JP2006094215A - Radio communication receiving set - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the receiving performance of a radio communication receiving set in a CDMA (Code Division Multiple Access) communication system, while reducing its throughput. <P>SOLUTION: An estimation means 105 estimates the conditions of existence of a plurality of paths on the basis of a received signal. A rake combining means 117 performs rake processing of transmission path estimation, phase amplitude correction, and back diffusion processing for each signal corresponding to each path, and combines a plurality of signals whose rake processing has been performed. A frequency equalizing means 118 performs frequency equalizing processing for a signal being a received signal whose Fourier transformation has been performed, and back diffusion processing is performed for the processed signal. An operation selection means 105 allows either the rake combining means or the frequency equalization means to operate, based on the conditions of existence of the plurality of paths. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wireless communication receiving apparatus in a wireless communication system, and more particularly to a wireless communication receiving apparatus in a CDMA (Code Division Multiple Access) communication system.

  In a conventional CDMA wireless communication receiver, a path diversity gain is obtained by performing a multipath search, assigning a rake finger to the estimated path, and performing rake combining.

In recent CDMA wireless communication receivers, a method of canceling interference due to a path using frequency equalization for broadband CDMA wireless communication has also been proposed (for example, Non-Patent Document 1).
F. Adachi, T. Sao, and T. Itagaki, “Performance of multicode DS-CDMA using frequency domain equalization in a frequency selective fading channel,” Electronics Letters, Vol. 39, pp.239-241, Jan. 2003.

However, in the case of a CDMA wireless communication receiving apparatus that performs rake combining, there is a limit to the number of fingers that can be processed, so when multipaths that exceed the number of fingers arrive, reception performance degradation due to multipath interference becomes a problem. .
In addition, in the case of a CDMA wireless communication receiving apparatus that performs frequency equalization, when the number of incoming multipaths is small, the reception performance is equivalent to that of rake combining, but there is a problem that the processing amount increases. Furthermore, frequency equalization also has a problem that reception performance is significantly degraded when there are multipaths exceeding the guard interval.
In addition, reduction of power consumption of the wireless communication receiver and improvement of reception performance are issues.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a wireless communication receiving apparatus with high reception performance while reducing the processing amount.

  According to the wireless communication receiving apparatus of the present invention, in the wireless communication receiving apparatus in the code division multiple access (CDMA) system, the estimation means for estimating the presence of a plurality of paths based on the received signal, Rake combining means that performs rake processing of transmission path estimation, phase amplitude compensation, and despreading processing for each signal corresponding to the path, and synthesizes a plurality of rake-processed signals, and a frequency obtained by Fourier-transforming the received signal Frequency equalization means that performs equalization processing and despread processing on the processed signal, and operates either one of the rake combining means and the frequency equalization means based on the presence status of the plurality of paths It is characterized by comprising operating means.

  According to the wireless communication receiver of the present invention, it is possible to improve reception performance while reducing the processing amount.

Hereinafter, a wireless communication receiver according to an embodiment of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, the wireless communication receiver of this embodiment includes a radio frequency processing unit (RF) 101, a digital / analog conversion processing unit (DAC) 102, a band-pass filter processing unit (BPF) 103, and a correlation value calculation. Processing unit (Correlator) 104, multipath estimation processing / equalization method selection processing unit (Multi-path Estimator) 105, path threshold control processing unit (Threshold Controller) 106, spreading code generation processing unit (Code Generator) 110, pilot signal A generation processing unit (Pilot) 107, an error correction processing unit (Error Collect) 115, a rake synthesis processing unit 117, a frequency equalization processing unit 118, and switches 119 and 120 are provided.
The radio frequency processing unit 101 inputs a CDMA signal received by an antenna and performs frequency conversion processing to an analog baseband frequency signal. The digital / analog conversion processing unit 102 receives the output signal of the radio frequency processing unit 101 and converts it into a digital signal. The band pass filter processing unit 103 filters only a signal in a certain band.

The pilot signal generation processing unit 107 generates a pilot signal. This pilot signal is a known signal that the receiving side knows in advance what kind of signal is transmitted from the transmitting side, and is usually notified from an upper layer.
Correlation value calculation processing section 104 calculates a cross-correlation value between the output signal of bandpass filter processing section 103 and the output signal of pilot signal generation processing section 107, and outputs the calculation result. Correlation value calculation processing section 104 may average the cross-correlation values calculated in a predetermined period and output the averaged calculation result as an output signal.
The multipath estimation processing / equalization method selection processing unit 105 compares the cross-correlation value (hereinafter referred to as correlation value) from the correlation value calculation processing unit 104 with the path threshold value from the path threshold value control processing unit 106, and It is estimated that a path exists at a time having a correlation value exceeding the path threshold. Further, the multipath estimation processing / equalization method selection processing unit 105 uses the rake combining processing unit 117 or the frequency equalization processing unit 118 for the equalization method of the wireless communication receiving apparatus according to the estimated multipath situation. Select whether to use. Specific selection criteria will be described later with reference to FIG.

  When the multipath estimation processing / equalization method selection processing unit 105 determines to select the rake combining processing unit 117, the multipath estimation processing / equalization method selection processing unit 105 outputs a signal for switching the switches 119 and 120 to the A side to the switches 119 and 120, The processing unit 117 is turned on, and the frequency equalization processing unit 118 is turned off. On the other hand, when the multipath estimation processing / equalization method selection processing unit 105 determines to select the frequency equalization processing unit 118, the multipath estimation processing / equalization method selection processing unit 105 outputs a signal for switching the switches 119 and 120 to the B side to the switches 119 and 120. The synthesis processing unit 117 is turned off, and the frequency equalization processing unit 118 is turned on.

  The path threshold value control processing unit 106 sets a path threshold value that is a criterion for determining whether or not a multipath exists, and outputs it to the multipath estimation processing / equalization method selection processing unit 105. The path threshold control processing unit 106 may change the path threshold according to the situation. Possible triggers for the path threshold control processing unit 106 to change the path threshold include the remaining battery level, the QoS of the service being communicated, the distinction between communication and standby, the error rate of the decoding result, and the like. Details of the path threshold value control processing unit 106 changing the path threshold value will be described later with reference to FIG. 6 or FIG.

  The switches 119 and 120 switch the switches to the A side or the B side according to an instruction from the multipath estimation processing / equalization method selection processing unit 105.

  The spreading code generation processing unit 110 generates a spreading code for despreading processing. The error correction processing unit 115 performs error correction processing on the output signal of the rake synthesis processing unit 117 or the frequency equalization processing unit 118.

  The rake combining processing unit 117 inputs the normal path status information estimated by the multipath estimation processing / equalization method selection processing unit 105 and the output signal of the bandpass filter processing unit 103, and corresponds to the path. Transmission path estimation and phase / amplitude compensation are performed for each signal. Further, the rake synthesis processing unit 117 receives the spreading code from the spreading code generation processing unit 110 and performs despreading processing for each signal corresponding to the path.

  The frequency equalization processing unit 118 receives the output signal of the band pass filter processing unit 103, performs a Fourier transform, performs a frequency equalization process, and performs an inverse Fourier transform. Thereafter, the spreading code is input from the spreading code generation processing unit 110, and the despreading process is performed on the signal after the inverse Fourier transform.

  The rake synthesis processing unit 117 includes a plurality of finger processing units (Rake Finger) 108, a synthesis unit (Rake Combiner) 109, and a multi-path assignment processing unit (Multi-path Assign) 116. A frequency equalization processing unit 118 A conversion processing unit (FFT) 111, a frequency equalization processing unit (FDE) 112, an inverse Fourier transform processing unit (IFFT) 113, and a despreading processing unit 114 are provided.

The multipath assignment processing unit 116 determines a path to be assigned to each finger processing unit 108 based on the status information of the normal plurality of paths estimated by the multipath estimation processing / equalization method selection processing unit 105.
Each finger processing unit 108 receives the output signal of the bandpass filter processing unit 103 and performs transmission path estimation and phase / amplitude compensation on the signal of the path allocated to the multipath allocation processing unit 116. Further, the finger processing unit 108 receives the spreading code from the spreading code generation processing unit 110 and performs despreading processing on the signal of the path assigned to the multipath assignment processing unit 116.
The synthesizer 109 receives the output signals from each finger processor 108, synthesizes these signals, and outputs a synthesized signal.

The Fourier transform processing unit 111 receives the output signal of the bandpass filter processing unit 103 and converts this signal into a signal on the frequency axis.
The frequency equalization processing unit 112 performs transmission path estimation and phase / amplitude compensation on the output signal of the Fourier transform processing unit 111 for each frequency.
The inverse Fourier transform processing unit 113 converts the output signal of the frequency equalization processing unit 112 into a signal on the time axis.
The despreading processing unit 114 receives the spreading code from the spreading code generation processing unit 110 and performs a despreading process.

  Next, an example of estimation processing and selection processing in the multipath estimation processing / equalization method selection processing unit 105 will be described with reference to FIGS.

The multipath estimation processing / equalization method selection processing unit 105 compares the signal output from the correlation value calculation processing unit 104 with the path threshold value output from the path threshold value control processing unit 106 to determine whether a multipath exists. Determine. In the example illustrated in FIG. 2, the correlation value (corresponding to the power of the path) between the path 201 and the path 202 exceeds the path threshold value. In this example, the number of paths is 2.
Furthermore, the multipath estimation processing / equalization method selection processing unit 105 uses the rake synthesis processing unit 117 or the frequency equalization processing unit 118 for the receiver equalization method according to the estimated multipath situation. Select.

As a specific selection criterion, there is a case where selection is made based on whether or not the number of paths estimated within a certain time is smaller than a predetermined number. Here, N _{Finger_Max} is _set to the maximum number of paths that the multipath assignment processing unit 116 can assign to the finger processing unit 108. That is, N _{Finger_Max} is the number of finger processing units 108.
When the number of paths estimated by the multipath estimation processing / equalization method selection processing unit 105 is smaller than N _{Finger_Max, the} rake synthesis processing unit 117 is selected. On the other hand, when the estimated number of paths is not smaller than N _{Finger_Max} Selects the frequency equalization processing unit 118. For example, in the situation of the example shown in FIG. 2, if N _{Finger_Max} = 4, since there are two correlation values estimated as paths, the multipath estimation processing / equalization method selection processing unit 105 performs rake synthesis. The processing unit 117 is selected.

The processing amount in the rake synthesis processing unit 117 is smaller than the processing amount in the frequency equalization processing unit 118. Therefore, as described above, frequency equalization is performed when the number of estimated paths is large to suppress reception performance degradation due to multipath interference, and rake combining processing is performed when the number of multipaths is small. Therefore, it is possible to reduce the amount of processing required for the equalization processing.
In general, when rake combining processing is performed, multipath power (correlation value) is measured using a correlation value between a received signal and a pilot signal, and each path is assigned to the finger processing unit 108 using the value. . As described above, by switching the equalization method using the estimated multipath power information, the processing can be shared, and the increase in the processing amount of the entire reception processing can be suppressed.

On the other hand, in the example shown in FIG. 3, five paths from the path 301 to the path 305 have a correlation value larger than the path threshold value. As in the case of FIG. 2, if N _{Finger_Max} = 4, the number of paths is larger than N _{Finger_Max} , so the multipath estimation processing / equalization method selection processing unit 105 selects the frequency equalization processing unit 118. To do.

  If the number of paths estimated by the rake synthesis processing unit 117 is larger than the number of finger processing units 108, and the rake synthesis processing unit 117 performs rake synthesis, the paths that could not be assigned to the finger processing unit 108 The multipath estimation processing / equalization method selection processing unit 105 selects the frequency equalization processing unit 118 because reception performance deteriorates due to interference.

Next, another example of selection processing in the multipath estimation processing / equalization method selection processing unit 105 will be described with reference to FIGS.
In this example, the equalization method selection method uses the frequency equalization processing unit when the time between the first path and the last path among the estimated paths is longer than the guard interval. This is based on the fact that the performance of 118 greatly deteriorates. In order to prevent this, multipath estimation processing / equalization method selection is selected when the time between the first path and the last path among the estimated paths is longer than the guard interval. The processing unit 105 can improve the reception performance by selecting the rake combining processing unit 117. On the other hand, when the time between the first path and the last path among the estimated paths is equal to or shorter than the guard interval, the frequency equalization processing unit 118 is selected. In the case of such a relationship between the path time and the guard interval, sufficient reception performance can be obtained by the frequency equalization processing unit 118. That is, the multipath estimation processing / equalization method selection processing unit 105 selects an equalization method by comparing a period in which a plurality of paths exist and the length of the guard interval.

  In the example of FIG. 4, the multipath estimation processing / equalization method selection processing unit 105 determines that the time between the first path 401 and the last path 403 among the estimated paths is Since it is shorter than the guard interval, the frequency equalization processing unit 118 is selected.

  In the example of FIG. 5, the multipath estimation processing / equalization method selection processing unit 105 determines that the time between the first path 501 and the last path 503 among the estimated paths is as follows. Since it is longer than the guard interval, the rake composition processing unit 117 is selected.

In general, in a CDMA reception system that performs frequency equalization, a transmission signal is divided into a certain number of blocks (several symbols), and the first few chips of each block are added after each block, which is used as a guard interval. Create a transmission signal. At this time, the delay time of multipath, the added, if T _GI is greater than the time of the guard interval of the transmission signal, the reception processing using frequency equalization is generally known that the performance degradation Yes. Therefore, if the multipath delay time is larger than T _GI, by switching the rake receiver, it is possible to prevent degradation of reception performance due to the spread of the multipath delay time.

Next, a method in which the path threshold control processing unit 106 changes the path threshold according to the situation will be described with reference to FIGS. 6 and 7.
Examples of triggers for the path threshold control processing unit 106 to change the path threshold include the remaining battery level, the QoS of the service being communicated, the distinction between communication and standby, and the error rate of the decoding result. .

(Whether or not you are communicating)
When distinguishing whether the trigger is communicating or waiting, the path threshold value control processing unit 106 increases the path threshold value during standby and decreases the path threshold value during communication. If the path threshold is set high during standby, the number of paths determined as shown in FIG. 6 is reduced. For this reason, since the number of paths determined as paths is relatively reduced, the multipath estimation processing / equalization method selection processing unit 105 can easily select the rake synthesis processing unit 117. Since the rake combining processing unit 117 has a smaller processing amount than the frequency equalization processing unit 118, it is possible to reduce power consumption in the standby wireless communication receiving apparatus.
Also, if the path threshold is set low during communication, more paths are determined as shown in FIG. 7 even in the same environment as in FIG. For this reason, since the number of paths that are relatively determined is increased, the multipath estimation processing / equalization method selection processing unit 105 can easily select the frequency equalization processing unit 118. Since the frequency equalization processing unit 118 is more resistant to interference due to an increase in multipath than the rake combining processing unit 117, it is possible to improve reception performance in the wireless communication reception device. By performing the processing as described above, the wireless communication receiving apparatus of the present embodiment can reduce the processing amount during standby and can improve the reception performance during communication.

(Whether the battery level is low)
If the trigger indicates whether the remaining battery level is low, the path threshold value control processing unit 106 sets a higher path threshold value as shown in FIG. As long as it does not exist, the multipath estimation processing / equalization method selection processing unit 105 is less likely to be determined as a path. Since the number of paths recognized as paths is relatively small, the multipath estimation processing / equalization method selection processing unit 105 can easily select the rake synthesis processing unit 117. In this case, although the communication quality causes some deterioration, low power consumption can be realized.
If the remaining battery level is large and the remaining battery level is sufficient, the multipath estimation processing / equalization method selection processing unit 105 determines that the path is low by setting the path threshold value low as shown in FIG. More to do. Since the number of paths recognized as paths is relatively large, the multipath estimation processing / equalization method selection processing unit 105 can easily select the frequency equalization processing unit 118. In this case, although the frequency equalization processing unit 118 consumes a large amount of power, it is more resistant to interference due to an increase in multipath than the rake combining processing unit 117, so that the reception performance at the receiver can be improved. By performing the processing as described above, the wireless communication receiving apparatus according to the present embodiment can reduce power consumption when the remaining battery level is low, and can improve reception performance when the remaining battery level is high. be able to.

(Whether the service QoS during communication is low)
When the trigger is that the QoS (required quality) of the service being communicated is low, the path threshold value control processing unit 106 increases the path threshold value when the QoS is low and sets the path threshold value when the QoS is high. make low. If the path threshold is set high when the QoS is low, the number of paths determined as shown in FIG. 6 is reduced. For this reason, since the number of paths determined as paths is relatively reduced, the multipath estimation processing / equalization method selection processing unit 105 can easily select the rake synthesis processing unit 117. In this case, although the communication quality causes some deterioration, low power consumption can be realized.
Also, if the path threshold is set low when QoS is high, more paths are determined as shown in FIG. For this reason, since the number of paths that are relatively determined is increased, the multipath estimation processing / equalization method selection processing unit 105 can easily select the frequency equalization processing unit 118. In this case, the power consumption is large, but the reception performance can be improved. By performing the processing as described above, the wireless communication receiving apparatus according to the present embodiment can reduce power consumption in the receiver during communication of a service with a low QoS as a required quality, and a service with a high QoS can be achieved. During communication, it is possible to improve reception performance at the receiver.

(Whether the error rate of the decoding result is low)
If the error rate of the decoding result is high during rake reception, one of the causes is interference due to small multipaths not assigned to the finger processing unit 108. Further, in frequency equalization, deterioration due to interference due to a small multipath does not occur. Based on this scientific fact, when the trigger is whether the error rate of the decoding result is low, the path threshold value control processing unit 106 increases the path threshold value when the error rate is low, and the error rate is not low. Lowers the path threshold. If the path threshold is set high when the error rate is low, the number of paths determined as shown in FIG. 6 is reduced. For this reason, since the number of paths determined as paths is relatively reduced, the multipath estimation processing / equalization method selection processing unit 105 can easily select the rake synthesis processing unit 117. In this case, although the communication quality causes some deterioration, low power consumption can be realized.
Also, if the path threshold is set low when the error rate is high, more paths are determined as shown in FIG. For this reason, since the number of paths that are relatively determined is increased, the multipath estimation processing / equalization method selection processing unit 105 can easily select the frequency equalization processing unit 118. In this case, the power consumption is large, but the reception performance can be improved. By performing the processing as described above, the radio communication receiving apparatus of the present embodiment can reduce power consumption when the error rate is low, and improve reception performance when the error rate is high. be able to.

Next, the operation of the wireless communication receiving apparatus in FIG. 1 will be described with reference to FIG. 8 focusing on the operation of the multipath estimation processing / equalization method selection processing unit 105.
The path threshold value control processing unit 106 determines whether or not the wireless communication receiving apparatus is currently communicating from the higher layer (Step S801). If the communication is in progress, the process proceeds to step S802. On the other hand, if the communication is not in progress, the process proceeds to step S803.
In step S802, the path threshold control processing unit 106 sets the path threshold low, and in step S803, the path threshold control processing unit 106 sets the path threshold high. The degree to which the path threshold is lowered or raised is determined by the performance of the rake synthesis processing unit 117 and the frequency equalization processing unit 118, for example. Further, it may be determined based on the performance of the other device portion.

  Correlation value calculation processing section 104 calculates a correlation value between the output signal of bandpass filter processing section 103 and the output signal of pilot signal generation processing section 107, and outputs the calculation result (step S804). The time when the multipath estimation processing / equalization method selection processing unit 105 has a correlation value exceeding the path threshold by comparing the correlation value calculated in step S804 with the path threshold set in step S802 or S803. The number of paths is estimated on the assumption that there are paths in step S805.

The number of paths estimated by the multipath estimation processing / equalization method selection processing unit 105 in step S805 is the maximum number of paths that the multipath allocation processing unit 116 can allocate to the finger processing unit 108. N _It is determined whether or not it is larger than _{Finger_Max} (maximum number of fingers) (step S806). If it is larger than N _{Finger_Max} , the process proceeds to step S807. If it is not larger than N _{Finger_Max} , the process proceeds to step S808.

  In step S807, the multipath estimation processing / equalization method selection processing unit 105 selects the frequency equalization processing unit 118 in order to equalize the output signal of the bandpass filter processing unit 103, and switches 119 and 120 on the B side. Are output to the switches 119 and 120, the power of the rake synthesis processing unit 117 is turned off, and the power of the frequency equalization processing unit 118 is turned on.

  In step S808, the multipath estimation processing / equalization method selection processing unit 105 selects the rake synthesis processing unit 117 to equalize the output signal of the bandpass filter processing unit 103, and switches 119 and 120 to the A side. A signal to be switched is output to the switches 119 and 120, the power of the rake synthesis processing unit 117 is turned on, and the power of the frequency equalization processing unit 118 is turned off.

In the example shown in FIG. 8, the path threshold value change trigger in step S801 is “communication / standby”, and the equalization method selection trigger in step S806 is “comparison of the estimated number of paths and the number of rake fingers”. There are other triggers, though. As described above with reference to FIGS. 6 and 7, the path threshold value change trigger includes whether the remaining battery level is low, whether the QoS of the service being communicated is low, and the error rate of the decoding result is The path threshold value may be set based on whether or not it is low.
As described above with reference to FIGS. 4 and 5, the equalization method selection trigger is the first position in time among the paths estimated by the multipath estimation processing / equalization method selection processing unit 105. Whether to select the rake synthesis processing unit 117 or the frequency equalization processing unit 118 according to whether or not the time between the path to be performed and the path located at the end is longer than the guard interval. May be. Further, the selection method based on the guard interval and the selection method based on the maximum number of fingers may be combined.

  According to the embodiments described above, the rake combining processing unit and the frequency equalization processing unit are switched according to the multipath state caused by the state of the propagation path between the wireless communication transmitting device and the wireless communication receiving device. Thus, it becomes possible to select an optimal equalization method according to the transmission path, and it is possible to realize a CDMA wireless communication receiver with high reception characteristics and low throughput.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

1 is a block diagram of a wireless communication receiving device according to an embodiment of the present invention. The figure which shows the example with comparatively few multipaths by comparing the correlation value of the correlation value calculation process part of FIG. 1, and the path threshold value of the path threshold value control process part. The figure which shows the example with comparatively many multipaths by comparing the correlation value of the correlation value calculation process part of FIG. 1, and the path threshold value of the path threshold value control process part. The figure which shows the example in which the time spread of a multipath is smaller than the length of a guard interval. The figure which shows the example whose time spread of a multipath is larger than the length of a guard interval. The figure which shows the case where the path threshold value control process part 106 of FIG. 1 sets a path threshold value high, and reduces the number of paths. The figure which shows the case where the path threshold value control process part 106 of FIG. 1 sets a path threshold value low, and increased the number of paths. The flowchart which shows operation | movement of the radio | wireless communication receiver of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Radio frequency processing part (RF), 102 ... Digital-analog conversion processing part (DAC), 103 ... Band pass filter processing part (BPF), 104 ... Correlation value calculation processing part (Correlator ), 105... Multipath estimation processing / equalization method selection processing unit (Multi-path Estimator), 106... Path threshold control processing unit (Threshold Controller), 107... Pilot signal generation processing unit (Pilot) , 108 ... finger processing unit (Rake Finger), 109 ... synthesis unit (Rake Combiner), 110 ... spread code generation processing unit (Code Generator), 111 ... Fourier transform processing unit (FFT), 112 ... Frequency equalization processing unit (FDE), 113 ... Inverse Fourier transform processing unit (IFFT), 114 ... Despreading processing unit, 115 ... Correction processing unit, 116 ... Multipath allocation This Processing unit (Multi-path Assign), 117 ··· rake combining unit, 118 ... frequency equalization processing section, 119, 120 ... switch

Claims (10)

In a wireless communication receiver in a code division multiple access (CDMA) system,
Estimating means for estimating the presence of a plurality of paths based on a received signal;
Rake combining means for performing a rake process of transmission path estimation, phase amplitude compensation, and despreading processing for each signal corresponding to each path, and combining a plurality of rake processed signals;
Frequency equalization means for performing frequency equalization processing on a signal obtained by Fourier transforming the received signal, and performing despreading processing on the processed signal;
An apparatus for receiving wireless communication, comprising: operating means for operating one of the rake combining means and the frequency equalizing means based on the presence status of the plurality of paths. The rake combining means includes
A plurality of rake means for performing the rake process on each of the signals;
Assigning means for assigning each said signal to each said rake means;
Comprising combining means for combining the outputs of the rake means;
The frequency equalization means includes
Transform means for Fourier transforming the received signal into a signal on the frequency axis;
Equalization processing means for performing equalization processing on the Fourier transformed signal;
Inverse transform means for inverse Fourier transforming the equalized signal to a signal on the time axis;
The radio communication receiving apparatus according to claim 1, further comprising despreading means for performing despreading processing on the signal subjected to the inverse Fourier transform. The estimating means estimates a period in which the plurality of paths exist;
The operating means operates the rake combining means when the period is longer than the guard interval time of the received signal, and the frequency equalization when the period is equal to or shorter than the guard interval time of the received signal. The wireless communication receiving apparatus according to claim 1 or 2, wherein the means is operated. The estimating means estimates the number of the plurality of paths;
3. The wireless communication according to claim 1, wherein the operation unit operates one of the rake combining unit and the frequency equalizing unit according to the number of the plurality of paths. 4. Receiver device.   The operating means operates the frequency equalizing means when the number of the plurality of paths is larger than the number that can be rake processed, and when the number of the plurality of paths is equal to or less than the number that can be rake processed. The wireless communication receiving apparatus according to claim 4, wherein the rake combining means is operated.   6. The radio communication receiving apparatus according to claim 1, wherein the estimating unit estimates the presence state of the path based on a correlation value between the received signal and a pilot signal. 7. . The estimation means includes
Recognition means for recognizing that a path exists when the correlation value is greater than a certain threshold;
Threshold value changing means is provided for increasing the threshold value when the remaining battery level of the wireless communication receiver is less than a certain amount and decreasing the threshold value when the remaining battery level is greater than the certain amount. The wireless communication receiver according to claim 6. The estimation means includes
Recognition means for recognizing that a path exists when the correlation value is greater than a certain threshold;
Characterized by comprising threshold changing means for increasing the threshold when a required quality of a service during communication is lower than a certain quality, and decreasing the threshold when the required quality is higher than the certain quality. The wireless communication receiver according to claim 6. The estimation means includes
Recognition means for recognizing that a path exists when the correlation value is greater than a certain threshold;
The wireless communication receiving apparatus according to claim 6, further comprising a threshold value changing unit that increases the threshold value when a standby process is performed and decreases the threshold value when a communication process is performed. The estimation means includes
Recognition means for recognizing that a path exists when the correlation value is greater than a certain threshold;
The wireless communication receiving apparatus according to claim 6, further comprising threshold changing means for increasing the threshold when an error rate of the decoding result is high and decreasing the threshold when the error rate of the decoding result is low. .

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