JP4170953B2 - Radio apparatus and receiving circuit - Google Patents

Description

  The present invention relates to control of a variable gain amplifier of a receiving apparatus that receives a radio signal subjected to space division multiplexing.

  Currently, Multiple-Input Multiple-Output (MIMO) method, which receives signals transmitted from multiple transmit antennas using multiple receive antennas, is attracting attention as a method that can effectively use radio frequency resources. Multiplex (Space Division Multiplex: SDM) transmission has attracted attention. SDM transmission is a method in which a plurality of antennas are prepared in a transmitter and signals are transmitted simultaneously from the plurality of antennas. For this reason, the amount of information that can be transmitted per unit frequency can be increased as compared with the case of transmission with one antenna (see, for example, Non-Patent Document 1).

In this SDM transmission system, before receiving data transmitted from a plurality of antennas, it is necessary for the receiver to estimate the propagation path characteristics from each transmission antenna to the reception antenna. There was a high demand for technology development with high precision.
Jan Boer and two others “Backwards compatibility”, [online], September 2003, IEEE LMSC (publisher), [searched September 15, 2003], Internet <URL: ftp: // ieee: wireless @ ftp.802wirelessworld.com/11/03/11-03-0714-00-000n-backwards-compatibility.ppt>

  In the SDM transmission system, it is necessary to estimate the propagation path characteristics from each transmission antenna to the reception antenna in the receiver before receiving data transmitted from a plurality of antennas. There was a high demand for technology development with high precision. Further, there has been a high demand for digital processing of SDM signals with high accuracy using the estimated propagation path characteristics.

  The present invention has been made to meet the above-mentioned demands, and can reduce the quantization error of the propagation path estimation signal to obtain high estimation accuracy of the propagation path characteristics, enabling high-precision digital processing. An object is to provide a wireless device.

  In order to achieve the above object, the present invention downconverts a radio signal in a radio apparatus that receives radio signals in which the first information, the second information, and the third information are transmitted at different times, respectively. Frequency conversion means, amplification means for amplifying the signal output from the frequency conversion means, A / D conversion means for A / D conversion of the signal output from the amplification means, and signal output from the A / D conversion means Among these, based on a signal corresponding to the first information, a multiplex number detecting means for detecting the spatial multiplex number of the second information and the spatial multiplex number of the third information, respectively, and a second number detected by the multiplex number detection means A gain determining means for determining a first gain based on the spatial multiplexing number of the information and a second gain based on the spatial multiplexing number of the third information detected by the multiplexing number detecting means; Signal output by the means The signal corresponding to the second information is controlled so that the amplifying means performs with the first gain, and the signal corresponding to the third information among the signals output from the frequency converting means is controlled. And a control means for controlling the amplifying means to perform at the second gain.

  According to the present invention, in the receiving circuit for receiving the radio signal in which the first information, the second information, and the third information are transmitted at different times, the frequency converting means for down-converting the radio signal, and the frequency conversion Amplifying means for amplifying a signal output from the means, A / D converting means for A / D converting the signal output from the amplifying means, and a signal output from the A / D converting means, corresponding to first information Multiplex number detecting means for detecting the spatial multiplex number of the second information and the spatial multiplex number of the third information based on the signal to be transmitted, and based on the spatial multiplex number of the second information detected by the multiplex number detection means. The first gain is determined, and the gain determining means for determining the second gain based on the spatial multiplexing number of the third information detected by the multiplexing number detecting means, and the first of the signals output from the frequency converting means To the information of 2 For the signal to be transmitted, the amplifying means is controlled to perform at the first gain, and for the signal corresponding to the third information among the signals output from the frequency converting means, the amplifying means And a control means for performing control with gain.

  As described above, according to the present invention, the spatial multiplexing number of the second information and the spatial multiplexing of the third information are based on the signal corresponding to the first information among the signals output from the A / D conversion means. Each number is detected, and a gain corresponding to the detected spatial multiplexing number is determined. Using this gain, each signal of the second information and the third information is amplified and received.

  Therefore, according to the present invention, since the second information and the third information can be amplified with a gain corresponding to each spatial multiplexing number, for example, the spatial multiplexing number of the second information is larger than that of the third information. Even when the dynamic range of the second information is smaller than that of the third information, the second information can be sufficiently amplified compared to the quantization range of the A / D conversion means. It is possible to provide a wireless device and a receiving circuit capable of reducing information quantization errors.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
For the purpose of facilitating propagation path estimation on the reception side or improving propagation path estimation accuracy, the transmission side, for example, transmits propagation path estimation signals one by one from each antenna at different times (1 spatial multiplexing number). It is conceivable to use a frame format for transmission, or use a frame format for transmitting a channel estimation signal in a time division manner with a smaller number of spatial multiplexing than the transmission of data signals.

  In general, as the spatial multiplexing number decreases, the dynamic range of the signal on the receiving side tends to be small. Therefore, when the frame format as described above is used, the dynamic range of the channel estimation signal is the data It is considered to be smaller than the signal.

  On the other hand, when performing demodulation processing by digital signal processing on the receiving side, first, it is necessary to convert the received analog signal into a digital signal by an analog / digital (A / D) converter. Therefore, before inputting the received analog signal to the A / D converter, power adjustment control (AGC) is performed so that the signal level falls within the quantization range of the A / D converter.

  In this AGC control method, the transmission side inserts and transmits a signal for calculating the power adjustment gain at the beginning of the frame, and the receiver calculates the gain based on the received power of the gain calculation signal. A method is conceivable in which the gain obtained is set in a variable gain amplifier to control the level of the analog signal. In this method, since the gain is calculated using only the reception power of the gain calculation signal as a reference, the same amplification gain is used for the propagation path estimation signal and the data signal.

  However, when the frame format described above is used, the dynamic range of the propagation path estimation signal is considered to be smaller than that of the data signal. For this reason, in the above-described method in which a common amplification factor is applied to the propagation path estimation signal and the data signal, the propagation path estimation signal cannot be amplified sufficiently wider than the A / D quantization range. It is conceivable that the error in quantizing the signal for use is large, and as a result, the channel estimation accuracy deteriorates.

  FIG. 1 shows the configuration of a wireless communication system to which a wireless receiver 105 according to an embodiment of the present invention is applied. This wireless communication system includes a wireless receiver 105 and wireless transmitters 101 to 104 that transmit wireless signals thereto. Each of the wireless transmitters 101 to 104 includes a plurality of transmission antennas and a wireless transmission unit that transmits a wireless signal through them. In the following description, it is assumed that four transmission antennas are provided.

  The wireless receiver 105 includes a pair of receiving antennas and a wireless receiving unit. The wireless receiver 105 communicates with any one of the wireless transmitters 101 to 104 for a certain period of time. Note that the wireless receiver 105 may include a plurality of antennas and a wireless reception unit.

  FIG. 2 shows a configuration of the wireless transmitter 101 shown in FIG. The same applies to the wireless transmitters 102 to 104. The wireless transmitter 101 includes an information bit string generation unit 201, a serial / parallel conversion unit 202, a transmission frame format determination unit 203, digital modulation units 204 to 207, a memory 208, upconverters 209 to 212, and transmission antennas 213 to 216.

  The information bit string generation unit 201 generates an information bit string to be transmitted to the wireless receiver 105, and outputs the generated information bit string to the serial / parallel conversion unit 202. The serial / parallel conversion unit 202 divides the information bit sequence input from the information bit sequence generation unit 201 into parallel signals according to the frame format determined by the transmission frame format determination unit 203 from a plurality of frame format candidates, Distribution to the digital modulation units 204 to 207 is performed. A specific example of the frame format will be described later.

  The digital modulation units 204 to 207 perform digital modulation on the parallel signal input from the serial / parallel conversion unit 202. The memory 208 stores a plurality of preamble signal data, and outputs the preamble signal data corresponding to the frame format determined by the transmission frame format determination unit 203 to the up-converters 209 to 212.

  Up-converters 209 to 212 add a preamble signal to the parallel signals digitally modulated by corresponding digital modulation sections 204 to 207, and then up-convert them to RF band signals. The RF signals obtained by this up-conversion are transmitted from the transmission antennas 213 to 216 toward the radio receiver 105, respectively.

  3 and 4 show transmission frame formats of radio signals transmitted from the radio transmitters 101 to 104. The wireless transmitters 101 to 104 are assumed to transmit signals by selectively using the transmission frame format shown in FIGS. 3 and 4. The transmission frame format shown in FIG. 3 and the transmission frame format shown in FIG. 4 are different in the number of spatial multiplexing. 3 and 4, the transmission antennas 213 to 216 correspond to any of Tx1, Tx2, Tx3, and Tx4.

  The transmission frame format of FIG. 3 and FIG. 4 is composed of a short preamble (SP) signal part, a long preamble (LP) signal part, and a data signal part. The wireless transmitters 101 to 104 begin with a plurality of consecutive SP signals. Then, the LP signal is transmitted, and finally the data signal is transmitted.

The SP signal is a signal used for gain calculation of a variable gain amplifier 503 (described later) mounted on the reception side, that is, the wireless receiver 105, and is transmitted from one antenna Tx1. However, SP signals shown in FIG. 3 has a waveform S _SP1, SP signal shown in FIG. 4 has a waveform S _SP2, waveform S _SP1 and the waveform S _SP2 has a different waveform. Therefore, the spatial multiplexing number of the LP signal part and the spatial multiplexing number of the data signal part can be determined from the waveforms S _SP1 and S _SP2 .

The LP signal is a signal for estimating propagation path characteristics, and is transmitted with a spatial multiplexing number of 1. Here, when the frame format shown in FIG. 3 is used, the LP signal is transmitted using only the same antenna Tx1 as the antenna that transmitted the SP signal. On the other hand, when the frame format shown in FIG. LP signals are transmitted in time division using Tx1 to Tx4 sequentially. Note that the LP signal shown in FIG. 3 and the LP signal shown in FIG. 4 have the same waveform S _LP .
In this way, the SP signal and the LP signal are transmitted. Here, when the frame format shown in FIG. 3 is used, the data signal S _Dn (n = 0, 1, 2,...) Is transmitted using only the spatial multiplexing number m = 1, that is, the antenna Tx1. When the frame format shown in FIG. 4 is used, the data signal S _Dn (n = 0, 1, 2...) Is transmitted using the spatial multiplexing number m = 4, that is, the antennas Tx1 to Tx4.

  FIG. 5 shows the configuration of the wireless receiver 105 according to the present invention. As shown in this figure, the radio receiver 105 includes a receiving antenna 501, a down converter 502, a variable gain amplifier 503, an A / D converter 504, a received power measuring unit 505, a gain control unit 506, and a digital signal processing unit 507. Prepare.

  First, when the SP signal is received from space by the receiving antenna 501, the received SP signal is converted from an RF signal to a baseband signal by the down converter 502 and then input to the variable gain amplifier 503. The variable gain amplifier 503 amplifies the baseband signal with a preset initial gain and outputs it to the A / D converter 504.

  The A / D converter 504 converts the baseband signal input from the variable gain amplifier 503 into a digital signal. The digital signal obtained by the A / D converter 504 is output to the received power measuring unit 505, the gain control unit 506, and the digital signal processing unit 507.

  The received power measuring unit 505 measures the received power value from the digital signal based on the SP signal. This measurement result is notified to the gain control unit 506. When the notified measurement result is different from the predetermined target power value, the gain control unit 506 calculates the gain to be set in the variable gain amplifier 503 by performing recalculation of the gain, and obtains the gain. Reset to.

  When the gain is reset in the variable gain amplifier 503 in this way, the received power measurement unit 505 again performs power measurement from the output of the A / D converter 504, that is, the digital signal based on the SP signal. Such a gain setting operation is repeatedly executed using the SP signal unit shown in FIGS. 3 and 4 until the measured power value by the received power measuring unit 505 becomes equal to the target value.

Eventually, when the measured power value becomes equal to the target power value, the gain control unit 506 detects the spatial multiplexing number m of the LP signal and the data signal based on the digital signal based on the SP signal. Receiving periods _TLPx and _TDATx (x = 0 or 1) are detected.

Then, the gain control unit 506 determines the gain G _LP of the variable gain amplifier 503 used in the LP signal reception period T _LPx and the data signal reception period T _DATx according to the spatial multiplexing number m of each of the LP signal and the data signal. The gain G _DAT used in is obtained. The gains G _LP and G _DAT obtained here are large when the spatial multiplexing number m is small, that is, when m = 1 in this example, whereas when the spatial multiplexing number m is large, that is, in this example, When m = 4, a small value is obtained.

When the reception of the SP signal is finished, the wireless receiver 105 receives the LP signal and the data signal in order through the reception antenna 501. At this time, the gain control unit 506 sets the gain G _LP in the variable gain amplifier 503 during the period T _LPx during which the LP signal is received, while the gain G _LP during the period T _DATx during which the data signal is received. _DAT is set in the variable gain amplifier 503.

  Thereafter, the variable gain amplifier 503 amplifies the LP signal and the data signal according to the gain set by the gain control unit 506. The amplified LP signal and data signal are converted into digital signals by the A / D converter 504 and then input to the digital signal processing unit 507.

  The digital signal processing unit 507 estimates a propagation path characteristic using a digital signal based on the LP signal, and estimates a transmission signal sequence from the digital signal based on the data signal using the estimated propagation path characteristic information. Description of the propagation path estimation method and the transmission signal sequence estimation method of the digital signal processing unit 507 is omitted.

  FIG. 6 shows a configuration example of the gain control unit 506 shown in FIG. The gain control unit 506 shown in this figure includes matched filters 601, 602, a peak detection unit 603, a frame format determination unit 604, a reception timing detection unit 605, a switch 606, a target selection unit 607, and a gain calculation unit 608.

The matched filter 601 is a digital filter having an impulse response matched with the SP signal shown in FIG. 3, that is, the SP signal having the waveform S _SP1 . On the other hand, the matched filter 602 is a digital filter having an impulse response matched with the SP signal shown in FIG. 4, that is, the SP signal having the waveform _SSP2 . In the matched filters 601, 602, when an SP signal having a matching waveform is input, a high value peak appears in accordance with the input timing of the SP signal.

The digital signal of the SP signal obtained by the A / D converter 504 is input to the matched filters 601 and 602, respectively. When the SP signal is an SP signal having the waveform S _SP1 shown in FIG. 3, the output waveforms of the matched filters 601 and 602 are as shown in FIGS. 7A and 7B, respectively. That is, a periodic peak appears in the output waveform of the matched filter 601 as shown in FIG. 7A, while a peak appears in the output waveform of the matched filter 602 as shown in FIG. 7B. Does not appear.

If the SP signal is an SP signal having the waveform S _SP2 shown in FIG. 4, the output waveforms of the matched filters 601 and 602 are as shown in FIGS. 8A and 8B, respectively. That is, a peak does not appear in the output waveform of the matched filter 601 as shown in FIG. 8A, while a periodic peak is shown in the output waveform of the matched filter 602 as shown in FIG. Appears.

  The output of the matched filters 601 and 602 is given to the peak detection unit 603. Then, the peak detection unit 603 monitors the output to detect the peak, and when a peak is detected from the output of the matched filter 601, the identifier “0” is output to the frame format determination unit 604, while the matched filter 602 When a peak is detected from the output of, the identifier “1” is output to the frame format determination unit 604.

Also, the peak detection unit 603 detects the time t _end when the peak appears last, and notifies the reception timing detection unit 605 of this. The identifier is not limited to the combination of “0” and “1”, and other identifiers can be used.

The frame format determination unit 604 stores information on the identifier and the frame format associated with the identifier in advance. For example, the frame format determination unit 604 stores the following in advance as the information. However where, following _{T LP0, T DAT0, T LP1} , T DAT1 , respectively Figure 3 correspond to those described in FIG.

{Identifier: 0, LP signal space multiplexing number: 1, LP signal length: T _LP1 , Data signal space multiplexing number: 4, Data signal length: T _DAT0 },
{Identifier: 1, LP signal space multiplexing number: 1, LP signal length: T _LP2 , Data signal space multiplexing number: 1, Data signal length: T _DAT1 }.

  The frame format determination unit 604 detects the LP signal spatial multiplexing number, the LP signal length, the data signal spatial multiplexing number, and the data signal length corresponding to the identifier input from the peak detection unit 603, and among these, the LP signal The spatial multiplexing number and the data signal spatial multiplexing number are output to the switch 606, and the LP signal length and the data signal length are output to the reception timing detection unit 605.

The reception timing detection unit 605 receives the LP signal reception start time t _start based on the peak end time t _end notified from the peak detection unit 603 and the LP signal length and data signal input from the frame format determination unit 604. _-LP , the reception start time t _start-DAT of the data signal and the reception end time t _end-DAT of the data signal are obtained.

Here, assuming that the output delay time τ in the matched filters 601 and 602 and the symbol length T _{SP of the} SP signal (common to S _SP1 and S _SP2 ) are known by the reception timing detection unit 605, t _start-LP , t _{start -DAT} and _{tend -DAT} are obtained by the following calculations. In the following expression, “x” corresponds to the value of the identifier.

t _start-LP = t _end + τ + T _SP
t _start-DAT = t _end + τ + T _SP + T _LPx
t _end-DAT = t _end + τ + T _SP + T _LPx + T _DATx
The reception timing detection unit 605 outputs the reception identification number “1” to the switch 606 at the time T _LPx when the LP signal is received based on the result of such calculation, and the data signal is received. The reception identification number “2” is output to the switch 606 at the _remaining time T _DATx , and the reception identification number “0” is output to the switch 606 at other times.

Of the spatial multiplexing numbers input from the frame format determination unit 604, the switch 606 receives the reception identification number “1” from the reception timing detection unit 605, that is, the time T _LPx during which the LP signal is received. When the spatial multiplexing number of the LP signal is output to the target selection unit 607 and the reception identification number “2” is input from the reception timing detection unit 605, that is, at the time T _LPx during which the data signal is received, the space of the data signal The multiplexing number is output to the target selection unit 607.

  The target selection unit 607 stores in advance an initial target value and a plurality of target values corresponding to the spatial multiplexing number. These target values represent target average power values of signals at the time of output of the variable gain amplifier 503, and are set such that the target value increases as the number of spatial multiplexing decreases.

  Then, when the information indicating the spatial multiplexing number is input from the switch 606, the target selection unit 607 selects a target value corresponding to the input spatial multiplexing number information and outputs the target value to the gain calculation unit 608. On the other hand, when the information indicating the spatial multiplexing number is not input from the switch 606, the initial target value is selected and output to the gain calculation unit 608.

The gain calculation unit 608 obtains a gain to be set in the variable gain amplifier 503 based on the reception power value of the SP signal input from the reception power measurement unit 505 and the target value input from the target selection unit 607. Here, it is assumed that the received power value of the SP signal is P _SP [dB] and the target value is P _TARGET [dB]. At this time, the gains G _LP and G _DAT to be set in the variable gain amplifier 503 are obtained by P _TARGET -P _SP [dB]. The gain calculation unit 608 sets the gains G _LP and G _DAT thus obtained in the variable gain amplifier 503.

As described above, in the radio receiver 105 having the above-described configuration, the gain control unit 506 detects the spatial multiplexing number m of the LP signal and the data signal based on the SP signal, and also receives the LP signal reception period T _LPx and the data. The signal reception period _TDATx is detected. The gain control unit 506 controls the variable gain amplifier 503 so as to amplify the LP signal received in the reception period T _LPx with a gain G _LP corresponding to the spatial multiplexing number, and the data received in the reception period T _DATx. The variable gain amplifier 503 is controlled so as to amplify the signal with a gain G _DAT corresponding to the number of spatial multiplexing.

  Therefore, according to the radio receiver 105 configured as described above, since the LP signal and the data signal are amplified with a gain corresponding to each spatial multiplexing number, for example, the spatial multiplexing number of the LP signal used for propagation path estimation is converted into the data signal. Even when the dynamic range of the LP signal is smaller than that of the data signal, the LP signal can be sufficiently amplified compared with the quantization range of the A / D converter 504. And the propagation path can be estimated with high accuracy.

  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. For example, the gain controller 506 shown in FIG. 6 can be configured as shown in FIG. Hereinafter, the gain control unit 506 shown in FIG. 9 will be described.

  The gain control unit 506 shown in this figure includes matched filters 901 and 902, a peak detection unit 903, a frame format determination unit 904, a target selection unit 905, a reception timing detection unit 906, a gain calculation unit 907, and a switch 908.

The matched filter 901 is a digital filter having an impulse response matched with the SP signal shown in FIG. 3, that is, the SP signal having the waveform S _SP1 . On the other hand, the matched filter 902 is a digital filter having an impulse response matched with the SP signal shown in FIG. 4, that is, the SP signal having the waveform _SSP2 . Then, when SP signals having matching waveforms are input to the matched filters 901 and 902, a high value peak appears in accordance with the input timing of the SP signal.

The digital signal of the SP signal obtained by the A / D converter 504 is input to the matched filters 901 and 902, respectively. When the SP signal is an SP signal having the waveform S _SP1 shown in FIG. 3, the output waveforms of the matched filters 901 and 902 are as shown in FIGS. 7A and 7B, respectively. That is, a periodic peak appears in the output waveform of the matched filter 901 as shown in FIG. 7A, whereas a peak appears in the output waveform of the matched filter 902 as shown in FIG. 7B. Does not appear.

When the SP signal is an SP signal having the waveform S _SP2 shown in FIG. 4, the output waveforms of the matched filters 901 and 902 are as shown in FIGS. 8A and 8B, respectively. That is, a peak does not appear in the output waveform of the matched filter 901 as shown in FIG. 8A, whereas a periodic peak is shown in the output waveform of the matched filter 902 as shown in FIG. 8B. Appears.

  The outputs of the matched filters 901 and 902 are given to the peak detector 903. The peak detection unit 903 detects a peak from the output, and when a peak is detected from the output of the matched filter 901, outputs an identifier “0” to the frame format determination unit 904. When a peak is detected, the identifier “1” is output to the frame format determination unit 904.

Also, the peak detection unit 903 detects the time t _end when the peak appears last, and notifies the reception timing detection unit 906 of this. The identifier is not limited to the combination of “0” and “1”, and other identifiers can be used.

The frame format determination unit 904 stores information on the identifier and the frame format associated with the identifier in advance. For example, the frame format determination unit 904 stores the following in advance as the information. However where, following _{T LP0, T DAT0, T LP1} , T DAT1 , respectively Figure 3 correspond to those described in FIG.

{Identifier: 0, LP signal space multiplexing number: 1, LP signal length: T _LP1 , Data signal space multiplexing number: 4, Data signal length: T _DAT0 },
{Identifier: 1, LP signal space multiplexing number: 1, LP signal length: T _LP2 , Data signal space multiplexing number: 1, Data signal length: T _DAT1 }.

  The frame format determination unit 904 detects the LP signal spatial multiplexing number, the LP signal length, the data signal spatial multiplexing number, and the data signal length according to the identifier input from the peak detection unit 903, and among these, the LP signal The spatial multiplexing number and the data signal spatial multiplexing number are output to the target selection unit 905, and the LP signal length and the data signal length are output to the reception timing detection unit 906.

  The target selection unit 905 stores in advance an initial target value and a plurality of target values corresponding to the spatial multiplexing number. These target values represent target average power values of signals at the time of output of the variable gain amplifier 503, and are set such that the target value increases as the number of spatial multiplexing decreases.

  Then, the target selection unit 905 determines each target value of the LP signal and the data signal based on the LP signal spatial multiplexing number and the data signal spatial multiplexing number input from the frame format determination unit 904. Then, the target selection unit 905 outputs these determined target values to the gain calculation unit 907.

The gain calculation unit 907 is a variable gain amplifier at the time of LP signal reception and data signal reception based on the reception power value of the SP signal input from the reception power measurement unit 505 and the target value input from the target selection unit 905. Gains G _LP and G _DAT to be set to 503 are obtained and output to the switch 908. Here, it is assumed that the received power value of the SP signal is P _SP [dB] and the target value is P _TARGET [dB]. At this time, the gains G _LP and G _DAT to be set in the variable gain amplifier 503 are obtained by P _TARGET -P _SP [dB], respectively.

The reception timing detection unit 906 receives the LP signal reception start time t _start based on the peak end time t _end notified from the peak detection unit 903 and the LP signal length and data signal input from the frame format determination unit 904. _-LP , data signal reception start time t _start-DAT and data signal reception end time t _end-DAT are obtained.

Assuming that the output delay time τ in the matched filters 901 and 902 and the symbol length T _{SP of the} SP signal (common to S _SP1 and S _SP2 ) are known by the reception timing detection unit 906, t _start-LP , t _{start -DAT} and _{tend -DAT} are obtained by the following calculations. In the following expression, “x” corresponds to the value of the identifier.

t _start-LP = t _end + τ + T _SP
t _start-DAT = t _end + τ + T _SP + T _LPx
t _end-DAT = t _end + τ + T _SP + T _LPx + T _DATx
The reception timing detection unit 906 outputs the reception identification number “1” to the switch 908 at the time T _LPx when the LP signal is received based on the result of such calculation, and the data signal is received. The reception identification number “2” is output to the switch 908 at the time T _DATx that is _present , and the reception identification number “0” is output to the switch 908 at other times.

Of the gains G _LP and G _DAT input from the gain calculation unit 907, the switch 908 receives the reception identification number “1” from the reception timing detection unit 906, that is, the time T _LPx during which the LP signal is received. the gain G _LP set to the variable gain amplifier 503, if the received identification number "2" is input from the reception timing detection unit 906, i.e. the gain in time T _LPx receiving data signals G _DAT Is set in the variable gain amplifier 503.
The gain control unit 506 has the same effect as the gain control unit 506 shown in FIG.

  Moreover, in the said embodiment, although the transmission frame format of the radio | wireless signal transmitted from the radio | wireless transmitters 101-104 was shown in FIG.3 and FIG.4, it is not limited to this, As shown in FIG. Any transmission frame format may be used. Hereinafter, the case where this transmission frame format is used will be described.

The transmission frame format shown in FIG. 10 includes a short preamble (SP) signal part, a signal signal part (S _SIG-LP and S _SIG ), a long preamble (LP) signal part, and a data signal part. First, the wireless transmitters 101 to 104 continuously transmit a plurality of SP signals. This SP signal is a signal used for gain calculation of the variable gain amplifier on the receiving side (wireless receiver 105).

And the wireless transmitters 101-104 transmit a signal signal part, after transmitting the said SP signal. The signal signal unit includes signal S _SIG-LP for channel estimation to be used for demodulating the signal signal S _SIG, which is composed of a signal signal S _SIG, and LP signal that follows the signal signal S _SIG As the frame format information of the data signal, information on each spatial multiplexing number, signal length, and configuration is included. After transmitting the signal signal portion, the wireless transmitters 101 to 104 transmit the LP signal and the data signal, which are propagation path characteristic estimation signals, to arbitrary spatial multiplexing numbers N _LP , N _DAT (N _LP , N _DAT = 1, 2, 3, 4).

  Next, an operation in radio receiver 105 when using the transmission frame format shown in FIG. 10 will be described. Even when the transmission frame format shown in FIG. 10 is used, the wireless receiver 105 has the same configuration as that shown in FIG. 5 and will be described with reference to FIG.

  A radio signal transmitted from any one of the radio transmitters 101 to 104 is converted into a baseband signal through the receiving antenna 501 and the down converter 502 and output to the variable gain amplifier 503. When the SP signal is received, the gain control unit 506 gains the variable gain amplifier 503 so that the measured power value measured by the received power measurement unit 505 based on the output of the A / D converter 504 is equal to the target value. Make adjustments. Thereafter, the signal signal portion received following the SP signal is amplified by the variable gain amplifier 503, converted to a digital signal by the A / D converter 504, and output to the gain control portion 506.

The gain control unit 506 detects the spatial multiplexing numbers N _LP and N _DAT of the LP signal and the data signal based on the signal signal unit. After that, the gain control unit 506 obtains a gain to be set in the variable gain amplifier 503 when receiving the LP signal and the data signal according to the detected spatial multiplexing numbers N _LP and N _DAT . The gain controller 506 sets the gain when the number of spatial multiplexing is small, and sets the gain when the number of spatial multiplexing is large.

  Then, after receiving the SP signal and the signal signal, the radio receiver 105 continuously receives the LP signal and the data signal. The gain control unit 506 sets the gain of the LP signal to the variable gain amplifier 503 during the time of receiving the LP signal, and the gain of the data signal to the variable gain amplifier 503 during the time of receiving the data signal. Set.

  On the other hand, the variable gain amplifier 503 amplifies the LP signal and the data signal according to the set gain. The LP signal and the data signal thus amplified by the variable gain amplifier 503 are converted into a digital signal by the A / D converter 504 and then output to the digital signal processing unit 507.

  The digital signal processing unit 507 estimates a propagation path characteristic using the LP signal, and estimates a transmission signal sequence from the data signal using the estimated propagation path characteristic information. A description of the propagation path estimation method and the transmission signal sequence estimation method in the digital signal processing unit 507 is omitted.

  Next, FIG. 11 shows a configuration example of the gain control unit 506 when the transmission frame format shown in FIG. 10 is used. The gain control unit 506 includes a matched filter 1101, a peak detection unit 1102, a signal signal reception timing detection unit 1103, a reception timing detection unit 1104, a signal signal propagation path estimation unit 1105, a signal signal demodulation unit 1106, and a frame format information detection unit. 1107, a switch 1108, a target selection unit 1109, and a gain calculation unit 1110.

Matched filter 1101 is a digital filter having an impulse response matched to the SP signal S _SP. For this reason, when the SP signal converted into the digital signal is input to the matched filter 1101, a peak appears periodically in the output of the matched filter 1101 at the timing when the SP signal is input as shown in FIG. It will be.

The peak detector 1102 receives the output of the matched filter 1101 and detects a peak from the output waveform. Then, the peak detection unit 1102 notifies the signal signal reception timing detection unit 1103 and the reception timing detection unit 1104 of the time t _end when the peak appears last.

The signal signal reception timing detection unit 1103 includes a peak end time t _end notified from the peak detection unit 1102, a signal S _SIG-LP of the signal signal unit held in advance, a symbol length T _{SIG-LP of} S _SIG , Based on T _SIG , signal S _SIG-LP reception start time t _start-SIG-LP , signal S _SIG reception start time t _start-SIG and signal S _SIG reception end time t _end-SIG are calculated.

Here, since the output delay time τ in the matched filter 1101 and the symbol length T _{SP of the} SP signal are known by the signal signal reception timing detection unit 1103, the signal signal reception timing detection unit 1103 receives the time t _{start− LP} , t _start-DAT and t _end-DAT are obtained by the following equations, respectively.

t _start-SIG-LP = t _end + τ + T _SP
t _start-SIG = t _end + τ + Tsp + T _SIG-LP
t _end-SIG = t _end + τ + Tsp + T _SIG-LP + T _SIG
Then, the signal signal reception timing detection unit 1103 estimates the received signal identifier “1” for the signal signal propagation path during the time when the signal S _SIG-LP is received at the timing based on the calculation result as described above. Output to unit 1105 and signal signal demodulator 1106, while receiving signal S _SIG is output to received signal identifier “2” to signal signal propagation path estimator 1105 and signal signal demodulator 1106. . At other times, the received signal identifier “0” is output to the signal signal propagation path estimation unit 1105 and the signal signal demodulation unit 1106.

The signal signal propagation path estimation unit 1105 does not operate when the reception identification number input from the signal signal reception timing detection unit 1103 is other than “1”. When the reception identification number input from the signal signal reception timing detection unit 1103 is “1”, that is, when the signal S _SIG-LP is received, the signal S _SIG-LP is extracted from the received signal. The propagation path characteristic used for demodulating the signal signal S _SIG is estimated.

The signal signal demodulator 1106 does not operate when the reception identification number input from the signal signal reception timing detector 1103 is other than “2”. When the reception identification number input from the signal signal reception timing detector 1103 is “2”, that is, when the signal signal S _SIG is received, the signal signal demodulator 1106 receives the signal signal S _SIG from the received signal. The signal signal S _SIG is demodulated using the propagation path characteristic extracted and estimated by the signal signal propagation path estimation unit 1105. The demodulated data demodulated in this way is output to the frame format information detection unit 1107. Description of this demodulation algorithm is omitted.

Based on the demodulated data input from the signal signal demodulating unit 1106, the frame format information detecting unit 1107 receives the LP signal spatial multiplexing number N _LP , the data signal spatial multiplexing number N _DAT , and the LP signal signal length T _LP based on the demodulated data. The signal length T _DAT of the data signal is detected. Then, the detected LP signal spatial multiplexing number N _LP and the data signal spatial multiplexing number N _DAT are output to the switch 1108, while the detected LP signal signal length T _LP and data signal signal length T _DAT are received. The data is output to the timing detection unit 1104.

The reception timing detection unit 1104 receives the LP end time t _end notified from the peak detection unit 1102, the signal length T _{LP of the LP} signal and the signal length T _{DAT of the} data signal input from the frame format information detection unit 1107. A signal reception start time t _start-LP , a data signal reception start time t _start-DAT , and a data signal reception end time t _end-DAT are calculated.

Here, output delay time τ in the matched filter 1101, on the basis of symbols of the SP signal length T _SP, the symbol length T _SIG signal S symbol length _SIG-LP T _SIG-LP and signal signal S _SIG, the reception timing detection unit Since it is known in 1104, the reception timing detection unit 1104 obtains times t _start-LP , t _start-DAT and t _end-DAT by the following equations.

t _start-LP = t _end + τ + T _SP + T _SIG-LP + T _SIG
t _start-DAT = t _end + τ + T _SP + T _SIG-LP + T _SIG + T _LP
t _end-DAT = t _end + τ + T _SP + T _SIG-LP + T _SIG + T _LP + T _DAT
The reception timing detection unit 1104 outputs the reception identification number “1” to the switch 1108 during the time when the LP signal is received at the timing based on the above calculation result, and at the time when the data signal is received. Outputs the reception identification number “2” to the switch 1108. At other times, the reception identification number “0” is output to the switch 1108.

When the reception identification number input from the reception timing detection unit 1104 is “1”, that is, when the LP signal is received, the switch 1108 outputs the LP signal spatial multiplexing number N _LP to the target selection unit 1109, On the other hand, when the reception identification number input from the reception timing detection unit 1104 is “2”, that is, when a data signal is received, the spatial multiplexing number N _DAT of the data signal is output to the target selection unit 1109.

The target selection unit 1109 stores a preset initial target value and a plurality of target values corresponding to the number of spatial multiplexing (N _LP , N _DAT ). These target values represent target average power values of signals at the time of output of the variable gain amplifier 503, and are set such that the target value increases as the number of spatial multiplexing decreases.

  Then, when information indicating the spatial multiplexing number is input from the switch 1108, the target selection unit 1109 selects a target value corresponding to the input spatial multiplexing number information and outputs the target value to the gain calculation unit 1110. On the other hand, when the information indicating the spatial multiplexing number is not input from the switch 1108, the initial target value is selected and output to the gain calculation unit 1110.

The gain calculation unit 1110 obtains a gain to be set in the variable gain amplifier 503 based on the reception power value of the SP signal input from the reception power measurement unit 505 and the target value input from the target selection unit 1109. Here, it is assumed that the received power value of the SP signal is P _SP [dB] and the target value is P _TARGET [dB]. At this time, the gains G _LP and G _DAT to be set in the variable gain amplifier 503 are obtained by P _TARGET-PSP [dB]. The gain calculation unit 608 sets the gains G _LP and G _DAT thus obtained in the variable gain amplifier 503.

As described above, when the transmission frame format shown in FIG. 10 is used, the gain control unit 506 shown in FIG. 11 calculates the spatial multiplexing numbers N _LP and N _DAT of the LP signal and the data signal based on the signal signal. While detecting each, the LP signal reception start time t _start-LP and the data signal reception start time t _start-DAT are detected. The gain control unit 506 controls the variable gain amplifier 503 so as to amplify the LP signal received after the reception start time t _start-LP with a gain G _LP corresponding to the spatial multiplexing number N _LP and start reception. The variable gain amplifier 503 is controlled so that a data signal received after time t _start-DAT is amplified with a gain G _DAT corresponding to the spatial multiplexing number N _DAT .

Therefore, even when the transmission frame format shown in FIG. 10 is used, by using the gain control unit 506 shown in FIG. 11, the LP signal and the data signal are _gained in accordance with the respective spatial multiplexing numbers N _LP and N _DAT. In order to amplify, for example, even when the spatial multiplexing number N _LP of the LP signal used for propagation path estimation is smaller than the spatial multiplexing number N _DAT of the data signal and the dynamic range of the LP signal is smaller than that of the data signal, A Since the LP signal can be sufficiently amplified compared with the quantization range of the / D converter 504, the quantization error of the LP signal can be reduced, and the propagation path can be estimated with high accuracy.

  In the above embodiment, the transmission frame format of the radio signal transmitted from the radio transmitters 101 to 104 is shown in FIGS. 3, 4, and 10. However, the present invention is not limited to this. A transmission frame format as shown in FIG. Hereinafter, the case where this transmission frame format is used will be described.

  The transmission frame format shown in FIG. 13 includes a short preamble (SP) signal portion, a long preamble (LP) signal portion, a first signal (SIG1) signal portion, a second signal (SIG2) signal portion, and an AGC preamble (AGC) signal. Part, a MIMO long preamble (MIMO-LP) part and a MIMO data signal (MIMO-DATA) part.

  Hereinafter, the operation of the wireless receiver 105 when such a transmission frame format is used will be described. A radio signal transmitted from any one of the radio transmitters 101 to 104 is converted into a baseband signal through the receiving antenna 501 and the down converter 502 and output to the variable gain amplifier 503.

  When receiving the SP signal, the gain control unit 506 adjusts the gain of the variable gain amplifier 503 so that the power value measured by the reception power measurement unit 505 based on the output of the A / D converter 504 is equal to the target value. .

Normally, gain adjustment based on one SP signal rarely results in a target value, so that gain adjustment is repeated a plurality of times using a plurality of SP signals. This gain adjustment is the first AGC control, and the target value at this time is T _SISO . Thereafter, the wireless receiver 105 performs channel estimation using the LP signal that is subsequently received. Since propagation path estimation can be realized using a known technique, description thereof is omitted.

  Next, the radio receiver 105 demodulates the SIG1 signal. For details of the SIG1 signal, as shown in FIG. 13, the RATE part from 0 to 3 bits indicates the modulation method of the subsequent radio frame, and the R (reserved bit) part of the fourth bit indicates the subsequent radio frame. Is a bit indicating whether or not a plurality of antennas Tx1 to Tx4 are transmitted.

  In the following description, when the R part is “1”, it is assumed that transmission is performed from a plurality of antennas Tx1 to Tx4 in the transmission frame format as shown in FIG. 13, while when the R part is “0”. Are transmitted only from a single antenna (for example, Tx1) in the transmission frame format as shown in FIG.

  The LENGTH part of the 5th to 16th bits describes the length of the radio frame, the P part of the 17th bit indicates a parity check, and the SIGNAL TAIL part of the 18th to 23rd bits indicates a convolutional encoder. Used to terminate.

  Next, the radio receiver 105 demodulates the SIG2 signal. This SIG2 signal is a field for the SDM signal, and describes the modulation scheme of the subsequent radio frame, the number of multiplexed SDMs, and the like.

  Subsequently, the wireless receiver 105 receives an AGC signal. The AGC signal is a signal used for AGC control for receiving signals transmitted from the multiple antennas Tx1 to Tx4. By using this AGC signal, it is possible to amplify signals transmitted from a plurality of antennas Tx1 to Tx4 to an appropriate level and perform A / D conversion, thereby enabling high-accuracy reception.

Next, FIG. 15 shows a configuration of gain control section 506 corresponding to the transmission frame format. Hereinafter, the operation of the gain control unit 506 shown in this figure will be described.
The signal signal demodulator 1401 demodulates the SP signal and outputs the demodulation result to the frame format information detector 1402.

  On the other hand, since the input signal is an SP signal, the frame format information detection unit 1402 issues a command to the gain calculation unit 1404 to start the first AGC control using the SP signal.

At this time, the frame format information detection unit 1402 also issues a command to the target selection unit 1403. In response to this command, the target selection unit 1403 sets the target value T _SISO for receiving the signal transmitted from the single antenna to the gain calculation unit 1404. The target selection unit 1403 stores the target value T _SISO and a target value T _SISO described later.

Thus, the gain calculating unit 1404, a measurement result of the received power measurement section 505 compares the target value T _SISO, a gain as the measurement result of the received power measuring section 505 coincides with the target value T _SISO The variable gain amplifier 503 is set.

  Thereafter, the signal signal demodulator 1401 demodulates the LP signal, then demodulates the SIG1 signal, and outputs the demodulation result to the frame format information detector 1402. On the other hand, when the frame format information detection unit 1402 detects that the R unit is “1” from the demodulation result, the frame format information detection unit 1402 issues a command to the gain calculation unit 1404 and performs the second AGC control using the AGC signal. Let it begin. On the other hand, if it is “0”, no special command is given and new AGC control is not started.

If the R part is “1”, the frame format information detection unit 1402 also issues a command to the target selection unit 1403. In response to this command, the target selection unit 1403 sets the target value T _MIMO for receiving signals transmitted from the plurality of antennas Tx1 to Tx4 in the gain calculation unit 1404.

On the other hand, the gain calculation unit 1404 calculates the gain using the set target T _MIMO , and controls the gain of the variable gain amplifier 503 based on the measurement result of the reception power measurement unit 505 when the AGC signal is received. Then, the second AGC control is performed to prepare for reception of signals transmitted from a plurality of antennas.

Eventually, when the frame format information detection unit 1402 detects reception of the AGC signal from the demodulation result of the signal signal demodulation unit 1401, a command is given to the gain calculation unit 1404 to start the second AGC control using the AGC signal. In response to this command, the gain calculation unit 1404 compares the measurement result of the reception power measurement unit 505 with the target value T _MIMO when the AGC signal is received, and the measurement result of the reception power measurement unit 505 determines the target value. A gain that matches T _MIMO is set in the variable gain amplifier 503.

Therefore, when the transmission frame format shown in FIG. 13 is received, the target value is T _{SISO in} the first AGC control using the SP signal, and the second AGC control using the AGC signal is performed thereafter. The target value is T _MIMO . In general, when transmission is performed from a plurality of antennas, the dynamic range of the signal tends to increase as the number of transmission antennas increases, so that T _MIMO is set to a smaller value than T _SISO .

  With the configuration as described above, the gain of the variable gain amplifier 503 is controlled with an appropriate AGC target value regardless of whether a signal transmitted from a single antenna is received or a signal transmitted from a plurality of antennas. be able to.

  For this reason, as shown in FIG. 13, even when a radio frame is transmitted from a single antenna and a MIMO multiplexed part are mixed in the same radio frame, digital conversion can be appropriately performed. It is possible to perform high-precision digital conversion in each case, and high-accuracy reception performance can be exhibited.

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 constituent elements disclosed in the embodiment. Further, for example, a configuration in which some components are deleted from all the components shown in the embodiment is also conceivable. Furthermore, you may combine suitably the component described in different embodiment.
In addition, it goes without saying that the present invention can be similarly implemented even if various modifications are made without departing from the gist of the present invention.

The figure which shows the structure of the radio | wireless communications system to which the radio | wireless receiver concerning one Embodiment of this invention is applied. FIG. 2 is a circuit block diagram illustrating a configuration of the wireless transmitter illustrated in FIG. 1. The figure which shows an example of the transmission frame format transmitted from the wireless transmitter shown in FIG. The figure which shows an example of the transmission frame format transmitted from the wireless transmitter shown in FIG. 1 is a circuit block diagram showing a configuration of a wireless receiver according to an embodiment of the present invention. FIG. 6 is a circuit block diagram illustrating a configuration of a gain control unit of the wireless receiver illustrated in FIG. 5. The figure which shows an example of the output waveform of the matched filter of the gain control part shown in FIG. The figure which shows an example of the output waveform of the matched filter of the gain control part shown in FIG. The figure which shows the structure of the modification of the gain control part shown in FIG. The figure which shows an example of the transmission frame format transmitted from the wireless transmitter shown in FIG. The figure which shows the structure of the modification of the gain control part corresponding to the transmission frame format shown in FIG. The figure which shows an example of the output waveform of the matched filter of the gain control part shown in FIG. The figure which shows an example of the transmission frame format transmitted from the wireless transmitter shown in FIG. The figure which shows an example of the transmission frame format transmitted from the wireless transmitter shown in FIG. The figure which shows the structure of the modification of the gain control part corresponding to the transmission frame format shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 101-104 ... Wireless transmitter, 105 ... Wireless receiver, 201 ... Information bit stream production | generation part, 202 ... Serial parallel conversion part, 203 ... Transmission frame format determination part, 204-207 ... Digital modulation part, 208 ... Memory, 209- 212: Upconverter, 213-216: Transmitting antenna, 501: Receiving antenna, 502: Downconverter, 503: Variable gain amplifier, 504: A / D converter, 505: Received power measuring unit, 506: Gain control unit, 507 ... Digital signal processing unit, 601, 602 ... Matched filter, 603 ... Peak detection unit, 604 ... Frame format determination unit, 605 ... Reception timing detection unit, 606 ... Switch, 607 ... Target selection unit, 608 ... Gain calculation unit, 901 902 ... matched filter 903 ... peak detection 904... Frame format determination unit 905... Target selection unit 906... Reception timing detection unit 907... Gain calculation unit 908... Switch 1101 ... Matched filter 1102 ... Peak detection unit 1103 ... Signal signal reception timing Detection unit, 1104 ... reception timing detection unit, 1105 ... signal signal propagation path estimation unit, 1106 ... signal signal demodulation unit, 1107 ... frame format information detection unit, 1108 ... switch, 1109 ... target selection unit, 1110 ... gain calculation unit .

Claims (20)

In a wireless device that receives a wireless signal in which first information, second information, and third information are transmitted at different times,
Frequency converting means for down-converting the radio signal;
Amplifying means for amplifying the signal output by the frequency converting means;
A / D conversion means for A / D converting the signal output from the amplification means;
Multiplexing for detecting the spatial multiplexing number of the second information and the spatial multiplexing number of the third information based on a signal corresponding to the first information among signals output from the A / D conversion means. Number detection means;
The first gain is determined based on the spatial multiplexing number of the second information detected by the multiplexing number detection means, and the first gain is determined based on the spatial multiplexing number of the third information detected by the multiplexing number detection means. Gain determining means for determining a gain of 2;
Of the signals output from the frequency converting means, the signals corresponding to the second information are controlled so that the amplifying means performs with the first gain, and among the signals output from the frequency converting means A radio apparatus comprising: a control unit that controls the amplification unit to perform the signal corresponding to the third information with the second gain . The gain determining means determines a large value when the spatial multiplexing number detected by the multiplexing number detecting means is relatively small, and on the other hand, when the spatial multiplexing number detected by the multiplexing number detecting means is relatively large The wireless device according to claim 1, wherein a small value is determined. Furthermore, it comprises power detection means for detecting the received power of the radio signal from the output of the A / D conversion means,
The gain determination means determines the first gain based on the received power detected by the power detection means and the spatial multiplexing number of the second information detected by the multiplexing number detection means, and the power detection The radio apparatus according to claim 1, wherein the second gain is determined based on the received power detected by the means and the spatial multiplexing number of the third information detected by the multiplexing number detecting means . The first information is either a first waveform or a second waveform depending on the number of spatial multiplexing of the second information and the third information,
The multiple number detecting means includes
A first filter having an impulse response that matches the signal of the first waveform and to which the output of the A / D conversion means is input;
A second filter having an impulse response that matches the signal of the second waveform and to which the output of the A / D converter is input;
Of the output of the first filter and the output of the second filter, whether the waveform of the first information is the first waveform or the second waveform is detected by detecting the output from which the peak is obtained. Peak detecting means for detecting
2. The radio apparatus according to claim 1, further comprising: a format detection unit that detects a spatial multiplexing number of each of the second information and the third information based on a detection result of the peak detection unit. . Furthermore, a timing detection means is provided for detecting timings for receiving the second information and the third information, respectively, based on a signal corresponding to the first information out of the output of the A / D conversion means. ,
The radio apparatus according to claim 1, wherein the control unit switches a gain applied to the amplification unit based on the timing detected by the timing detection unit. The first information is a first waveform or a second waveform, depending on the number of spatial multiplexing of the second information and the third information,
The timing detection means includes
A first filter having an impulse response that matches the signal of the first waveform and to which the output of the A / D conversion means is input;
A second filter having an impulse response that matches the signal of the second waveform and to which the output of the A / D converter is input;
Peak detection means for detecting a peak included in the output of the first filter and a peak included in the output of the second filter;
Based on the timing of the peak of the peak detecting unit detects, according to claim 5, characterized in that it comprises a reception timing detecting means for detecting the respective reception timing of the second information and the third information Wireless devices. The timing detection means includes
A filter having an impulse response that matches a waveform formed by a signal corresponding to the first information, to which an output of the A / D converter is input;
A peak detecting means for detecting a peak included in the output of the filter;
Based on the timing of the peak of the peak detecting unit detects, according to claim 5, characterized in that it comprises a reception timing detecting means for detecting the respective reception timing of the second information and the third information Wireless devices. In a receiving circuit for receiving radio signals transmitted at different times, the first information, the second information, and the third information,
Frequency converting means for down-converting the radio signal;
Amplifying means for amplifying the signal output by the frequency converting means;
A / D conversion means for A / D converting the signal output from the amplification means;
Multiplexing for detecting the spatial multiplexing number of the second information and the spatial multiplexing number of the third information based on a signal corresponding to the first information among signals output from the A / D conversion means. Number detection means;
The first gain is determined based on the spatial multiplexing number of the second information detected by the multiplexing number detection means, and the first gain is determined based on the spatial multiplexing number of the third information detected by the multiplexing number detection means. Gain determining means for determining a gain of 2;
Of the signals output from the frequency converting means, the signals corresponding to the second information are controlled so that the amplifying means performs with the first gain, and among the signals output from the frequency converting means A receiving circuit comprising: control means for controlling the amplification means to perform the signal corresponding to the third information with the second gain . The gain determining means determines a large value when the spatial multiplexing number detected by the multiplexing number detecting means is relatively small, and on the other hand, when the spatial multiplexing number detected by the multiplexing number detecting means is relatively large The receiving circuit according to claim 8, wherein a small value is determined. Furthermore, it comprises power detection means for detecting the received power of the radio signal from the output of the A / D conversion means,
The gain determination means determines the first gain based on the received power detected by the power detection means and the spatial multiplexing number of the second information detected by the multiplexing number detection means, and the power detection 9. The receiving circuit according to claim 8 , wherein the second gain is determined based on the received power detected by the means and the spatial multiplexing number of the third information detected by the multiplexing number detecting means . The first information is either a first waveform or a second waveform depending on the number of spatial multiplexing of the second information and the third information,
The multiple number detecting means includes
A first filter having an impulse response that matches the signal of the first waveform and to which the output of the A / D conversion means is input;
A second filter having an impulse response that matches the signal of the second waveform and to which the output of the A / D converter is input;
Of the output of the first filter and the output of the second filter, whether the waveform of the first information is the first waveform or the second waveform is detected by detecting the output from which the peak is obtained. Peak detecting means for detecting
9. The receiving circuit according to claim 8 , further comprising format detecting means for detecting a spatial multiplexing number of each of the second information and the third information based on a detection result of the peak detecting means. . Furthermore, a timing detection means is provided for detecting timings for receiving the second information and the third information, respectively, based on a signal corresponding to the first information out of the output of the A / D conversion means. ,
9. The receiving circuit according to claim 8 , wherein the control means switches a gain applied to the amplifying means based on the timing detected by the timing detecting means. The first information is either a first waveform or a second waveform depending on the number of spatial multiplexing of the second information and the third information,
The timing detection means includes
A first filter having an impulse response that matches the signal of the first waveform and to which the output of the A / D conversion means is input;
A second filter having an impulse response that matches the signal of the second waveform and to which the output of the A / D converter is input;
Peak detection means for detecting a peak included in the output of the first filter and a peak included in the output of the second filter;
The peak detection means based on the timing of peaks detected is, according to claim 12, characterized in that it comprises a reception timing detecting means for detecting the respective reception timing of the second information and the third information Receiver circuit. The timing detection means includes
A filter having an impulse response that matches a waveform formed by a signal corresponding to the first information, to which an output of the A / D converter is input;
A peak detecting means for detecting a peak included in the output of the filter;
The peak detection means based on the timing of peaks detected is, according to claim 12, characterized in that it comprises a reception timing detecting means for detecting the respective reception timing of the second information and the third information Receiver circuit. In a radio apparatus that receives radio signals transmitted at different times from a signal for propagation path estimation and a data signal,
Frequency converting means for down-converting the radio signal;
Amplifying means for amplifying the signal output by the frequency converting means;
A / D conversion means for A / D converting the signal output from the amplification means;
Multiplex detection means for detecting the spatial multiplexing number of the propagation path estimation signal and the spatial multiplexing number of the data signal, respectively.
The first gain is determined based on the spatial multiplexing number of the propagation path estimation signal detected by the multiplexing number detection means, and the first gain is determined based on the spatial multiplexing number of the data signal detected by the multiplexing number detection means. Gain determining means for determining a gain of 2;
Of the signals output by the frequency conversion means, the propagation path estimation signal is controlled so that the amplification means performs the first gain, and the data of the signals output by the frequency conversion means. A radio apparatus comprising: control means for controlling the amplification means so as to perform the signal with the second gain . The gain determining means determines a large value when the spatial multiplexing number detected by the multiplexing number detecting means is relatively small, and on the other hand, when the spatial multiplexing number detected by the multiplexing number detecting means is relatively large 16. The wireless device according to claim 15, wherein a small value is determined for. Furthermore, it comprises power detection means for detecting the received power of the radio signal from the output of the A / D conversion means,
The gain determination means determines the first gain based on the received power detected by the power detection means and the spatial multiplexing number of the propagation path estimation signal detected by the multiplexing number detection means, and 16. The radio apparatus according to claim 15 , wherein the second gain is determined based on reception power detected by a power detection unit and a spatial multiplexing number of the data signal detected by the multiplexing number detection unit . In a radio apparatus that receives radio signals transmitted at different times from a signal for propagation path estimation and a data signal,
Frequency converting means for down-converting the radio signal;
Amplifying means for amplifying the signal output by the frequency converting means;
A / D conversion means for A / D converting the signal output from the amplification means;
Multiplex detection means for detecting the spatial multiplexing number of the propagation path estimation signal and the spatial multiplexing number of the data signal, respectively.
The first gain is determined based on the spatial multiplexing number of the propagation path estimation signal detected by the multiplexing number detection means, and the first gain is determined based on the spatial multiplexing number of the data signal detected by the multiplexing number detection means. Gain determining means for determining a gain of 2;
Of the signals output by the frequency conversion means, the propagation path estimation signal is controlled so that the amplification means performs the first gain, and the data of the signals output by the frequency conversion means. A receiving circuit comprising: control means for controlling the amplification means to perform the signal with the second gain . The gain determining means determines a large value when the spatial multiplexing number detected by the multiplexing number detecting means is relatively small, and on the other hand, when the spatial multiplexing number detected by the multiplexing number detecting means is relatively large The receiving circuit according to claim 18, wherein a small value is determined for. Furthermore, it comprises power detection means for detecting the received power of the radio signal from the output of the A / D conversion means,
The gain determination means determines the first gain based on the received power detected by the power detection means and the spatial multiplexing number of the propagation path estimation signal detected by the multiplexing number detection means, and 19. The receiving circuit according to claim 18 , wherein the second gain is determined based on the received power detected by the power detecting means and the spatial multiplexing number of the data signal detected by the multiplexing number detecting means .

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