JP2005175810A - Device for measuring desired signal versus interference signal power ratio, radio communication device, and base station device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide SIR measuring equipment capable of accurately measuring the SIR of a reception signal by simple signal processing, to provide a radio communication device having the SIR measuring equipment, and to provide a base station device capable of accurately measuring SIR for HARQ-ACK even if especially using the base station for W-CDMA radio communication. <P>SOLUTION: An SIR calculation section 106 calculates the SIR of the reception signal after RAKE synthesis, by dividing RSCP inputted from a desired signal power calculator 103 by ISCP inputted from an interference signal power corrector 105. Then, the SIR calculator 106 inputs the calculated SIR to a configuration section, or the like for decoding HARQ-ACK (not shown). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a radio communication device typified by a mobile phone or a base station device, its base station device, and a device that can be mounted on the radio communication device, and uses the power of a desired signal contained in a received signal as a numerator. A signal-to-interference power ratio measurement apparatus (hereinafter referred to as “SIR measurement”) that measures a signal-to-interference signal power ratio (SIR) using the power of an interference signal included in a signal as a denominator. May be referred to as an “apparatus”).

  Conventionally, in wireless communication using a quadrature modulation method, a technique in which a wireless communication apparatus performs SIR measurement based on a received signal after RAKE combining has been studied (for example, see Patent Document 1). In the technique described in Patent Document 1, a known data pattern included in a received signal after RAKE combining is averaged, and this averaged known data pattern (hereinafter, sometimes referred to as “average symbol”). The desired signal power (RSCP) is the desired signal power (RSCP), the dispersion value for the known data pattern included in the received signal after RAKE combining is the interference signal power (ISCP: Interference Signal Code Power), and RSCP is The SIR of the received signal is calculated by obtaining a ratio with the numerator and ISCP as the denominator.

  FIG. 5 is a diagram showing a general configuration of an SIR measurement apparatus used in the technique described in Patent Document 1, and demodulates a reception signal modulated by the QPSK method and in-phase the received signal after demodulation. FIG. 2 is a block diagram showing a configuration of an SIR measurement apparatus 10 that measures the SIR of a received signal after RAKE combining a component (Ich component) and a quadrature component (Qch component). The SIR measurement apparatus 10 includes a known pattern generation unit 11, an average symbol calculation unit 12, a desired signal power calculation unit 13, an interference signal power calculation unit 14, and an SIR calculation unit 15.

  The known pattern generation unit 11 generates a data pattern that is known between the transmission-side wireless communication device and the reception-side wireless communication device, and inputs the generated known data pattern to the average symbol calculation unit 12.

  The average symbol calculation unit 12 obtains N (N is an arbitrary integer) symbols for a known pattern for each of the in-phase component and the quadrature component of the received signal after RAKE synthesis input from a received signal processing unit (not shown). An average symbol is generated by multiplying a known data pattern input from the generation unit 11 to match quadrants and then averaging. The average symbol calculation unit 12 individually inputs the generated average symbol of the in-phase component and the generated average symbol of the orthogonal component to the desired signal power calculation unit 13 and the interference signal power calculation unit 14, respectively.

The desired signal power calculation unit 13 receives the average symbol power (rscp.i ² ) of the in-phase component and the quadrature component of the average symbol of the in-phase component and the average symbol of the quadrature component input from the average symbol calculation unit 12. The RSCP is calculated by measuring the average symbol power (rscp.q ² ) and combining the measured powers. Then, the desired signal power calculation unit 13 inputs the calculated RSCP to the SIR calculation unit 15.

  The interference signal power calculation unit 14 receives an in-phase component and a quadrature component of the received signal after RAKE combining input from a reception signal processing unit (not shown), and an average symbol and quadrature of the in-phase component input from the average symbol calculation unit 12. Based on the average symbol of the component, the variance value of the known data pattern of the in-phase component and the variance value of the known data pattern of the quadrature component are calculated, and the ISCP is calculated by adding the two calculated variance values To do. Then, the interference signal power calculation unit 14 inputs the calculated ISCP to the SIR calculation unit 15.

  The SIR calculation unit 15 calculates the SIR of the received signal after RAKE combining by dividing the RSCP input from the desired signal power calculation unit 13 by the ISCP input from the interference signal power calculation unit 14.

  The procedure for calculating the SIR of the received signal in the SIR measuring apparatus 10 will be described more specifically. Here, the in-phase component of the known data pattern included in the received signal after RAKE combining is represented by Rx [n]. i, the same orthogonal component is represented by Rx [n]. Assuming that the integer used in the calculation of q and the average symbol is N, and the known data pattern is ref [n], RSCP represents the power of the average symbol included in the received signal after RAKE combining as 1), it is calculated | required by Formula (2) and Formula (3).

ＲＳＣＰ＝ｒｓｃｐ．ｉ^２＋ｒｓｃｐ．ｑ^２ ・・・（３）

RSCP = rscp. i ² + rscp. q ² (3)

  Here, Equations (1) and (2) are calculated by the average symbol calculation unit 12, and Equation (3) is calculated by the desired signal power calculation unit 13.

  Also, the ISCP uses the in-phase component of ISCP as iscp [n] .n as a dispersion value of a known data pattern included in the received signal after RAKE synthesis. i and its orthogonal components are iscp [n]. If it is set to q, it will obtain | require by following formula (4), Formula (5), and Formula (6). It should be noted that the equations (4), (5), and (6) are all calculated by the interference signal power calculation unit 14.

iscp [n]. i = ref [n] × Rx [n]. i-rscp. i (4)
iscp [n]. q = ref [n] × Rx [n]. q-rscp. q (5)

  Then, the SIR of the received signal after RAKE synthesis is obtained by the following equation (7) as a ratio with RSCP as the numerator and ISCP as the denominator. The following equation (7) is calculated by the SIR calculation unit 15.

  As described above, in the technique described in Patent Document 1, the SIR of the received signal is measured using both the in-phase component and the quadrature component of the received signal after RAKE combining.

Meanwhile, on the other hand, an attempt has been made to measure the SIR of the received signal using only either the in-phase component or the quadrature component of the received signal (see, for example, Patent Document 2).
JP 2003-32168 A JP 2002-290344 A

  However, in the technique described in Patent Document 1, since SIR cannot be measured unless both the in-phase component and the quadrature component of the received signal after RAKE combining are used, the signal processing of the received signal in the SIR measuring device is somewhat There is a problem that becomes complicated.

  Further, in the technique described in Patent Document 1, for example, in the case of W-CDMA wireless communication, the SIR of the received signal of the uplink HS-DPCCH (Dedicated Physical Control Channel (Uplink) for HS-DSCH) is measured. In addition, since the same spreading code is used in another channel orthogonal to the HS-DPCCH, the reception signal of this other channel becomes an interference signal for the reception signal of the HS-DPCCH. There is a problem that the SIR of the signal cannot be measured accurately. Specifically, in 3GPP (3rd Generation Partnership Project), in the uplink channel in W-CDMA wireless communication, DPDCH (Dedicated Physical Data CHannel) is mapped as an in-phase component and HS-DPCCH is mapped as an orthogonal component. It is specified that the same spreading code is used for the channel. Therefore, when measuring SIR for HARQ-ACK (Hybrid-ARQ Acknowledgment) transmitted on HS-DPCCH, DPDCH, which is an in-phase component, interferes with HARQ-ACK, so that SIR is accurately measured. There is a problem that it is not possible.

  Furthermore, in the technique described in Patent Document 2, RSCP and ISCP are calculated using a reception signal that has been despread by the SIR measurement device and is not RAKE-combined. Therefore, the reception signal includes fading and AFC. (Automatic Freqency Control) Since phase rotation occurs due to the influence of residue, etc., it is theoretically difficult to accurately calculate RSCP and ISCP using only one of the in-phase component and quadrature component of the received signal. There is a problem that.

  The present invention has been made in view of the above points, and an SIR measuring apparatus capable of accurately measuring the SIR of a received signal by simple signal processing, and a wireless communication apparatus equipped with the SIR measuring apparatus, particularly a W- An object of the present invention is to provide a base station apparatus that can accurately measure the SIR of HARQ-ACK even when used for CDMA wireless communication.

  A desired signal to interference signal power ratio measuring apparatus according to the present invention calculates desired signal power included in a received signal based on either the in-phase component or the quadrature component of the received signal after RAKE combining. A calculation means; an interference signal power calculation means for calculating power of an interference signal included in the reception signal based on either the in-phase component or the quadrature component of the reception signal after RAKE combining; A desired signal-to-interference signal power ratio calculating unit that calculates a ratio using the desired signal power as a numerator and the interference signal power calculated as a denominator is employed.

  According to this configuration, since only the in-phase component or the quadrature component of the received signal after RAKE combining is used to calculate the RSCP and ISCP of the received signal, simple signal processing is performed on the received signal. The SIR of the received signal can be accurately measured only by this.

  The desired signal to interference signal power ratio measuring apparatus according to the present invention is the above-described invention, wherein the interference signal power calculation means is based on either the in-phase component or the quadrature component of the received signal after RAKE combining. The interference signal power is calculated by correcting the interference value of the interference signal included in the received signal by twice.

  According to this configuration, in addition to the effect of the present invention, since the calculated value of ISCP is only corrected by a factor of 2, the SIR accuracy can be increased by simply performing simple signal processing on the received signal after RAKE combining. It can be further enhanced.

  The radio communication apparatus according to the present invention employs a configuration including the desired signal to interference signal power ratio measuring apparatus according to the present invention.

  According to this configuration, since the SIR measurement device according to the present invention is provided, it is not necessary to perform complicated signal processing on the received signal, so that a wireless communication device with high response speed and low power consumption can be obtained. It is done.

  A base station apparatus according to the present invention is the wireless communication apparatus according to the present invention, wherein the desired signal power calculation means calculates the power of the desired signal included in the received signal of the HS-DPCCH after RAKE combining. The interference signal power calculating means calculates the power of the interference signal included in the received signal of the HS-DPCCH after RAKE combining.

  According to this configuration, since the RSCP and ISCP of the received signal are calculated based on either the in-phase component or the quadrature component of the received signal after RAKE combining, the base usable for W-CDMA wireless communication A station apparatus can be provided.

  The base station apparatus according to the present invention employs a configuration in which the desired signal-to-interference signal power ratio calculated by the desired signal-to-interference signal power ratio calculating unit is used for decoding HARQ-ACK in the above-described invention.

  According to this configuration, in addition to the effects of the present invention, the SIR calculated by the SIR measuring apparatus according to the present invention is used for decoding HARQ-ACK, so that the decoding performance can be improved.

  According to the present invention, since the RSCP and ISCP of the received signal are calculated based on either the in-phase component or the quadrature component of the received signal after RAKE combining, the in-phase component and the quadrature component interfere with each other. Even in this case, the SIR of the received signal can be accurately measured by simple signal processing. Therefore, according to the present invention, the SIR of HARQ-ACK in W-CDMA wireless communication can be accurately measured.

  The gist of the present invention is to measure the SIR of the received signal based only on either the in-phase component or the quadrature component of the received signal after RAKE synthesis.

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

  FIG. 1 is a block diagram showing a configuration of an SIR measuring apparatus 100 according to the present embodiment. The SIR measurement device 100 is normally used by being incorporated in a mobile communication terminal device such as a mobile phone or a wireless communication device represented by a base station device. In the present embodiment, it is assumed that only the quadrature component (Qch component) of the received signal after RAKE combining is input to SIR measurement apparatus 100.

  The SIR measurement apparatus 100 includes a known pattern generation unit 101, an average symbol calculation unit 102, a desired signal power calculation unit 103, an interference signal power calculation unit 104, an interference signal power correction unit 105, and an SIR calculation unit 106.

  The known pattern generation unit 101 generates a data pattern that is known between the transmission-side wireless communication device and the reception-side wireless communication device, and inputs the generated known data pattern to the average symbol calculation unit 102.

  The average symbol calculation unit 102 receives, from the known pattern generation unit 101, N (N is an arbitrary integer) symbols of orthogonal components of the RAKE-combined reception signal input from a reception signal processing unit (not shown). An average symbol is generated by multiplying the known data pattern to match the quadrant and then averaging. The average symbol calculation unit 12 sequentially inputs the generated average symbol of orthogonal components to the desired signal power calculation unit 103 and the interference signal power calculation unit 104.

  Desired signal power calculation section 103 calculates RSCP by measuring the average symbol power of orthogonal components input from average symbol calculation section 102, and inputs the calculated RSCP to SIR calculation section 106.

  Interference signal power calculation section 104 is based on the orthogonal component of the received signal after RAKE synthesis input from a reception signal processing section (not shown) and the average symbol of the orthogonal component input from average symbol calculation section 102. The dispersion value of the known data pattern of the orthogonal component, that is, ISCP ′ is calculated, and the calculated ISCP ′ is input to the interference signal power correcting unit 105.

  Interference signal power correction section 105 corrects ISCP ′ input from interference signal power calculation section 104 by a factor of 2, and inputs the corrected ISCP to SIR calculation section 106.

  The SIR calculation unit 106 calculates the SIR of the received signal after RAKE combining by dividing the RSCP input from the desired signal power calculation unit 103 by the ISCP input from the interference signal power correction unit 105. Then, the SIR calculation unit 106 inputs the calculated SIR to a component that performs HARQ-ACK decoding processing (not shown).

  Further, the constituent unit that performs the HARQ-ACK decoding process (not shown) uses the SIR input from the SIR calculation unit 106 to determine whether the HARQ-ACK is ACK or NACK by DTX (no signal). It is determined whether there is any. For example, by comparing the size of the SIR input from the SIR calculation unit 106 with a predetermined threshold value, it is possible to improve the determination accuracy of whether or not the HARQ-ACK is DTX (no signal).

  Next, the procedure for calculating the SIR of the received signal in the SIR measuring apparatus 100 will be described more specifically. In RAKE synthesis, synchronous detection of the received signal is inevitably performed. Therefore, in the received signal after RAKE synthesis, phase rotation derived from fading or the like is corrected by synchronous detection and hardly remains. Therefore, when measuring the SIR based on the received signal after RAKE combining, it can be assumed that most of the desired signal exists on the orthogonal component. If this assumption is made, rscp. Since i = 0, RSCP is obtained by the following equation (8) from equation (3). Note that the rscp. q is calculated by the average symbol calculation unit 102, and its RSCP is calculated by the desired signal power calculation unit 103.

RSCP = rscp. q ² (8)

  On the other hand, even if it is a received signal after RAKE combining, it can be assumed that interference signals such as noise are uniformly distributed on both the in-phase component and the quadrature component, and therefore the following equation (9) holds.

  Therefore, the equation (9) is applied to the equation (6). First, the interference signal power calculation unit 104 calculates ISCP ′ by the following equation (10), and then the interference signal power correction unit 105 calculates the following equation (11). The ISCP can be calculated by correcting ISCP ′ by a factor of two.

ＩＳＣＰ＝ＩＳＣＰ´×２ ・・・（１１）

ISCP = ISCP ′ × 2 (11)

  Then, the SIR calculation unit 106 calculates the SIR based only on the orthogonal component of the received signal after RAKE combining by dividing the RSCP calculated by the equation (8) by the ISCP calculated by the equation (11). can do.

  2, 3, and 4, HARQ-ACK (orthogonal DPDCH is an interference signal) using the SIR measurement apparatus 100 according to the present embodiment and the SIR measurement apparatus 10 according to the related art. Simulation of RSCP, ISCP, and SIR of RSCP, ISCP, and SIR for pilot signal (in-phase component that is orthogonal is not an interference signal) using SIR measurement apparatus 10 according to the prior art And the results calculated in. 2, 3, and 4, “Δ” indicates a simulation result of HARQ-ACK using the SIR measuring apparatus 100 according to the present embodiment, and “□” indicates the SIR measuring apparatus 10 according to the related art. A simulation result for the used pilot signal and “x” indicate a simulation result for HARQ-ACK using the SIR measuring apparatus 10 according to the related art. 2, 3, and 4, the horizontal axis thereof represents the SIR [dB] of the input signal, that is, the HARQ-ACK or the pilot signal, and the vertical axis thereof represents the measurement SIR [ dB].

  As can be seen from FIG. 2, the SIR measurement apparatus 100 according to the present embodiment can calculate SIR almost as expected in SIR measurement for HARQ-ACK in which orthogonal DPDCH is an interference signal. I understand. 2 that the SIR measuring apparatus 100 according to the present embodiment can measure the HAIR-ACK SIR more accurately than the SIR measuring apparatus 10 according to the prior art.

  Therefore, according to SIR measuring apparatus 100 according to the present embodiment, the RSCP and ISCP are calculated using only the orthogonal components of the received signal after RAKE combining, and therefore simple signal processing is only performed on the orthogonal components. Thus, the SIR of the received signal can be accurately measured.

  Further, according to the SIR measuring apparatus 100, the ISCP ′ is calculated by the interference signal power calculation unit 104 by the equation (10), and the calculated ISCP ′ is accurately corrected only by being doubled by the interference signal power correction unit 105. Since the correct ISCP is calculated, the accuracy of the SIR can be further improved by simply performing simple signal processing on the orthogonal component of the received signal after RAKE combining.

  In addition, according to a wireless communication device such as a base station device provided with the SIR measurement device 100, since the signal processing of the received signal in the SIR measurement device 100 is simple, the response speed and power consumption can be improved. .

  Further, according to the base station apparatus provided with the SIR measuring apparatus 100, the RSCP and ISCP are calculated based on the orthogonal components of the received signal after RAKE combining, so that it can be used for W-CDMA wireless communication. it can.

  Moreover, according to the base station apparatus provided with the SIR measuring apparatus 100, since the SIR calculated by the SIR measuring apparatus 100 is used for decoding HARQ-ACK, the decoding performance can be improved.

  Note that the SIR measuring apparatus 100 according to the present embodiment and the wireless communication apparatus including the SIR measuring apparatus 100 may be applied or modified as follows.

  In the present embodiment, the case where the wireless communication apparatus includes one SIR measurement apparatus 100 and only the orthogonal component of the received signal after RAKE combining is input to the SIR measurement apparatus 100 has been described. For example, the wireless communication device includes two SIR measuring devices 100, and each SIR measuring device 100 individually measures the SIR for the in-phase component and the quadrature component of the received signal after RAKE combining. You may make it do. In addition, for example, the wireless communication apparatus includes one SIR measuring apparatus 100, and the SIR measuring apparatus 100 alternately measures SIR in time division with respect to the in-phase component and the quadrature component of the received signal after RAKE combining. May be.

  In the present embodiment, the case where interference signal power correction section 105 corrects ISCP ′ input from interference signal power calculation section 104 by a factor of two has been described, but the present invention is limited to this case. Instead, for example, the interference signal power correcting unit 105 is removed from the SIR measuring apparatus 100, and a component arranged downstream of the SIR calculating unit 106 uses the half value of the SIR output from the SIR calculating unit 106 as an accurate SIR. You may make it do.

  The desired signal-to-interference signal power ratio measuring apparatus, radio communication apparatus, and base station apparatus according to the present invention can accurately calculate the SIR through simple signal processing even when the in-phase component and the quadrature component of the received signal interfere with each other. It has the effect that it can be measured, and is useful for a wireless communication system, particularly a wireless communication system using the W-CDMA system.

The block diagram which shows the structure of the SIR measuring apparatus based on this invention The figure which shows the simulation result of the SIR measurement by the SIR measuring apparatus which concerns on this invention The figure which shows the simulation result of the SIR measurement by the SIR measuring apparatus which concerns on this invention The figure which shows the simulation result of the SIR measurement by the SIR measuring apparatus which concerns on this invention The block diagram which shows the structure of the SIR measuring apparatus based on a prior art

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Desired signal to interference signal power ratio (SIR) measurement apparatus 101 Known pattern generation part 102 Average symbol calculation part 103 Desired signal power calculation part 104 Interference signal power calculation part 105 Interference signal power correction part 106 SIR calculation part

Claims (5)

Desired signal power calculating means for calculating the power of the desired signal included in the received signal based on either the in-phase component or the quadrature component of the received signal after RAKE combining;
Interference signal power calculating means for calculating power of an interference signal included in the received signal based on either the in-phase component or the quadrature component of the received signal after RAKE combining;
Desired signal-to-interference signal power ratio calculating means for calculating a ratio using the calculated desired signal power as a numerator and the calculated interference signal power as a denominator. Ratio measuring device.   The interference signal power calculation unit corrects the dispersion value of the power of the interference signal included in the reception signal by a factor of two based on either the in-phase component or the quadrature component of the reception signal after RAKE combining. The desired signal-to-interference signal power ratio measuring apparatus according to claim 1, wherein the interference signal power is calculated by:   A wireless communication apparatus comprising the desired signal to interference signal power ratio measuring apparatus according to claim 1. A base station apparatus that is a wireless communication apparatus according to claim 3,
The desired signal power calculating means calculates the power of the desired signal included in the received signal of HS-DPCCH after RAKE combining,
The base station apparatus, wherein the interference signal power calculation means calculates the power of the interference signal included in the received signal of HS-DPCCH after RAKE combining.   5. The base station apparatus according to claim 4, wherein the desired signal-to-interference signal power ratio calculated by the desired signal-to-interference signal power ratio calculating unit is used for HARQ-ACK decoding.

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