JP2005151249A - Wireless receiver and method of amplifying received signal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an error from occurring in measurement of RSCP, ISCP or the like. <P>SOLUTION: A control unit 104 performs initial synchronization of a digital signal S1 output from an A/D converter 103; detects a reception timing, a spreading code or the like; and outputs the reception timing, the spreading code or the like to a finger 106. In addition, the control unit 104 outputs frame format information of a downstream line informed from a higher level station to an AGC 105. The AGC 105 measures reception power of the signal S1 under the control of the control unit 104, and also calculates the gain to control a reception amplifier in a wireless section 102. An RSCP measurement section 109 and an ISCP measurement section 110 measure the RSCP and ISCP respectively from a despreading signal output from the finger 106 or a RAKE synthesizer 107, a phase estimated value, a post-synchronous detection signal, a rake synthesis signal or the like. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a radio reception apparatus employing a method such as code division multiple access (CDMA) and a received signal amplification method used in the apparatus.

  FIG. 7 is a block diagram showing a configuration of a wireless reception apparatus adopting a conventional CDMA system (see, for example, Patent Document 1).

  The CDMA signal received by the antenna 11 becomes an intermediate frequency in the receiver front stage 12, is amplified by an AGC (Automatic Gain Control) amplifier 13 whose gain can be varied by a control voltage, and then is demodulated by the demodulator 14. Demodulated to a signal. The baseband signal is limited to a band corresponding to one channel by a low-pass filter (LPF) 15 and quantized by an A / D converter 16. The power calculator 17 adds an arbitrary time power from the beginning of the slot to the quantized signal and averages it, and transmits this average power to the controller 18.

  The control unit 18 calculates a “time to be controlled” described later, and sends control data to the D / A converter 19 when the predetermined time comes. That is, the control unit 18 calculates “time to be controlled” based on the average power obtained by the power calculation unit 17, and outputs control data representing the control amount at a timing (time) according to the control amount. The data is sent to the A converter 19.

  The D / A converter 19 converts the control data into an analog control signal. The control signal is waveform-shaped by the low-pass filter 20 and gives a control voltage to the AGC amplifier 13. The slot head information is transmitted from the despreading unit 21 to the power calculation unit 17. Further, the power calculation unit 17 may calculate the power from the middle of the slot instead of from the beginning of the slot.

With the above configuration, the conventional radio receiving apparatus calculates “time to be controlled” and transmits control data at a timing according to the control amount. That is, the control start time of AGC is advanced in consideration of the time required for the voltage rise. This makes it possible to adjust the time to reach the target voltage so as to coincide with the head of the next slot.
Japanese Patent Laid-Open No. 2001-111523 (FIGS. 1, 2, and 4)

  However, in order to advance the AGC control start time in the above-described wireless reception device, the reception power changes with the gain update of the AGC amplifier from the second half of the received signal slot. On the other hand, in this region (time zone), RSCP (Received Signal Code Power) and ISCP (Interference Signal Code Power) used for SIR (Signal-to-Interference Ratio) measurement are measured. There are target pilot symbols and the like. Therefore, there is a problem that an error occurs in the RSCP and ISCP level measurement values as the gain of the AGC amplifier is updated.

  In the conventional radio receiving apparatus, the measurement period of the received power that is a reference for calculating the AGC gain is in the beginning or middle of the slot, but is not specifically determined. On the other hand, in a CDMA communication system, when a downlink is controlled by DTX (Discontinuous Transmission), during DTX, a DPCCH (Dedicated Physical Control Channel) is transmitted, whereas a DPDCH (Dedicated Physical Data Channel) is transmitted. ) Is not sent. Therefore, when the period during which the DPDCH is transmitted is included in the measurement period of the received power that is a reference for calculating the AGC gain, there is a problem that AGC control cannot be performed accurately during DTX.

  The present invention has been made in view of the above points, and prevents occurrence of errors in measurement of various powers (RSCP, ISCP, etc.) used for reception quality measurement, and accurately performs AGC control even during DTX. It is an object of the present invention to provide a radio reception apparatus capable of improving reception performance and a received signal amplification method used in the apparatus.

  The wireless receiver of the present invention measures the power of the received signal, amplifies the received signal with an amplification gain according to the measured power, an acquisition means for acquiring the frame format information of the received signal, Based on the frame format information acquired by the acquisition unit, one or both of a period during which the amplification unit updates the amplification gain according to the measured power and a period during which the amplification unit measures power is determined. And a determination means.

  According to this configuration, in order to determine the AGC gain update period or the reception power measurement period that serves as a reference for AGC gain calculation based on the frame format information of the received signal, for example, various powers used for reception quality measurement When measuring (RSCP, ISCP, etc.), it is possible to prevent the occurrence of errors, and to perform AGC control accurately even during DTX. Therefore, reception performance can be improved.

  The radio reception apparatus of the present invention further includes a calculation unit that calculates power used for calculation of reception quality in the above configuration, and the determination unit includes power used by the calculation unit for calculation of reception quality. The amplification means determines a period other than the period for calculating the amplification gain as a period for updating the amplification gain.

  The radio reception apparatus of the present invention employs a configuration in which the power used for calculating the reception quality is RSCP (Received Signal Code Power) and ISCP (Interference Signal Code Power) in the above configuration.

  According to these configurations, the RSCP and ISCP measurement target symbols are specified based on the frame format information of the received signal, and AGC control is performed so that the AGC gain update timing is out of the RSCP and ISCP measurement periods. It is possible to prevent the occurrence of errors in the measurement of RSCP and ISCP, and to improve the reception performance.

  The radio receiving apparatus of the present invention further comprises specifying means for specifying a transmission period of a DPCCH signal from the frame format information acquired by the acquiring means in the above configuration, and the determining means is specified by the specifying means. Further, a configuration is adopted in which a predetermined period within the transmission period of the DPCCH signal is determined as a period during which the amplification means measures power.

  According to this configuration, even during DTX, the period during which the DPCCH is transmitted in the received signal is specified. Therefore, AGC control can be performed based on the received signal during this period, and reception performance can be improved. .

  A communication terminal apparatus according to the present invention employs a configuration including any one of the radio reception apparatuses described above.

  According to this configuration, it is possible to provide a communication terminal device having the same operational effects as described above.

  The reception signal amplification method of the present invention acquires a measurement step of measuring the power of the reception signal, an amplification step of amplifying the reception signal with an amplification gain corresponding to the measured power, and frame format information of the reception signal A determination to determine one or both of an acquisition step and a period in which amplification gain is updated according to power in the amplification step and a period in which power is measured in the measurement step based on the acquired frame format information Steps.

  The reception signal amplification program of the present invention acquires a measurement step of measuring the power of the reception signal, an amplification step of amplifying the reception signal with an amplification gain corresponding to the measured power, and frame format information of the reception signal A determination to determine one or both of an acquisition step and a period in which amplification gain is updated according to power in the amplification step and a period in which power is measured in the measurement step based on the acquired frame format information And let the computer execute the steps.

  According to the method and the program, the AGC gain update period or the reception power measurement period that is a reference for calculating the AGC gain is determined based on the frame format information of the received signal. Generation of errors can be prevented in measurement of various powers (RSCP, ISCP, etc.), and AGC control can be performed accurately even during DTX, so that reception performance can be improved.

  As described above, according to the present invention, it is possible to prevent occurrence of errors in measurement of various powers (RSCP, ISCP, etc.) used for reception quality measurement, and to perform AGC control accurately even during DTX. Therefore, the reception performance can be improved.

  The essence of the present invention is to determine an AGC gain update period or a reception power measurement period that serves as a reference for AGC gain calculation based on frame format information of the received signal.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Here, as a radio receiving apparatus, a communication terminal that receives a downlink CPICH (Common Pilot Channel) and DPCH (Dedicated Physical Channel) transmitted from a base station in a CDMA communication system will be described as an example.

(Embodiment 1)
FIG. 1 is a block diagram showing the main configuration of a radio reception apparatus according to Embodiment 1 of the present invention.

  The radio receiving apparatus according to the present embodiment includes an antenna 101, a radio unit 102, an A / D converter 103, a control unit 104, an AGC unit 105, finger units 106 (106-1 to 106-n), a RAKE combining unit 107, A channel decoder 108, an RSCP measurement unit 109, an ISCP measurement unit 110, and an SIR measurement unit 111 are included.

  Each unit of the radio reception apparatus according to the present embodiment performs the following operation.

  Radio section 102 performs amplification and demodulation processing on the received signal received by antenna 101, and outputs the obtained baseband analog signal. The A / D converter 103 A / D converts a baseband analog signal and outputs a digital signal. The finger unit 106 performs despreading and synchronous detection of the received digital signal using the timing and spreading code notified from the control unit 104. The RAKE combining unit 107 rake combines the signals after synchronous detection output from each finger unit 106. The channel decoder 108 performs processing such as frame decomposition and error correction decoding on the rake combined signal to obtain received data.

  On the other hand, the control unit 104 performs initial synchronization using a matched filter or the like from the digital signal S1 output from the A / D converter 103, and detects reception timing, spreading code, and the like. Then, according to the detection result, a finger corresponding to the number of demodulation channels is selected from the finger unit 106 (finger assignment), and a control signal S3 indicating reception timing, spreading code, etc. is output to these. In addition to the above detection result, control unit 104 outputs downlink frame format information notified from the higher station to AGC unit 105 via control signal S2.

  Based on the control signal S2 output from the control unit 104, the AGC unit 105 measures (calculates) the received power of the digital signal S1 output from the A / D converter 103 at a specified timing, and also specifies the specified signal. The gain is calculated at the timing, and the reception amplifier in the wireless unit 102 is controlled (amplifier control signal S4).

  The RSCP measurement unit 109 and the ISCP measurement unit 110 measure the RSCP and ISCP levels from the despread signal, the phase estimation value, the signal after synchronous detection, the rake composite signal, and the like output from the finger unit 106, respectively. Note that the RSCP measuring unit 109 and the ISCP measuring unit 110 may measure the RSCP and ISCP levels from the output of the RAKE combining unit 107 depending on the algorithm used. The SIR measurement unit 111 calculates the ratio of the outputs of the RSCP measurement unit 109 and the ISCP measurement unit 110, and obtains an SIR value.

  Next, the calculation process of the AGC gain of the reception amplifier of the wireless reception apparatus having the above configuration will be described.

  The control unit 104 determines the RSCP and ISCP measurement periods to be performed in the RSCP measurement unit 109 and the ISCP measurement unit 110 based on the downlink frame format information notified from the upper station. Then, according to the determination result, the control unit 104 generates a control signal S2 including an operation control signal for controlling the power measurement (calculation) operation of the AGC unit 105 and an update timing signal for controlling the gain update timing. Output to. In the operation control signal and the update timing signal, the RSCP and ISCP measurement periods performed in the RSCP measurement unit 109 and the ISCP measurement unit 110 overlap with the gain fluctuation period due to the update of the AGC gain control value performed in the AGC unit 105. This is a control signal for controlling the operation of the AGC unit 105 so as not to occur.

  Next, the AGC unit 105 that has received the control signal S2 from the control unit 104 performs the following processing.

  FIG. 2 is a block diagram illustrating a main configuration of the AGC unit 105. The AGC unit 105 includes a power accumulation unit 112, a division unit 113, a subtractor 114, an error accumulation unit 115, a reception amplifier control unit 116, and a D / A converter 117.

  The power accumulating unit 112 calculates received power from the output S1 of the A / D converter 103 during the period in which the operation control signal output from the control unit 104 indicates ON, and accumulates the calculated value. Division unit 113 calculates the average received power by dividing the output of power accumulation unit 112 by the number of accumulated data. The subtractor 114 calculates an error by obtaining a difference between the average received power output from the division unit 113 and a preset target convergence value, and outputs this. The error accumulating unit 115 accumulates the error output from the subtracter 114. The reception amplifier control unit 116 obtains an error accumulation value from the error accumulation unit 115 when the update timing signal output from the control unit 104 is turned on, and from this value, the reception amplifier in the radio unit 102 A gain to be used is calculated, and a gain control value based on this gain is output to the D / A converter 117. The D / A converter 117 performs D / A conversion on this gain control value, and outputs the obtained analog signal amplifier control signal S 4 to the reception amplifier in the radio unit 102.

  FIG. 3 is a diagram showing in the frame structure of the received signal when the AGC gain calculation is actually performed, that is, when the AGC gain can be updated. In this figure, the symbols to be measured by ISCP and RSCP are indicated by hatching. Therefore, the timing at which the AGC gain can be updated is any symbol within a period that does not include a diagonal line. Here, an example is shown in which the gain update is performed at the head of the slot.

  Thus, according to the present embodiment, control section 104 specifies symbols to be measured for RSCP and ISCP based on downlink physical channel information (downlink frame format information), and updates timing of AGC gain. Since the AGC unit 105 is controlled so as to deviate from the RSCP and ISCP measurement periods, it is possible to prevent the occurrence of errors in the RSCP and ISCP measurements and improve the reception performance.

(Embodiment 2)
A feature of the second embodiment of the present invention is that a region including a dedicated physical data channel (DPDCH) in a received signal is not included in a measurement (calculation) period of received power that is a reference for AGC gain calculation. The period during which the Dedicated Physical Control Channel) is transmitted is specified, and the received power is measured during this period.

  The radio reception apparatus according to the present embodiment has the same basic configuration as that of the radio reception apparatus shown in FIG. The configuration of the control unit 104 is different from the radio reception device shown in FIG.

  FIG. 4 is a block diagram illustrating a main configuration of the control signal generation circuit 201 included in the control unit 104. This control signal generation circuit 201 includes counters 202-1 and 202-2 (generally simply 202) and an AND circuit 203, and generates an operation control signal to the AGC unit 105.

  Each part of the control signal generation circuit 201 performs the following operation.

  Counter upper limit value 1 and counter upper limit value 2 are input to counter 202-1 and counter 202-2, respectively. The counter upper limit value 1 is set to the first data portion of the DPCH, that is, the number of symbols (Ndata1) of the first DPDCH (Dedicated Physical Data Channel). The counter upper limit value 2 is a symbol obtained by adding the number of symbols in the first control data part of the DPCH, that is, the TPC (Transmission Power Control) part and TFCI (Transport Format Combination Indicator) part of the first DPCCH to the above Ndata1 A number (NData1 + Ntpc + Ntfci) is set.

  A clock signal is input to the counter 202 (202-1 and 202-2). The clock signal is a signal generated at regular intervals (here, every symbol) by an internal clock (oscillator), and the count value of the counter 202 is incremented by 1 each time the clock signal is input. The counter 202 continues to output 0 until the counter value reaches the counter upper limit value, and when the count value reaches the counter upper limit value, the counter 202 outputs 1.

  Further, a reset signal is input to the counter 202 for each slot. When a reset signal is input, the counter 202 resets the count value to 0 and outputs 0.

  The logical product circuit 203 outputs a negative logical product of the outputs of the counters 202-1 and 202-2. The control unit 104 outputs this logical product to the AGC unit 105.

  FIG. 5 is a diagram showing a frame structure of DPCH.

  As shown in this figure, DPCH has a frame configuration in which DPDCH and DPCCH are arranged in a time division manner. Whether the data after a predetermined symbol counted from the head of the slot is DPDCH or DPCCH, In addition, it is possible to uniquely determine how many parts of the DPCCH correspond. Therefore, in the present embodiment, the position of the tip of the first DPCCH can be detected by setting the counter upper limit value 1 to Ndata1. Further, by setting the counter upper limit value 2 as Ndata1 + Ntpc + Ntfci, the position of the end of the first DPCCH can be detected.

  Here, since the case where the number of installed counters 202 is 2 has been described as an example, only the front end and the end of the first DPCCH can be detected, but by increasing the number of installed counters 202, for example, it is located in the second half of the slot. A section of a pilot symbol (DPCCH) can also be included in the power measurement target.

  FIG. 6 is a diagram showing the relationship between the control signal generated by the control signal generation circuit 201 having the above configuration and the DPCH. Here, it is assumed that the slot format of DPCH is 8, and the TPC symbols and pilot symbols are arranged at the positions of the hatched lines in the figure.

  Here, three counters 202 are installed, and TPC symbols and pilot symbols can be detected (specifically, the top and end of the TPC symbol and the top of the pilot symbol can be detected). Is set.

  Since the reset signal is input to the counter 202 at time t1, the counter value is 0. At time t2, since the clock signal has been oscillated three times until this point in time, the counter value becomes 3, reaches the counter upper limit value 1 (set value is 3), and the leading edge of the TPC symbol is detected. At time t3, the counter value reaches the counter upper limit value 2 (set value is 4), and the end of the TPC symbol is detected. At time t4, the counter value reaches the counter upper limit value 3, and the tip of the pilot symbol is detected. At time t5, since a reset signal is input to the counter 202, the counter value is reset to zero.

  According to these detection results, operation control signals C1 to C3 are generated as shown in the figure. Here, three types are shown: when the power measurement target is a TPC symbol (C1), when it is a pilot symbol (C3), and when it is both (C2). Further, a TFCI symbol may be added to the power measurement target.

  As described above, according to the present embodiment, even during DTX, the control signal generation circuit 201 in the control unit 104 specifies the period during which the DPCCH is transmitted in the received signal. AGC control can be performed based on the measured power of the received signal, and reception performance can be improved.

  The radio reception apparatus according to the present invention is not limited to the first and second embodiments, and can be implemented with various modifications. For example, Embodiments 1 and 2 can be implemented in combination as appropriate.

  The radio receiving apparatus according to the present invention can be mounted on a communication terminal apparatus and a base station apparatus using a cellular system or the like, thereby providing a communication terminal apparatus and a base station apparatus having the same effects as described above. can do.

  Here, the case where the present invention is configured by hardware has been described as an example, but the present invention can also be realized by software.

  The radio reception apparatus according to the present invention has an effect of improving reception performance, and is useful as a reception apparatus or the like adopting a CDMA system.

FIG. 2 is a block diagram showing a main configuration of a radio reception apparatus according to Embodiment 1 FIG. 2 is a block diagram showing the main configuration of the AGC unit according to the first embodiment. The figure which showed when the timing which can update an AGC gain is in the frame structure of a received signal FIG. 3 is a block diagram illustrating a main configuration of a control signal generation circuit according to a second embodiment. The figure which shows the flame | frame structure of DPCH The figure which shows the relationship between the control signal produced | generated by the control signal production | generation circuit based on Embodiment 2, and DPCH. A block diagram showing a configuration of a radio receiving apparatus adopting a conventional CDMA system

Explanation of symbols

DESCRIPTION OF SYMBOLS 102 Radio | wireless part 104 Control part 105 AGC part 109 RSCP measurement part 110 ISCP measurement part 111 SIR measurement part 112 Power accumulation part 113 Division part 114 Subtractor 115 Error accumulation part 116 Reception amplifier control part 117 D / A converter 201 Control signal generation circuit 202-1, 202-2 counter 203 AND circuit

Claims (7)

Amplifying means for measuring the power of the received signal and amplifying the received signal with an amplification gain according to the measured power;
Obtaining means for obtaining frame format information of the received signal;
Based on the frame format information acquired by the acquisition unit, one or both of a period during which the amplification unit updates the amplification gain according to the measured power and a period during which the amplification unit measures power is determined. A determination means;
A wireless receiver characterized by comprising: A calculation means for calculating power used for calculating reception quality;
The determining means includes
Determining a period other than a period in which the calculation means calculates power used for calculation of reception quality as a period in which the amplification means updates the amplification gain;
The wireless receiver according to claim 1. The power used to calculate the reception quality is
RSCP (Received Signal Code Power) and ISCP (Interference Signal Code Power),
The radio reception apparatus according to claim 2. Further comprising specifying means for specifying the transmission period of the DPCCH signal from the frame format information acquired by the acquiring means;
The determining means includes
Determining a predetermined period within the transmission period of the DPCCH signal specified by the specifying means as a period during which the amplification means measures power;
The wireless receiver according to claim 1.   A communication terminal device comprising the wireless reception device according to claim 1. A measurement step for measuring the power of the received signal;
An amplification step of amplifying the received signal with an amplification gain corresponding to the measured power;
Obtaining the frame format information of the received signal;
A determination step of determining one or both of a period during which amplification gain is updated according to power in the amplification step and a period during which power is measured in the measurement step based on the acquired frame format information;
A received signal amplification method comprising: A measurement step for measuring the power of the received signal;
An amplification step of amplifying the received signal with an amplification gain corresponding to the measured power;
Obtaining the frame format information of the received signal;
A determination step of determining one or both of a period during which amplification gain is updated according to power in the amplification step and a period during which power is measured in the measurement step based on the acquired frame format information;
A received signal amplification program for causing a computer to execute

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