In the path timing included in the result, a reception signal quality acquisition step for obtaining an index value indicating reception signal quality for each of the radio signals received by the plurality of reception units, and the index obtained in the reception signal quality acquisition step It is determined whether the received signal quality indicated by the value is equal to or higher than the received signal quality that satisfies the predetermined condition, and the received signal quality that satisfies the predetermined condition If it is determined that it is full, a mask control signal generating step for generating a mask control signal for instructing not to use the radio signal at the path timing for rake synthesis, and the plurality of the timings at the path timing included in the path search result. This is a program for executing a radio signal processing step of performing rake combining using a radio signal excluding a received signal and a path timing indicated by the mask control signal among radio signals received by a receiving unit.

  According to the present invention, an increase in the number of path timings included in a path search result can be suppressed even when the communication apparatus has a plurality of receiving antennas, and the S / N ratio of the demodulation result after rake combining can be reduced. Decline can be prevented.

It is a block diagram which shows schematic structure of the communication apparatus in one Embodiment of this invention. In the embodiment, it is a figure which shows the example of the path | pass which the communication apparatus 1 selects. It is a sequence diagram which shows the process sequence of the communication apparatus 1 of the embodiment with respect to the received signal at the path timing r31 of FIG. FIG. 4 is a sequence diagram showing a processing procedure of the communication apparatus 1 according to the embodiment for a received signal at the path timing r32 in FIG. It is a sequence diagram which shows the process sequence of the communication apparatus 1 of the embodiment with respect to the received signal at the path timing r33 of FIG. It is a block diagram which shows schematic structure of the communication apparatus in the modification of this invention. It is a figure which shows the example which a communication apparatus produces | generates the path search result common to several received signals.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a configuration diagram showing a schematic configuration of a communication apparatus according to an embodiment of the present invention.
In the figure, the communication apparatus 1 includes receiving units 111 and 121, despreading units 112 and 122, transmission path estimation units 113 and 123, a path search unit 131, and a rake combining unit 141. The path search unit 131 is a specific example of a path search unit, a received signal quality acquisition unit, and a mask control signal generation unit in the present invention. Further, despreading sections 112 and 122, transmission path estimation sections 113 and 123, and rake combining section 141 together constitute a specific example of a radio signal processing section in the present invention.

Receiving sections 111 and 121 have an antenna to receive a radio signal, demodulate the received radio signal (received signal), and output the demodulated signal to path search section 131 and despreading sections 112 and 122.
The path search unit 131 performs a path search for the reception signals output from the reception units 111 and 121 to detect a path timing having a high degree of despreading correlation with a spreading code within one symbol length of time. Specifically, the path search unit 131 selects the same number (two) of path timings as the despreading units 112 and 122 included in the communication device 1 in descending order of correlation.

Then, the path search unit 131 outputs information indicating one of the two selected path timings to the despreading unit 112 as the path search result, and outputs information indicating the other path timing to the despreading unit 122. Output. For example, the path search unit 131 outputs the earlier path timing of the selected path timings to the despreading unit 112 and outputs the later path timing to the despreading unit 122.
Further, the path search unit 131 determines the high received signal quality for each of the path timings selected in the path search, and the received signal determined to have a low received signal quality is used for the rake combining performed by the rake combining unit 141. Mask control information for masking so as not to be used is output.

  Note that the timing at which the path search unit 131 performs a path search can be set in various ways. For example, each time a pilot signal is received, the path search unit 131 may perform a path search at regular intervals, or may perform a path search every symbol length, that is, every transmission symbol. May be. When a path search is performed at regular intervals, the same path timing is repeatedly used until the next path search is performed. In addition, the timing at which the path search unit 131 determines the quality of the received signal quality can be variously set in the same manner as the timing at which the path search is performed.

  The despreading unit 112 despreads the reception signal output from the receiving unit 111 based on a predetermined spreading code at the path timing indicated by the path search result output from the path search unit 131, and the despread result Is output to the transmission path estimation unit 113. At this time, the despreading unit 112 does not despread the received signal masked in the mask control information output from the path search unit 131 and does not transmit the despreading result.

  Similarly, the despreading unit 122 despreads the reception signal output from the reception unit 121 at a path timing indicated by the path search result output from the path search unit 131 based on a predetermined spreading code, The despread result is output to the transmission path estimation unit 123. At this time, the despreading unit 122 does not despread the received signal masked in the mask control information output from the path search unit 131 and does not transmit the despread result.

  The transmission path estimation unit 113 performs transmission path estimation in advance using, for example, a pilot signal included in the reception signal of the reception unit 111, and performs the despreading result output from the despreading unit 112 based on the transmission path estimation result. Correct the phase. Then, the transmission path estimation unit 113 outputs the despreading result whose phase has been corrected to the rake combining unit 141.

  Similarly, the transmission path estimation unit 123 performs transmission path estimation in advance using, for example, a pilot signal included in the reception signal of the reception section 121, and despreads output from the despreading section 122 based on the transmission path estimation result. Perform phase correction on the result. Then, the transmission path estimation unit 123 outputs the despreading result whose phase has been corrected to the rake combining unit 141.

  The rake combining unit 141 performs rake combining using the despread result whose phase is corrected, which is output from the transmission path estimation unit 113 and the transmission path estimation unit 123, and performs post-processing such as decoding on the rake combination result. Output to post-processing section.

  FIG. 2 is a diagram illustrating an example of a path selected by the communication apparatus 1. FIG. 5A shows the degree of correlation (correlation coefficient) of the despreading result by the spreading code of the received signal of the receiving unit 111, and FIG. Indicates the degree of correlation. FIG. 6C shows a path search result generated by the path search unit 131. FIG. 4D shows a path selected by the despreading unit 112, and FIG. 4E shows a path selected by the despreading unit 122.

The path search unit 131 generates a single path search result based on the two received signals output from the receiving unit 111 and the receiving unit 121.
In the example of FIG. 2, first, the path search unit 131 receives the degree of correlation of the result of despreading by the spreading code of the reception signal of the reception unit 111 (hereinafter referred to as “the degree of correlation of the reception signal”) and the reception of the reception unit 121. Sum signal correlation. The correlation degree r11 in FIG. 10A and the correlation degree r11 in FIG. 10B are the correlation degrees at the same time (path timing), and the path search unit 131 sums up these two correlation degrees. The index value r31 in the path search is set. Similarly, the path search unit 131 adds the correlation degrees r12 and r22 to an index value r32, adds the correlation degrees r13 and r23 to an index value r33, and adds the correlation degrees r14 and r24 to an index. The value is r34.

Then, the path search unit 131 selects a path timing having a large index value within a range equal to or less than the number of fingers included in the rake combining unit 141.
In the example of FIG. 2, the path search unit 131 calculates the path timing of the index value r32 (hereinafter referred to as “path timing r32”, the same applies to other index values) and the path timing r33 in descending order of the index value. Two path timings are selected. In the figure, the path timing selected by the path search unit 131 is shown as a path timing having a larger index value than the chain line. That is, the path timings r32 and r33 having a larger index value than the chain line are the path timings selected by the path search unit 131. On the other hand, path timings r31 and r34 having an index value smaller than that of the chain line are path timings not selected by the path search unit 131.

  Here, looking at the correlation of the received signal at each path timing selected by the path search unit 131, the correlation r12 of the received signal of the receiving unit 111 and the correlation of the received signal of the receiving unit 121 at the path timing r32. Each of the degrees r22 indicates a large (high) correlation degree, and by performing demodulation using the received signal at the path timing, the S / N ratio (Signal to Noize ratio) of the demodulation result can be increased. . Similarly, the correlation r13 of the reception signal of the reception unit 111 at the path timing r33 also shows a large correlation.

  On the other hand, the correlation r23 of the reception signal of the reception unit 121 at the path timing r33 indicates a small (low) correlation. This small degree of correlation indicates that the received signal of the reception unit 121 at the path timing r33 has a low S / N ratio in relation to the signal to be demodulated by the communication device 1. Therefore, when demodulation is performed using the received signal, the S / N ratio of the demodulation result becomes low.

Therefore, the path search unit 131 determines whether or not the reception quality of the reception signal in each reception unit is low at each path timing selected in the path search, and uses the reception signal determined to have low reception quality for demodulation. The mask control information for masking so as not to be output is output.
For example, in the example of FIG. 2, the path search unit 131 determines the correlation between the reception signal of the reception unit 111 and the correlation of the reception signal of the reception unit 121 for each of the path timings r32 and r33 selected in the path search. If the magnitude of the difference is equal to or greater than a predetermined threshold, it is determined that the reception quality of the received signal with the lower correlation is lower, and a mask control signal for masking the received signal is output. To do. On the other hand, if the magnitude of the difference is less than the predetermined threshold, the path search unit 131 determines that the reception quality of both reception signals is high, and does not output the mask control signal.

At the path timing r32, the correlation r12 of the reception signal of the reception unit 111 and the correlation r22 of the reception signal of the reception unit 121 are approximately the same magnitude, and the magnitude of the difference in correlation is less than the threshold. Therefore, the path search unit 131 does not output a mask control signal.
On the other hand, at the path timing r33, the correlation r23 of the reception signal of the reception unit 121 is smaller than the correlation r13 of the reception signal of the reception unit 111, and the magnitude of the correlation difference is equal to or greater than the threshold value. Therefore, the path search unit 131 generates a mask control signal for the reception signal of the reception unit 121, and outputs the mask control signal to the despreading unit 122 that processes the reception signal at the path timing r33.

As a result, the received signal to be subjected to rake synthesis by the rake synthesis unit 141 has the path timing shown in FIGS. 2 (d) and 2 (e).
In the figure, the path search unit 131 notifies the despreading unit 112 of the selected path timing r32 and does not output a mask control signal. Thereby, the despreading unit 112 performs despreading on the reception signal of the reception unit 111 and the reception signal of the reception unit 121 at the path timing r32.

On the other hand, the path search unit 131 notifies the despreading unit 122 of the selected path timing r33, and outputs a mask control signal for the reception signal of the reception unit 121. Thereby, the despreading unit 122 performs despreading on the reception signal of the reception unit 111 at the path timing r33, but does not perform despreading on the reception signal of the reception unit 121.
The rake combining unit 141 performs rake combining using the reception signal of the reception unit 111 despread at the path timings r32 and r33 and the reception signal of the reception unit 111 despread at the path timing r32. .

  Thus, since the path search unit 131 outputs a single path search result, an increase in the amount of data of the path search result can be suppressed regardless of the number of receiving units, and the control of path following is complicated. Can be prevented. In addition, since the path search unit 131 outputs the mask control signal, the rake combining unit 141 performs the rake combining using only the received signal of the path timing having the high correlation degree. A decrease in the / N ratio can be prevented.

Next, the operation of the communication device 1 will be described with reference to FIGS.
FIG. 3 is a sequence diagram showing a processing procedure of the communication apparatus 1 for a received signal at the path timing r31 in FIG. FIG. 4 is a sequence diagram showing a processing procedure of the communication apparatus 1 for a received signal at the path timing r32 in FIG. FIG. 5 is a sequence diagram showing the processing procedure of the communication apparatus 1 for the received signal at the path timing r33 in FIG.
Note that the path search unit 131 processes the received signal for each symbol length, which is a time segment including a plurality of path timings, instead of for each path timing. The flow of data during reception signal processing at one path timing is shown.

In FIG. 3, when receiving a radio signal, receiving section 111 outputs the received radio signal (received signal) to path search section 131, despreading section 112 and despreading section 122 (sequence S101). At the same time, the reception unit 121 also receives the radio signal and outputs the received signal to the path search unit 131, the despreading unit 112, and the despreading unit 122 (sequence S102).
Then, the path search unit 131 performs path search (sequence S111) and mask determination (sequence S121) based on the radio signals output from the reception unit 111 and the reception unit 121. Here, at the path timing r31, the correlation degree of the received signal is small and is not selected by the path search, and the path search unit 131 does not output information indicating the path timing. For this reason, despreading section 112 and despreading section 122 do not despread the received signal at this path timing. Therefore, the rake combining unit 141 does not use the received signal at this path timing for rake combining.

  Next, in FIG. 4, sequences S201 to S221 are the same as sequences S101 to S121 in FIG. Here, at the path timing r32, the received signal has a high degree of correlation and is selected by path search. Then, the path search unit 131 outputs information indicating the path timing r32 to the despreading unit 112 (sequence S212).

  Further, the path search unit 131 obtains the magnitude of the difference between the correlation level of the reception signal of the reception unit 111 and the correlation level of the reception signal of the reception unit 121 for the path timing r32 selected by the path search in the sequence S211. Then, mask determination is performed to determine whether the mask control signal output is necessary (sequence S221). At the path timing r32, the magnitude of the difference between the correlation r12 of the reception signal of the reception unit 111 and the correlation r22 of the reception signal of the reception unit 121 is equal to or less than a threshold value, and the path search unit 131 outputs a mask control signal. do not do.

  Upon receiving the information indicating the path timing r32 output from the path search unit 131, the despreading unit 112 despreads each of the reception signal of the reception unit 111 and the reception signal of the reception unit 121 at the path timing r32. And outputs the despread result to the transmission path estimation unit 113 (sequence S233). Then, the transmission path estimation unit 113 performs transmission using a pilot signal for each of the despread result of the reception signal of the reception unit 111 output from the despreading unit 112 and the despread result of the reception signal of the reception unit 121. Based on the path estimation result, the phase is adjusted (sequence S241), and the phase-adjusted despreading result is output to the rake combining unit 141 (sequence S243). The rake combining unit 141 performs rake combining using the phase-adjusted despreading result output from the transmission path estimation unit 113 and the phase-adjusted despreading result output from the transmission path estimation unit 123, The rake composition result is output to a part that performs post-processing such as decoding.

  Next, in FIG. 5, sequences S301 to S321 are the same as sequences S201 to S221 in FIG. Here, at the path timing r33, the degree of correlation of the received signal is large and is selected by the path search. Then, the path search unit 131 outputs information indicating the path timing r33 to the despreading unit 112 (sequence S312).

  Further, the path search unit 131 obtains the magnitude of the difference between the correlation degree of the reception signal of the reception unit 111 and the correlation level of the reception signal of the reception unit 121 for the path timing r32 selected by the path search in the sequence S311. Then, mask determination is performed to determine whether or not the mask control signal output is necessary (sequence S321). Then, at the path timing r33, it is detected that the correlation r23 of the reception signal of the reception unit 121 is smaller than the correlation r13 of the reception signal of the reception unit 111 and that the magnitude of the correlation difference is equal to or greater than the threshold. Then, a mask control signal for the reception signal of reception section 121 is generated and output to despreading section 122 (sequence S322).

The despreading unit 122 that has received the output of the information indicating the path timing r33 and the mask control signal output from the path search unit 131 performs despreading on the received signal of the receiving unit 111 at the path timing r33, and performs despreading. The result is output to transmission path estimation section 123 (sequence S334). On the other hand, according to the mask control signal, the despreading unit 122 does not despread the received signal of the receiving unit 121 and does not output the despreading result.
Then, the transmission path estimation unit 123 adjusts the phase of the despreading result of the reception signal of the reception unit 111 output from the despreading unit 122 based on the transmission path estimation result using the pilot signal (sequence S342). The phase-spread despreading result is output to rake combining unit 141 (sequence S344). The rake combining unit 141 performs rake combining using the phase-adjusted despreading result output from the transmission path estimation unit 113 and the phase-adjusted despreading result output from the transmission path estimation unit 123, The rake composition result is output to a part that performs post-processing such as decoding.

  As described above, the path search unit 131 outputs a path search result common to the reception signal of the reception unit 111 and the reception signal of the reception unit 121. Further, the path search unit 131 determines whether the received signal quality is low for each path timing determined by the path search and for each receiving unit, and determines the received signal quality is low. Mask control information for masking the received signal so that it is not used for rake synthesis.

  In this way, the path search unit outputs a common path search result to a plurality of receiving units, so that an increase in the data amount of the path search result can be suppressed regardless of the number of receiving devices included in the communication device. . In addition, when the path search unit outputs mask control information for a received signal with low received signal quality, the rake combiner 141 performs rake combining using the despreading result of the received signal with low received signal quality, and rake combining is performed. It can prevent that the S / N ratio of a result falls.

  Note that portions other than the path search unit may perform reception quality measurement for performing mask control. For example, since the rake combiner 141 also reports to the higher layer, it is necessary to measure the reception quality. Therefore, the rake combining unit 141 may perform reception quality measurement for performing mask control.

FIG. 6 is a configuration diagram showing a schematic configuration of a communication device according to a modification of the present invention. In the figure, the communication apparatus 2 includes receiving units 111 and 121, despreading units 112 and 122, transmission path estimation units 113 and 123, a path search unit 231 and a rake combining unit 241. The path search unit 131 is a specific example of the path search unit and the mask control signal generation unit in the present invention. Further, the despreading units 112 and 122, the transmission path estimation units 113 and 123, and the rake combining unit 141 are combined to constitute a radio signal processing unit in the present invention. The rake combining unit 141 is a specific example of the received signal quality acquisition unit in the present invention.
In the same figure, parts having the same functions as those in FIG. 1 are denoted by the same reference numerals (111 to 113, 121 to 123), and description thereof is omitted.

  The path search unit 231 receives the output of the information indicating the quality measurement result from the rake combining unit 241, and determines whether to mask the received signal so that it is not used for demodulation for each path timing and for each receiving unit. And the mask control information is output to the despreading unit 112 or the despreading unit 122 based on the mask determination result.

  At this time, for example, a channel that is predetermined as a channel used by the rake combining unit 241 for reception quality measurement, such as a channel through which a pilot signal is transmitted, is excluded from masking targets. As a result, the despreading result of the channel is output to the rake combining unit 241 (after phase correction), and the rake combining unit 241 can perform quality measurement based on the despreading result.

  Similarly to the rake combining unit 141 in FIG. 1, the rake combining unit 241 performs rake combining using the despread results whose phases are corrected, which are output from the transmission path estimating units 113 and 123, and performs post-processing such as decoding. The rake composition result is output to the part to be performed. In addition, the rake combining unit performs quality measurement on a predetermined channel based on the despread result whose phase output from the transmission path estimation units 113 and 114 is corrected, and sends the quality measurement result to the path search unit 231. Output.

  Thus, since the rake combining unit 241 outputs the reception quality measurement result to the path search unit 231, the path search unit 231 does not need to perform reception quality measurement in order to determine whether or not to output mask control information. In this respect, the configuration of the path search unit can be simplified and power consumption can be suppressed.

A program for realizing all or part of the functions of the communication device 1 or the communication device 2 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed. By doing so, you may process each part. Here, the “computer system” includes an OS and hardware such as peripheral devices.
Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like without departing from the gist of the present invention.

1, 2 Communication device 111, 121 Receiving unit 112, 122 Despreading unit 113, 123 Transmission path estimation unit 131, 231 Path search unit 141, 241 Rake combining unit

Claims (4)

A plurality of receiving units for receiving the same radio signal transmitted by the CDMA method;
A path that performs a path search using radio signals received by the plurality of receiving units and generates a path search result including one or more path timings as a path search result common to the radio signals received by the plurality of receiving units. A search section;
A reception signal quality acquisition unit for obtaining an index value indicating reception signal quality for each of radio signals received by the plurality of reception units at a path timing included in the path search result;
When it is determined whether the received signal quality indicated by the index value obtained by the received signal quality acquisition unit is equal to or higher than the received signal quality that satisfies a predetermined condition, A mask control signal generation unit that generates a mask control signal instructing not to use the wireless signal in the path timing for rake combining;
A radio signal processing unit that performs rake combining using a radio signal that excludes a received signal and a path timing indicated by the mask control signal among radio signals received by the plurality of receiving units at a path timing included in the path search result When,
A communication apparatus comprising: The reception signal quality acquisition unit obtains reception signal quality at a predetermined timing for radio signals received by the plurality of reception units,
The communication apparatus according to claim 1, wherein the mask control signal generation unit suppresses generation of the mask control signal at the predetermined timing. A received signal processing method of a communication apparatus that receives a radio signal transmitted by a CDMA method,
A receiving step in which a plurality of receiving units receive the same radio signal transmitted by the CDMA method;
A path search unit performs a path search using radio signals received by the plurality of reception units in the reception step, and one or more paths are obtained as a path search result common to the radio signals received by the plurality of reception units. A path search step for generating a path search result including timing;
A reception signal quality acquisition unit that obtains an index value indicating reception signal quality for each of radio signals received by the plurality of reception units at a path timing included in the path search result; and
The mask control signal generation unit determines whether or not the received signal quality indicated by the index value obtained in the received signal quality acquisition step is equal to or higher than the received signal quality that satisfies a predetermined condition, and the received signal that satisfies the predetermined condition If it is determined that the quality is less than the quality, a mask control signal generation step for generating a mask control signal instructing not to use the radio signal at the path timing for rake combining;
A radio signal processing unit performs rake combining using a radio signal excluding a received signal and a path timing indicated by the mask control signal among radio signals received by the plurality of receiving units at a path timing included in the path search result. A radio signal processing step for performing
A received signal processing method. In a computer that performs reception signal processing of a communication device including a plurality of reception units that receive the same wireless signal transmitted by the CDMA method,
A path that performs a path search using radio signals received by the plurality of receiving units and generates a path search result including one or more path timings as a path search result common to the radio signals received by the plurality of receiving units. A search step;
A reception signal quality acquisition step for obtaining an index value indicating reception signal quality for each of radio signals received by the plurality of reception units at a path timing included in the path search result;
When it is determined whether the received signal quality indicated by the index value obtained in the received signal quality acquisition step is equal to or higher than the received signal quality that satisfies a predetermined condition, and it is determined that the received signal quality is less than the received signal quality that satisfies the predetermined condition A mask control signal generating step for generating a mask control signal for instructing not to use the radio signal at the path timing for rake synthesis;
Radio signal processing step for performing rake combining using a radio signal excluding a received signal and a path timing indicated by the mask control signal among radio signals received by the plurality of receiving units at a path timing included in the path search result When,
A program for running

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