JP2009152767A - Radio signal reception device and radio signal reception method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio signal reception device which allows all transmission stations to succeed in demodulation, without having to depend on the packet length, and irrespective of the combination of received signals of a receiving antenna. <P>SOLUTION: Radio reception units 1-2-1 to 1-2-N convert respective radio signals 1 to N, received by N units of receiving antennas 1-1-1 to 1-1-N to N units of base band signals 1 to N by frequency conversion. Extraction means 1-3 extracts M<SB>i</SB>units of signal combinations for respective M<SB>1</SB>, M<SB>2</SB>, ..., M<SB>K</SB>from among N units of base band signals 1 to N. Demodulation means 1-4 performs single demodulation when M<SB>i</SB>=1 (1≤i≤K) and perform M<SB>i</SB>(1≤i≤K) branch-receiving diversity demodulation for M<SB>i</SB>≥2 (1≤i≤K), with respect to signal sequence of combination of respective M<SB>1</SB>, M<SB>2</SB>, ..., M<SB>K</SB>units of signals. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a radio signal receiving apparatus and a radio signal receiving method including a plurality of receiving antennas.

  Conventionally, as a technique for improving the location rate characteristics in wireless transmission systems, the reception signal is successfully demodulated by installing a plurality of receiving antennas on the wireless signal receiving device side apart from each other and receiving a plurality of wireless signals at different locations. There are reception diversity techniques that increase the probability. In particular, the maximum ratio combination (MRC) that achieves the best characteristics among the reception diversity techniques is the reception signal of a plurality of antennas even when the reception level is insufficient with each reception antenna alone and the demodulation of the reception signal is difficult. May be made demodulatable by superimposing them with weights corresponding to SNR (Signal-to-Noise Ratio). Since the demodulation success rate increases as the number of antennas increases, MRC is normally performed on the received signals of all installed reception antennas unless there is a particular problem with the load of arithmetic processing (non-patent document). 1).

  In MRC, when a received signal is synthesized before detection, weighting in proportion to the envelope level of the received signal is performed so as to increase the contribution as the envelope level increases, so that the CNR of the synthesized received wave is maximized. A great combined reception effect can be expected.

  FIG. 8 is a block diagram showing a schematic configuration of a conventional radio signal reception wave position (reception diversity is performed using all reception antennas). Each of the radio signals # 1 to #N received by the N reception antennas 3-1 to 1-3-N is transmitted to the frequency by the N radio reception units 3-2-1 to 3-2-N. By conversion, N baseband signals # 1 to #N are converted. Next, N branch reception diversity demodulation means 3-3 performs N branch reception diversity demodulation on the signal sequence extracted from the N baseband signals # 1 to #N.

  However, among the reception diversity technologies, when using the site reception diversity technology that installs the receiving antennas far away from each other so that the receiving antennas are not blocked by the same shielding object, When MRC is performed, the following problems occur.

  In the site reception diversity technology, one receiving antenna is installed at a plurality of points distant from each other. Therefore, a transmitting station is close to a receiving antenna at a certain point, and a receiving antenna at another point is a separate antenna. In the case where the transmitter station is in a short distance, that is, only the radio signal of one transmitter station is received by the receive antenna at a certain point, and only the radio signal of another transmitter station is received by the receive antenna at another point. Cases occur with high probability.

  In this case, when each transmitting station transmits radio signals simultaneously by random access or the like, if MRC is performed only with the received signals of the receiving antennas at each point, all radio signals of each transmitting station can be demodulated, but all reception is possible. As a result of combining the reception signals of the antennas with the MRC, that is, the reception signals of all the reception antennas, in the combined signal, the reception signal level from one transmission station and the reception signal level from another transmission station are the same level. In this case, a situation occurs in which the signals from each other interfere with each other and the radio signal of any transmitting station cannot be demodulated.

  Even when the received signal level of a certain transmitting station is higher than the received signal level difference of another transmitting station so that it can be demodulated, only the radio signal of that transmitting station can be demodulated. The signal cannot be demodulated. In other words, when a receiving station applies site reception diversity technology and a plurality of transmitting stations transmit radio signals simultaneously by random access or the like, MRC is performed on the received signals of all receiving antennas, thereby receiving antennas at each point. There is a problem that a case in which the number of transmission stations successfully demodulated is reduced with higher probability than when MRC is performed using only the received signals.

  In addition to the MRC, the reception diversity includes selection diversity for selecting a reception signal having the maximum reception level from the reception signals of the respective reception antennas (see Non-Patent Document 2). Similar to MRC, when multiple transmission stations transmit at the same time when site reception diversity is applied, if selection diversity is performed using all reception antennas, selection diversity is performed using only reception signals of reception antennas at each point. In addition, there is a high probability that the number of transmitting stations that succeed in demodulation decreases.

  Note that there is an adaptive array technique as a technique for demodulating a radio signal of each transmitting station by providing a plurality of antennas on the receiving apparatus side when there are a plurality of transmitting stations that simultaneously transmit a radio signal. The adaptive array technology is considered a kind of diversity technology. Specifically, for each transmitting station, the MMSE weight based on the MMSE (Minimum Mean Square Error) standard is combined by weighting the received signal of each receiving antenna, thereby successfully demodulating the radio signal of each transmitting station. Probability can be maximized.

  The MMSE adaptive array technology is a system that determines an optimum weight by minimizing a difference (error signal) between a reference signal that is a desired array response and an actual array output signal. This method has the advantage that adaptive beam forming is performed simultaneously with adaptive null steering, and thus there is an advantage that the element arrangement and the system configuration are not restricted. . Actually, since there is prior knowledge about the nature (frequency band, modulation scheme, etc.) of the desired signal, an appropriate reference signal can be obtained by appropriately processing the array output signal.

  However, in order to realize the MMSE weight on the receiving station side, it is necessary to estimate the propagation channel responses of all receiving antennas in advance for each transmitting station. To this end, it is necessary to transmit a propagation channel response training signal for each transmitting station, or the receiving station side needs to estimate each propagation channel response without a training signal (estimated blindly). When transmitting a training signal for propagation channel response for each transmitting station, it is necessary to perform time-division transmission to prevent the training signal of each transmitting station from interfering, so the overhead increases by the number of transmitting stations and transmission efficiency deteriorates. There is a problem of doing.

  In addition, when the receiving station cannot grasp all the transmitting stations, a control signal for notifying the timing for transmitting the training signal and the like is separately required, and the transmission efficiency is further deteriorated. This deterioration in transmission efficiency is more conspicuous when the information length is short, that is, when the packet is short. Further, in the case of estimation by blind, a brand algorithm such as CMA (Constant Modulus Algorithm) is required.

  The CMA can be said to be a modification of the MMSE adaptive array for a constant envelope signal. In a radio wave environment where there are multiple waves (delayed waves) such as mobile communication and co-channel interference waves, a desired wave and multiple waves are used.・ It is a technology that was conceived as an adaptive system for suppressing multiple waves, interference waves, etc. in a situation where the power of the interference waves does not change much and little prior knowledge about the direction of arrival is obtained. Reference 3).

  There are three types of modulation methods in wireless communication: amplitude modulation, frequency modulation, and phase modulation. Of these, frequency modulation and phase modulation have the property that the envelope of the signal is constant. When these signals pass through multiple propagation paths and arrive at the reception point as time-delayed radio waves (multiple waves or delayed waves), or when interference waves from separate wave sources are incident, the combined signal is The constant property of the envelope is lost, and a fluctuation component is generated in the envelope.

  The principle of operation of the CMA is to control the weight and suppress the multiple wave / interference wave so that the distortion component of the envelope of the array output is minimized. As described above, CMA belongs to the MMSE adaptive array in terms of minimum error, but does not require a reference signal like MMSE as long as the condition that the desired signal has a constant envelope characteristic is satisfied. .

However, in order for the brand algorithm to operate normally, a certain number of symbols is required, and it is impossible to accurately estimate the channel response by the pruning algorithm with a short bucket such as a control packet. Therefore, it is difficult to apply CMA for short packets.
“Basics of Mobile Communications”, edited by IEICE “Basics of Mobile Communication”, P166-170. Editor "Applied signal processing by array antenna", author Nobuyoshi Kikuma, publisher, Science and Technology Publishing Co., Ltd.

  As described above, when the receiving station is equipped with a plurality of receiving antennas and performs reception diversity, in the case of site reception diversity equipped with receiving antennas at a plurality of points, when a plurality of transmitting stations transmit simultaneously by random access or the like. If MRC or selection diversity is performed using the reception signals of all reception antennas, the number of transmission stations that can be successfully demodulated may be smaller than when MRC or selection diversity is performed using only reception signals of reception antennas at each point. there were. Also, in MMSE that optimizes the demodulation success rate of each transmitting station, transmission efficiency deteriorates when propagation channel response estimation is performed using a training signal for short packets, and propagation channel response estimation accuracy is improved when blind estimation is performed. There was a problem of deterioration.

  The present invention has been made in consideration of such circumstances, and the purpose thereof is to succeed in demodulating all the transmitting stations regardless of the combination of the received signals of the receiving antennas without depending on the length of the packet length. And providing a wireless signal receiving method and a wireless signal receiving method.

  In order to solve the above-described problem, the present invention provides a radio signal receiving apparatus including N (N ≧ 2) radio antennas, and at least K types (N types of radio signals are received from the N radio signals received by the radio antennas. An extraction means for extracting a combination of M (1 ≦ M ≦ N) signals having a value of K ≧ 2) and outputting it as a signal sequence, and for each signal sequence output from the extraction means, M = In the case of 1, single demodulation is performed, and in the case of M ≧ 2, demodulation means for performing M branch reception diversity demodulation, error detection for each signal output from the demodulation means, and no error An apparatus for detecting a radio signal, comprising: error detection means for outputting the determined signal.

According to the present invention, in the above invention, when the extraction unit extracts a combination of M signals from N received signals, all the M combinations are extracted, and _N C _M signal sequences are obtained. It is characterized by outputting.

  The present invention is characterized in that, in the above invention, the extracting means extracts a combination of N signals having all N types of values from 1 to N as the K types.

In the present invention, in the above invention, when the wireless antennas are installed apart from a plurality of points # 1 to #P, the number of wireless antennas at each point is L _i (1 ≦ i ≦ P), The extraction means extracts a combination of M signals that satisfy (min _{1 ≦ i ≦ P} (L _i ) ≦ M ≦ N) and satisfy M = L _i (1 ≦ i ≦ P). Features.

  The present invention is characterized in that, in the above-mentioned invention, further comprises a determination unit that outputs the signal output from the error detection unit by eliminating duplication.

  The present invention is characterized in that, in the above invention, a plurality of the extraction means are arranged and perform extraction processing in parallel, and a plurality of the demodulation means are arranged and perform extraction processing in parallel.

  The present invention is characterized in that, in the above invention, a plurality of the extraction means are arranged and perform extraction processing in a time series, and a plurality of the demodulation means are arranged and perform extraction processing in a time series.

  In order to solve the above-described problem, the present invention provides a radio signal receiving method for receiving radio signals by N (N ≧ 2) radio antennas, from N radio signals received by the radio antennas. An extraction step of extracting a combination of M (1 ≦ M ≦ N) signals having at least K types (K ≧ 2) and outputting them as signal sequences, and for each of the extracted signal sequences, When M = 1, single demodulation is performed. When M ≧ 2, a demodulation step for performing M-branch reception diversity demodulation and error detection are performed for each demodulated signal, and it is determined that there is no error. And an error detection step of outputting the processed signal.

In the present invention, in the above invention, when the extraction step extracts a combination of M signals from N received signals, all the M combinations are extracted, and _N C _M signal sequences are obtained. It is characterized by outputting.

  The present invention is characterized in that, in the above invention, the extraction step extracts combinations of N signals having all N types of values from 1 to N as the K types.

In the present invention, in the above invention, when the wireless antennas are installed apart from a plurality of points # 1 to #P, the number of wireless antennas at each point is L _i (1 ≦ i ≦ P), The extraction step is to extract a combination of M signals that satisfy (min _{1 ≦ i ≦ P} (L _i ) ≦ M ≦ N) and satisfy M = L _i (1 ≦ i ≦ P). Features.

  The present invention is characterized in that, in the above-mentioned invention, the method further includes a determination step of outputting the signal output from the error detection step by eliminating duplication.

  According to the present invention, a combination of M (1 ≦ M ≦ N) signals having at least K types (K ≧ 2) values is extracted from N radio signals received by N radio antennas. Are output as signal sequences, and for each of the output signal sequences, single demodulation is performed when M = 1, and M branch reception diversity demodulation is performed when M ≧ 2, and demodulated. Error detection is performed on each signal, and a signal determined to have no error is output. Therefore, among the received signals of each receiving antenna, MRC and selection diversity using a certain combination can be shared with MRC and selection diversity using another combination, and demodulation succeeds with any MRC or selection diversity. The advantage is that all the transmitting stations can be successfully demodulated. Further, since it does not depend on the length of the transmitted radio signal, there is an advantage that it can be applied to a short bucket to which the blind algorithm, that is, MMSE cannot be applied.

Also, according to the present invention, when extracting a combination of M signals from N received signals, all M combinations are extracted and output as _N C _M signal sequences. Therefore, when there is a limit on the number of branches for receiving diversity demodulation, when multiple transmitting stations transmit at the same time, all the receiving diversity with the optimal combination of receiving antennas for the signals of each transmitting station under this limitation is covered. Therefore, there is an advantage that the signal demodulation success rate of each transmitting station can be maximized.

  Further, according to the present invention, combinations of N signals having all N types of values from 1 to N are extracted as K types. Therefore, there is an advantage that the number of branches can be completely covered and combinations within each branch number can be limited.

Further, according to the present invention, when wireless antennas are installed apart from a plurality of points # 1 to #P, the number of wireless antennas at each point is set to L _i (1 ≦ i ≦ P), and (min ₁ A combination of M signals satisfying the condition of _{≦ i ≦ P} (L _i ) ≦ M ≦ N) and M = L _i (1 ≦ i ≦ P) is extracted. Therefore, only the minimum necessary reception diversity demodulation can be performed from the positional relationship of the receiving antenna, and there is an advantage that the operation circuit scale and the processing time can be greatly reduced.

  In addition, according to the present invention, the signal output from the error detection means is output by eliminating duplication. Therefore, there is an advantage that it is possible to prevent unnecessary redundant bit sequences from being transferred to an upper layer such as a MAC unit.

  In addition, according to the present invention, a plurality of extraction means are arranged to perform extraction processing in parallel, and a plurality of demodulation means are arranged to perform extraction processing in parallel. Therefore, when the processing time is limited due to the control response time of the upper layer, etc., there is an advantage that the processing time can be further reduced.

  In addition, according to the present invention, a plurality of extraction means are arranged to perform extraction processing in time series, and a plurality of demodulation means are arranged to perform extraction processing in time series. Therefore, when the size of the radio signal receiving apparatus is limited due to the installation space or the like, there is an advantage that the arithmetic circuit scale can be reduced more greatly.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

<First Embodiment> Claim 1 FIG. 1 is a block diagram showing a configuration of a radio signal receiving apparatus according to a first embodiment of the present invention. In the figure, a radio signal receiving apparatus 1 includes N receiving antennas 1-1-1 to 1-1-N, N radio receiving units 1-2-1 to 1-2-N, and extracting means 1-3. , Demodulation means 1-4, and error detection means 1-5. The radio receiving units 1-2-1 to 1-2N convert radio signals received from the N receiving antennas 1-1-1 to 1-1-N into baseband signals. The extraction unit 1-3 extracts a combination of M signals from the output signals of the N radio reception units 1-2-1 to 1-2N as a signal sequence. However, M takes K types (K ≧ 2), and each M is expressed as M ₁ , M ₂ ,..., M _K. The extraction unit 1-3 performs extraction on each of M _i , M ₂ ,..., M _K. The demodulating means 1-4 determines each signal sequence of M ₁ , M ₂ ,..., M _K output from the extracting means 1-3 when M _i = 1 (1 ≦ i ≦ K). In the case of M _i ≧ 2 (1 ≦ i ≦ K), M _i (1 ≦ i ≦ K) branch reception diversity demodulation is performed. The error detection means 1-5 performs error detection on each output signal of the demodulation means 1-4, and outputs a signal determined as having no error.

Next, the operation of the first embodiment will be described.
First, radio signals # 1 to #N received by N reception antennas 1-1-1 to 1-1-N are respectively transmitted by N radio reception units 1-2-1 to 1-2N. Then, N baseband signals # 1 to #N are converted by frequency conversion. If the subsequent processing is analog processing, it may be an analog signal, or if it is digital processing, it is converted into a digital signal by analog-digital conversion processing.

Next, the extraction means 1-3 extracts a combination of M _i signals for each of M ₁ , M ₂ ,..., M _K from N baseband signals # 1 to #N. . For example, when M ₁ = 2, for M ₁ , two combinations of baseband signals # 1 to #N, (# 1, # 2), (# 1, # 3),. 1, #N), (# 2, # 3), (# 2, # 4),..., (# N-1, #N) one set of combinations, or a plurality of sets of signal sequences. Extract. Further, for _example, in the case of _M 2 = 3, for _{M 2} are three combinations from the baseband signal # 1~ # N, (# 1 , # 2, # 3), (# 1, # 2, # 4), (# 1, # 2, # 5), ..., (# 1, # 2, #N), (# 1, # 2, # 4), ..., (# N-2, # N- 1 or #N), one set or a plurality of sets of signal sequences are extracted. Therefore, from the extraction means 1-3, for each of M ₁ , M ₂ ,..., M _K , a signal sequence set for the number of combinations of M ₁ signals and a signal for the number of combinations of M ₂ signals. Sequence sets, ..., signal sequence sets for the number of combinations of M _K signals are output.

As a specific realization method, a means for extracting a combination of M ₁ , M ₂ ,..., M _K signals is separately provided for the baseband signals # 1 to #N, and each extraction is performed. A method of performing operations in parallel (corresponding to a sixth embodiment to be described later), baseband signals # 1 to #N are input K times, and combinations of M ₁ , M ₂ ,..., M _K signals for each input Can be extracted in order (corresponding to a seventh embodiment to be described later).

Next, the demodulating unit 1-4 applies M _i = 1 (1 ≦ i) to the signal sequence of combinations of M ₁ , M ₂ ,..., M _K signals extracted from the extracting unit 1-3. In the case of ≦ K), single demodulation is performed, and in the case of M _i ≧ 2 (1 ≦ i ≦ K), M _i (1 ≦ i ≦ K) branch reception diversity demodulation is performed.

Specifically, in the case of single demodulation (M _i = 1 (1 ≦ i ≦ K)), after performing appropriate demodulation processing on each extracted received signal, bit determination is performed. Note that error correction or the like may be performed before bit determination. That is, demodulation pit sequence of a signal number of extracted against M _i is output. When the demodulation method is synchronous detection, it is necessary to estimate the propagation channel response corresponding to the corresponding signal before detection. In this case, the propagation channel response is estimated assuming that the transmitting station is one station. Therefore, even when a plurality of transmitting stations transmit simultaneously, one propagation channel response may be estimated for each signal as the combined propagation channel response of each transmitting station. Therefore, it is not necessary to divide the training signal for each transmitting station as in MMSE, and if one training signal is added, the propagation channel response can be estimated. There is no need to use a blind algorithm.

On the other hand, if the branch receive diversity demodulation _{(M i ≧ 2 (1 ≦} i ≦ K)), for each combination of the extracted signal sequence with respect to M _i, performs M _i branch reception diversity demodulation. For example, in the case of M _i = 3, when the reception diversity is the selection diversity for the three signal sequences of a certain combination extracted, the magnitude of the propagation channel response corresponding to each is compared, and the largest signal Only single demodulate. When the reception diversity is MRC, the signals are combined at the maximum ratio based on the respective propagation channel responses, and then appropriate demodulation processing is performed to perform bit determination. Note that error correction may be performed before bit determination, as in single demodulation. The same processing is performed for the extracted three signal sequences of other combinations. In addition, it is exactly the same, even if M _i is other than 3.

As described above, the demodulating means 1-4 outputs demodulated bit sequences for the number of combinations of input signals. Note that the specific implementation method of the demodulating means 1-4 described above is that M _i branch reception diversity demodulation, M ₂ branch reception diversity demodulation,..., M _K branch reception diversity demodulation (M _i = 1 (1) In the case of ≦ i ≦ K), a means for performing single demodulation) is separately provided, and each reception diversity demodulation is performed in parallel (corresponding to a sixth embodiment described later), or an input signal is input K times. , a method of performing sequentially M _i branch receive diversity demodulation for each input (corresponding to the seventh embodiment to be described later) are considered.

  Next, all these demodulated bit sequences are input to the error detection means 1-5, and errors are detected for each demodulated bit sequence. Only the demodulated bit sequence determined to have no error is regarded as the final demodulated bit sequence (final demodulated bit sequence # 1 to #S) and is output. Specifically, it is handed over to an upper layer such as a MAC (Media Access Control) unit.

  According to the first embodiment described above, the radio signal receiving apparatus can simultaneously perform single demodulation and a plurality of combinations of reception diversity demodulation on the reception signals # 1 to #N of the N reception antennas. Is possible. Therefore, if multiple transmit stations transmit simultaneously and receive diversity demodulation of a combination of received signals from one receive antenna, demodulation of a signal from one transmit station succeeds, and receive diversity demodulation of a combination of receive signals from another receive antenna Then, in the case where the demodulation of the signals of the other transmitting stations is successful, the signals of both transmitting stations can be successfully demodulated. Further, in the first embodiment, unlike the MMSE, a training signal for each transmitting station is unnecessary and a blind algorithm is not necessary, so that it can be applied regardless of the length of the packet length. .

<Second Embodiment> Claim 2 Next, a second embodiment of the present invention will be described.
In the second embodiment, when the extraction means 1-3 according to the first embodiment described above extracts a combination of M ₁ , M ₂ ,..., M _K signals from N received signals, The objective is to extract all M _i (1 ≦ i ≦ K) combinations for each M ₁ , M ₂ ,..., M _K.

FIG. 2 is a block diagram showing the configuration of the extracting means 1-3 according to the second embodiment. 2, the extraction means 1-3, each _{M 1,} M 2, ..., (corresponding to the sixth embodiment described later) for performing an operation in parallel to extract a combination of _{M K} number of signals. The extraction unit 1-3 applies all M ₁ combinations to the N baseband signals # 1 to #N output from the N radio reception units 1-2-1 to 1-2N. _extracted, with _N C _M1 or extraction means 1-3-1 for outputting N _{C M1} sets of signal sequences set to extract the _two all combinations _{M, N} and outputs the N _{C M2} sets of signal sequences set C and _M2 pieces extracting unit 1-3-2, ..., extracts _{M K-number} of all combinations _composed of _N C _MK number extracting unit 1-3-K for outputting the N _{C MK} sets of signal sequences set.

Next, the operation of the second embodiment will be described.
The one NCM extracting unit 1-3-1 outputs each set of signal sequences for all combinations for selecting M1 from the baseband signals # 1 to #N. For example, when M _i = 2, (# 1, # 2), (# 1, # 3), ... (# 1, #N), (# 2, # 3), (# 2, # 4), ..., a signal sequence set of all combinations of (# N-1, #N) is output. The same applies to the _N C _M2 extracting means 1-3-2,..., The _N C _MK extracting means 1-3-3-K.

In the above-described operation, the extraction operations of M ₁ , M ₂ ,..., M _K are performed in parallel, but each extraction operation may be performed in a time division manner. That is, the baseband signals # 1 to #N are input K times, and _N C _M1 extraction means 1-3-1, _N C _M2 extraction means 1-3-2,..., _N C _MK extraction means in order. The 1-3K operation may be performed (corresponding to a seventh embodiment described later). The output signal is a demodulating means 1 for performing M ₁ branch reception diversity demodulation, M ₂ branch reception diversity demodulation,..., M _K branch reception diversity demodulation in exactly the same manner as the radio signal receiving apparatus according to the first embodiment described above. 4 is input.

According to the second embodiment described above, the radio signal receiving apparatus is a single of all combinations for each of M ₁ , M ₂ ,..., M _{K with} respect to the received signals # 1 to #N of N receiving antennas. Demodulation and reception diversity demodulation can be performed simultaneously. Therefore, for example, N reception antennas are provided on the radio signal receiving apparatus side, but due to physical limitations such as calculation processing time and circuit scale, among the combinations of all reception antennas, M ₁ branch reception diversity demodulation, M ₂ branch receive diversity demodulation, ..., only M _K branch reception diversity demodulation equipment, in situations where it operates, it is possible to perform single-demodulating a combination of all receive antennas under this limit, as well as receive diversity demodulation simultaneously . As a result, when there is a limit on the number of branches for reception diversity demodulation with respect to the radio signal receiving apparatus according to the first embodiment described above, when a plurality of transmitting stations transmit at the same time, Since it is possible to cover all reception diversity with the optimal combination of receiving antennas for signals, it is possible to maximize the signal demodulation success rate of each transmitting station.

<Third Embodiment> Invention of Claim 3 Next, a third embodiment of the present invention will be described.
In the third embodiment, in the extraction means 1-3 according to the first embodiment described above, a combination of signals for all N types of one side, two, three,..., N from N received signals. The purpose is to extract a series.

  FIG. 3 is a block diagram showing the configuration of the extracting means 1-3 according to the third embodiment. In FIG. 3, the extracting means 1-3 performs an operation of extracting combinations of 1, 2, 3,..., N signals in parallel (corresponding to a sixth embodiment described later). The extraction unit 1-3 is a combination of signal sequences for the N baseband signals # 1 to #N output from the N radio reception units 1-2-1 to 1-2N. One extraction means 1-3-1 ′ for extracting a set, two extraction means 1-3-2 ′ for extracting two combination signal series sets,..., N combinations of signal series sets are extracted N extraction means 1-3-3-N ′.

Next, the operation of the third embodiment will be described.
The one extracting means 1-3-1 ′ regards one signal series as one set from the baseband signals # 1 to #N, and extracts and outputs one set or a plurality of sets. This is substantially an operation of extracting one or a plurality of baseband signals # 1 to #N and outputting them. The two extraction means 1-3-2 ′ are a combination of two of the baseband signals # 1 to #N, that is, (# 1, # 2), (# 1, # 3),. , #N), (# 2, # 3), (# 2, # 4),..., (# N-1, #N), a combination set or a plurality of sets of signal sequences are extracted. To do. Hereinafter, the three extracting means 1-3-3 ′,..., The N−1 extracting means 1-3-3-N-1 ′ perform the same operation as the two extracting means 1-3-2 ′. The N extracting means 1-3-N ′ outputs all baseband signals # 1 to #N as one set.

  In the above-described operation, the operation of extracting the signal sequence set of the combinations for all N types of one, two, three,..., N from the base expanded signals # 1 to #N is performed in parallel. The extraction operation may be performed in a time division manner. That is, baseband signals # 1 to #N are inputted K times, and one extraction means 1-3-1 ′, two extraction means 1-3-2 ′,. The operation of N ′ may be performed (corresponding to a seventh embodiment described later). The output signal is exactly the same as that of the radio signal receiving apparatus according to the first embodiment described above. One-branch reception diversity demodulating means 1-4-1, 2-branch receiving diversity demodulating means 1-4-2,. Input to receiving diversity demodulating means 1-4-N.

  According to the third embodiment described above, the radio signal receiving apparatus performs one, two, three,..., N total N signals for the received signals # 1 to #N of N receiving antennas. Single demodulation of combinations for types and reception diversity demodulation can be performed simultaneously. Therefore, for example, when the number of reception diversity demodulations that can be operated is limited due to physical limitations such as computation processing time and circuit scale on the radio signal receiving device side, the number of branches is limited in the second embodiment described above. Thus, although it is possible to cover all combinations within each branch number, the third embodiment can cover all branch numbers and limit combinations within each branch number.

  Thus, when multiple transmitting stations transmit simultaneously, it is better to limit the number of branches and limit the combinations within each branch than to limit the number of branches to cover all the combinations within each branch number. In cases where the demodulation success rate of each transmitting station is improved, for example, it is assumed that there is no set of receiving antennas that are considered to have no diversity effect due to a narrow interval between the receiving antennas. In such a case where reception diversity demodulation is performed, an improvement effect is expected as compared with the second embodiment described above.

  Further, for example, by combining the second embodiment and the third embodiment, single demodulation and all combinations of reception diversity demodulation are simultaneously performed on reception signals # 1 to #N of N reception antennas. It can be carried out.

  Here, FIG. 4 is a block diagram showing a configuration of the extraction unit 1-3 when the second embodiment and the third embodiment are combined. The configuration shown in FIG. 4 is basically a combination of FIG. 2 and FIG. 3, and the operations of the extraction means 1-3 of the second embodiment and the third embodiment are operated in parallel. (Corresponding to a sixth embodiment described later). Of course, these operations can also be performed in time series (corresponding to a seventh embodiment described later).

  With this configuration, when the radio signal receiving apparatus includes N receiving antennas, when a plurality of transmitting stations transmit simultaneously, all the receiving diversity with the optimal receiving antenna combination for all the transmitting station signals is achieved. Since it is possible to cover all, it is possible to maximize the demodulation success rate of the signal of each transmitting station.

<Fourth Embodiment> Claim 4 Next, a fourth embodiment will be described.
The purpose of the fourth embodiment is to select a combination of signal sequences to be extracted in consideration of the positional relationship of each receiving antenna in the extracting means 1-3 according to the first embodiment described above. That is, it is an object to select a combination of reception antennas that perform reception diversity demodulation in consideration of the position of the reception antenna.

  FIG. 5 is a block diagram illustrating a configuration of the wireless signal receiving device 2 according to the fourth embodiment. The configuration shown in FIG. 5 considers, as an example, a case where reception antennas are installed at three points (points A, B, and C) that are remote from each other, and a plurality of reception antennas are installed at each point. The fourth embodiment will be described below by taking this case as an example.

5, the radio signal receiving apparatus 2 includes a _{L 1} single receive antenna _{2-1-1-1～2-1-1-L 1} to the point A, _{L 2} pieces of receiving antennas 2-1 to point B and _{-2-1~2-1-2-L 2,} and _{L 3} pieces of receiving antennas _{2-1-3-1～2-1-3-L 3} to the point C, the receiving antenna 2-1-1- For the received signals of 1-2-1-1-L ₁ , 2-1-2-1 to 2-1-2L ₂ , 2-1-3-1 to 2-1-3-L ₃ Radio reception units 2-2-1-1 to 2-2-1-L ₁ having the same functions as the radio reception units 1-2-1 to 1-2-N 2-2-2-1 to 2- _2-2-L 2, and a _{2-2-3-1~2-2-3-L 3.}

In addition, the wireless signal receiving device 2 includes wireless reception units 2-21-1 to 2-2-1-L ₁ , 2-22-1 to 2-2-2-L ₂ , and 2-2. Extraction means 2-3-1 corresponding to only one type of M = L ₁ of the extraction means for each signal from 3-1 to 2-2-3-L ₃ and only one type of M = L ₂ , Extraction means 2-3-3 corresponding to only one type of M = L ₃ , and wireless reception units 2-2-1-1 to 2-2-1-L ₁ 2-22-1 to 2-2-2-L ₂ , equivalent to the extraction means 1-3 for all signals from 2-23-1 to 2-2-3-L ₃ And an extraction means 2-3-4 having a function.

Furthermore, the radio signal receiving device 2, the output signal of the extracting means 2-3-1,2-3-2,2-3-3, _{L 1} branch reception diversity demodulation means for performing _{L 1} branch receive diversity demodulation 2-4-1, _{L 2} branch reception diversity _{L 2} branch reception diversity demodulation means for demodulating 2-4-2, and _{L 3} branch reception diversity demodulation means 2-4-3 performing _{L 3} branch reception diversity demodulation, extracted Demodulating means 2-4-1 to 2-4-4 having functions equivalent to the demodulating means 1-3 for all output signals of the means 2-3-1, 1-2-3-2, 2-3-3. Is provided with an error detection means 2-5 having a function equivalent to that of the error detection means 1-5.

Next, the operation of the fourth embodiment will be described.
Receiving antennas 2-1-1-1 to 2-1-1-L ₁ , 2-2-1 to 2-1-2-L ₂ , 2-1-3-1 to 2-1-3- L ₃ , wireless receivers 2-2-1-1 to 2-2-1-L ₁ , 2-22-1 to 2-2-2-L ₂ , 2-23-1 to 2- 2-3-L ₃ operates in exactly the same manner as the reception antenna 1-1-1 to 1-1-N and the radio reception units 1-2-1 to 1-2-N described above. A total of L ₁ + L ₂ + L ₃ baseband signals of 1-1 to # 1-L ₁ , # 1-1 to # 1-L ₂ and # 1-1 to # 1-L ₃ are output. Extracting means 2-3-1, for the baseband signals # 1-1 to # _{1-L 1} outputs a total signal as a set. Similarly, extraction unit 2-3-2, extracting means 2-3-3, to the baseband signals _{# 1-1~ # 1-L 2,} # 1-1~ # 1-L 3, respectively, All signals are output as one set.

On the other hand, the extraction means 2-3-4 may all baseband signals _{# 1-1~ #} 1-L _1, with respect to _{# 1-1~ # 1-L 2,} # 1-1~ # 1-L 3 The operation is exactly the same as that of the extraction means 1-3 described above. However, M satisfies (min (L ₁ , L ₂ , L ₃ ) <M ≦ N). Specifically, for example, the value of M is M = L ₁ + L ₂ , L ₂ + L ₃ , L ₃ + L ₁ , L ₁ + L ₂ + L _3, and the signal sequence pairs to be extracted are # 1-1 to # 1. -L ₁ and # 1-1 # _{1-L 2} of the set, # 1-1 # _{1-L 2} and # 1-1 # 1 set of _{1-L 3,} # 1-1 # 1 -L ₃ and # 1-1 to # _{1-L 1} of the set, # 1-1~ # _1-L 1 and # 1-1~ # _{1-L 2} and # 1-1~ # _{1-L 3} It is conceivable to make a total of 4 sets. That is, it is conceivable that the reception antennas at the same point always perform reception diversity demodulation using all reception antennas, and only perform reception diversity combining the points.

Next, the signal sequence # 1-1~ # _1-L 1 set output from the extraction unit 2-3-1, _{L 1} branch reception diversity demodulation means 2-4-1 is, _{L 1} branch received perform diversity demodulation for the signal sequence # 1-1 of # _{1-L 2} set output from the extraction means 2-3-2, _{L 2} branch reception diversity demodulation means 2-4-2 is, _{L 2} performs a branch receive diversity demodulation, for the set of signal sequences # 1-1~ # _{1-L 3} output from the extraction means 2-3-3, _{L 3} branch reception diversity demodulation means 2-4-3 may L ₃ branch reception diversity demodulation is performed.

Further, the demodulating means 2-4-4 performs M-branch reception diversity demodulation for each signal sequence set for each M output from the extracting means 2-3-4. For example, if the combination of the output signal sequence set is described _{above, # 1-1~ # L 1 + L} 2 branch reception diversity demodulation for _{1-L 1} and # of 1-1 to _{1-L 2} set, # For the set of 1-1 to 1-L ₂ and # 1-1 to # 1-L ₃ , L ₂ + L ₃ branch reception diversity demodulation, # 1-1 to # 1-L ₃ and # 1-1 ~ # for _{1-L 1} set _L 3 + _{L 1} branch received diversity - cytidine demodulation, # 1-1 # _{1-L 1} and # 1-1 # _{1-L 2} and # 1-1 for # of _{1-L 3 set,} it performs L _{1 +} L 2 + _{L 3} branch reception diversity demodulation.

  Thereafter, as in the first embodiment described above, the error detection means 2-5 performs error detection on the demodulated bit sequence after reception diversity demodulation, and only those that are determined to be error-free are finally demodulated. Output as bit sequences # 1 to #S.

  The above explanation was made in the case where reception antennas are installed at three points (points A, B, and C) that are remote from each other, and each reception point is equipped with a plurality of reception antennas. The operation is the same in other cases equipped with a receiving antenna.

  According to the fourth embodiment described above, the radio signal receiving apparatus performs only reception diversity demodulation using all receiving antennas for the receiving antennas installed at the same point in consideration of the positional relationship of the receiving antennas. In addition, it is possible to further perform reception diversity demodulation with respect to the combination between the reception antennas straddling each point.

  When multiple transmitting stations transmit simultaneously, the receiving antennas within the same point where the distance from each transmitting station is almost the same, even if multiple combinations of receiving diversity are performed, each receiving antenna Since the reception levels from the transmission stations are almost the same, the effect of improving the demodulation success rate of each transmission station is low, and it is considered that only reception diversity using all reception antennas is performed as usual.

  In the fourth embodiment, while the transmission diversity demodulation of combinations other than all receiving antennas is performed in the same point where the improvement rate of the demodulation success rate of each transmitting station is considered to be small, the transmission station It is possible to simultaneously perform “receive diversity demodulation using all receive antennas within the same point” and “receive diversity demodulation of a combination of receive antennas across points”, which are considered to have a high degree of success in demodulation. And Therefore, it is possible to perform only the necessary minimum reception diversity demodulation from the positional relationship of the receiving antenna with respect to the radio signal receiving apparatus according to the first embodiment described above, and greatly reduce the arithmetic circuit scale and processing time. It is possible.

<Fifth Embodiment> Claim 5 Next, a fifth embodiment of the present invention will be described.
The fifth embodiment differs from the first to fourth embodiments described above by discarding duplicated final demodulated pit sequences output by the error detection means 1-5. Only the demodulated bit sequence is the final demodulated bit sequence.

  FIG. 6 is a block diagram showing a partial configuration of the radio signal receiving apparatus according to the fifth embodiment. In the figure, the radio signal receiving apparatus according to the fifth embodiment includes a determination unit 1-6 in the subsequent stage of the error detection unit 1-6 in addition to the configurations of the first to fourth embodiments described above. Yes. The judging means 1-6 first judges whether or not each inputted demodulated bit sequence is the same series, that is, whether or not they are duplicated.

  Specifically, it is possible to determine whether or not each demodulated bit sequence overlaps by comparing all the demodulated pit sequences output from the error detection means 1-5, or only a partial region of the bit sequence. It may be determined whether or not each demodulated bit sequence overlaps. Further, when comparing only a part of the regions, a method of comparing regions and the like in which ID information of transmitting stations that are clearly different in each transmitting station is described is conceivable. As a result, the determination unit 1-6 performs a process of discarding any one of the duplicate demodulated bit sequences and outputting only one of them. As a result, the bit sequences output from the determination unit 1-6 are different demodulated bit sequences # 1 to #T.

  According to the fifth embodiment, it is possible to prevent unnecessary redundant bit sequences from being transferred to an upper layer such as a MAC unit. Note that the determination unit 1-6 may be performed by the MAC unit.

<Sixth Embodiment> Invention of Claim 6 Next, a sixth embodiment of the present invention will be described.
The purpose of the sixth embodiment is to operate the extraction means 1-3 and the demodulation means 1-4 in parallel with respect to the wireless signal receiving apparatuses according to the first to fourth embodiments described above. Yes. The configuration of the radio signal receiving apparatus is as shown in FIGS. According to the sixth embodiment, it is possible to maintain the processing time even if the total number of operations increases. Therefore, it is more effective when the processing time is limited by the control response time of the higher layer.

<Seventh Embodiment> Invention of Claim 7 Next, a seventh embodiment of the present invention will be described.
The purpose of the seventh embodiment is to operate each extracting means 1-3 and each demodulating means 1-4 in a time-sharing manner with respect to the radio signal receiving apparatus according to the first to fourth embodiments described above. Yes.
7A and 7B are conceptual diagrams for explaining the time division operation of the radio signal receiving apparatus according to the seventh embodiment. In FIGS. 4A and 4B, arrows indicate the passage of time, and extraction means 1-3-1 ″ to 1-3-N ″ or demodulation means 1-4-1 to 1-4-4. It shows that the operations of N are executed in order. According to the seventh embodiment, the circuit scale can be maintained even if the total number of operations increases. Therefore, it is more effective when the size of the radio signal receiving apparatus is limited due to the installation space or the like.

It is a block diagram which shows the structure of the radio | wireless signal receiver by the 1st Embodiment of this invention. It is a block diagram which shows the structure of the extraction means 1-3 by the 2nd embodiment. It is a block diagram which shows the structure of the extraction means 1-3 by the 3rd Embodiment. It is a block diagram which shows the structure of the extraction means 1-3 at the time of combining 2nd Embodiment and 3rd Embodiment. It is a block diagram which shows the structure of the radio signal receiver 2 of the 4th embodiment. It is a block diagram which shows the structure of a part of radio | wireless signal receiver by 5th Embodiment. It is a conceptual diagram for demonstrating the time division operation | movement of the radio | wireless signal receiver by this 7th Embodiment. It is a block diagram which shows the general | schematic structure of the radio signal receiving wave apparatus (reception diversity is performed using all the receiving antennas) by a prior art.

Explanation of symbols

1 radio signal receiving apparatus 1-1-1-1-1-N receive antennas 1-2-1~1-2-N radio receiving sections 1-3 extracting unit 1-4 demodulation means 1-4-1: _{M 1} Branch reception diversity demodulation means 1-4-2: M _2- branch reception diversity demodulation means 1-4-K: M _K branch reception diversity demodulation means 1-5 Error detection means 1-3-1 _N C _M1 piece extraction means 1- 3-2 _N C _M2 Extraction Unit 1-3-K _N C _MK Extraction Unit 1-4-1 M _1- branch Reception Diversity Demodulation Unit 1-4-2 M _2- Branch Reception Diversity Demodulation Unit 1-4-K M _K branch reception diversity demodulation means 1-3-1 ′ one extraction means 1-3-2 ′ two extraction means 1-3-N ′ N extraction means 1-4-1 one branch reception diversity demodulation means 1-4 -2 2-branch receiver Diversity demodulating means 1-4-N N-branch receiving diversity demodulating means 1-3-1 ″ one extracting means 1-3-2 ″ two extracting means 1-3-3-N ″ N extracting means 2 Radio signal Receiving device 2-1-1-1 to 2-1-1-L ₁ , 2-2-1 to 2-1-2-L ₂ , 2-1-3-1 to 2-1-3- L ₃ receiving antenna 2-21-1 to 2-2-1-L ₁ , 2-22-1 to 2-2-2-L ₂ , 2-23-1 to 2-2 3-L ₃ radio reception unit 2-3-1 to 2-3-4 extraction means 2-4-1 L _1- branch reception diversity demodulation means 2-4-2 L _2- branch reception diversity demodulation means 2-4-3 L _3- branch receive diversity demodulator 2-4-4 demodulator 2-4-4-1 M _1- branch receive diversity demodulator 2-4-2-2 M _2- branch receiver Diversity demodulation means 2-5 Error detection means 1-6 Judgment means

Claims (12)

In a radio signal receiving apparatus including N (N ≧ 2) radio antennas,
Extraction means for extracting a combination of M (1 ≦ M ≦ N) signals having at least K types (K ≧ 2) from N radio signals received by the wireless antenna and outputting the combination as a signal sequence When,
Demodulating means for performing single demodulation when M = 1 for each signal series output from the extracting means, and performing M branch reception diversity demodulation when M ≧ 2,
A radio signal receiving apparatus comprising: error detection means for performing error detection on each signal output from the demodulation means and outputting a signal determined to have no error. The extraction means, when extracting a combination of M signals from N received signals, extracts all M combinations and outputs them as _N C _M signal sequences. The radio signal receiving device according to 1.   2. The radio signal receiving apparatus according to claim 1, wherein the extracting means extracts combinations of N signals having all N types of values from 1 to N as the K types. When the wireless antennas are installed apart from each other at a plurality of points # 1 to #P, the number of wireless antennas at each point is L _i (1 ≦ i ≦ P),
The extraction means extracts a combination of M signals that satisfy (min _{1 ≦ i ≦ P} (L _i ) ≦ M ≦ N) and satisfy M = L _i (1 ≦ i ≦ P). The radio signal receiving apparatus according to claim 1.   5. The radio signal receiving apparatus according to claim 1, further comprising a determination unit that outputs a signal output from the error detection unit by eliminating duplication. A plurality of the extraction means are arranged and perform extraction processing in parallel,
5. The radio signal receiving apparatus according to claim 1, wherein a plurality of demodulation means are arranged and perform extraction processing in parallel. A plurality of the extraction means are arranged and perform extraction processing in time series,
5. The radio signal receiving apparatus according to claim 1, wherein a plurality of demodulation means are arranged and perform extraction processing in time series. In a radio signal receiving method for receiving radio signals with N (N ≧ 2) radio antennas,
An extraction step of extracting a combination of M (1 ≦ M ≦ N) signals having at least K types (K ≧ 2) from N radio signals received by the wireless antenna and outputting the combination as a signal sequence When,
For each of the extracted signal sequences, a demodulation step of performing single demodulation when M = 1, and performing M branch reception diversity demodulation when M ≧ 2,
An error detection step of performing error detection on each demodulated signal and outputting a signal determined to be error-free. The extraction step, when extracting a combination of M signals from N received signals, extracts all M combinations and outputs them as _N C _M signal sequences. 9. A radio signal receiving method according to 8.   9. The radio signal receiving method according to claim 8, wherein the extracting step extracts a combination of N signals having all N types of values from 1 to N as the K types. When the wireless antennas are installed apart from each other at a plurality of points # 1 to #P, the number of wireless antennas at each point is L _i (1 ≦ i ≦ P),
The extraction step extracts a combination of M signals that satisfy (min _{1 ≦ i ≦ P} (L _i ) ≦ M ≦ N) and satisfy M = L _i (1 ≦ i ≦ P). The radio signal receiving method according to claim 8.   12. The radio signal receiving method according to claim 8, further comprising a determination step of outputting the signal output from the error detection step by eliminating duplication.

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