JP2006013915A - Radio receiving device and radio receiving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio receiving device and a radio receiving method which are possible to detect the appropriate receiving power of a desired wave at the time of transmission diversity operation which performs communication using a plurality of transmission antennas. <P>SOLUTION: An averaging part 3b calculates a symbol mean value regarding to signals of respective antennas (Ant#1, Ant#2) from a sending side, and outputs it to an RSCP (Received Signal Code Power) calculator 6. The RSCP calculator 6 has a 1st RSCP calculator which adds and the squares symbol mean values of the respective antennas, and a 2nd RSCP calculator which squares and adds the symbol mean values of the respective antennas, and outputs either of the outputs of the 1st RSCP calculator and the 2nd RSCP calculator as the receiving power of a desired wave. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a radio reception apparatus and a radio reception method, and more particularly to a radio reception apparatus and a radio reception method used for code division multiple access (CDMA) communication.

As a conventional wireless receiver, there has been a mobile communication system receiver including a reception level measurement circuit (for example, see Patent Document 1). Such a reception level measurement circuit detects a received signal strength indication (RSSI) input to the receiver, and further extracts a desired wave component and an interference wave component from the received signal. Accurate reception level measurement is performed by detecting component power and interference wave component power.
Japanese Patent No. 3474826

  By the way, during the operation of transmission diversity in which signals are transmitted to the receiving side such as a wireless communication terminal using a plurality of transmitting antennas on the transmitting side such as a base station apparatus, the phase difference between signals transmitted by the plurality of transmitting antennas In some cases, the reception level measurement on the reception side for transmission power control on the transmission side cannot be appropriately performed.

  The present invention has been made in view of the above-described conventional circumstances, and is a radio reception apparatus and radio reception method capable of detecting a desired wave reception power suitable for transmission diversity operation in which communication is performed using a plurality of transmission antennas. The purpose is to provide.

  The radio reception apparatus according to the present invention calculates an average value calculating unit that calculates a symbol average value of a signal from each of the antennas with respect to a signal transmitted from a transmitting side using a plurality of antennas, and the average value calculating unit. A first desired wave received power calculating means for adding the average symbol values of the respective antennas and squaring the added symbol average value; and square the symbol average values of the respective antennas calculated by the average value calculating means. Desired output value of any one of the second desired wave received power calculating means for adding the squared symbol average value, and the first desired wave received power calculating means and the second desired wave received power calculating means Desired wave received power output means for outputting as wave received power.

  With this configuration, it is possible to detect the desired signal reception power at the time of transmission diversity operation in which communication is performed using a plurality of transmission antennas.

  The desired wave received power output means includes a phase difference detection means for detecting a phase difference based on a symbol average value of a received signal from each antenna, and when the phase difference is smaller than a predetermined value, An output of a first desired wave received power calculating means; and a selecting means for selecting an output of the second desired wave received power calculating means when the phase difference is equal to or greater than the predetermined value.

  With this configuration, it is possible to detect the desired wave received power according to the phase difference between the received signals from the antennas.

  The desired wave received power means inputs the symbol average value to the first desired wave received power calculating means when the phase difference is smaller than the predetermined value, and the phase difference is greater than or equal to the predetermined value. In this case, it further includes symbol average value input means for input to the second desired wave received power calculation means.

  With this configuration, only the selected desired wave received power calculating means performs the arithmetic processing, so that the load associated with the arithmetic processing can be reduced.

  Further, the desired wave received power output means compares the output of the first desired wave received power calculation means with the output of the second desired wave received power calculation means, and obtains a difference between them. If the difference between the output of the first desired wave received power calculating means and the output of the second desired wave received power calculating means is equal to or greater than a predetermined value, the output of the first desired wave received power calculating means is Selecting means for selecting an output of the second desired wave received power calculating means when the difference is smaller than the predetermined value.

  With this configuration, it is possible to detect the desired wave received power according to the phase difference between the received signals from the respective antennas.

  The present invention provides a desired wave received power detection program for causing a computer to function as each of the above-described means. With this program, it is possible to detect the desired signal reception power at the time of transmission diversity operation in which communication is performed using a plurality of transmission antennas.

  The radio reception method of the present invention includes a step of calculating a symbol average value of a signal from each of the antennas for a signal transmitted from a transmission side using a plurality of antennas, and the calculated symbol average for each antenna. A step of calculating a first desired wave received power that squares the added symbol average value, squares the calculated symbol average value for each antenna, and adds the squared symbol average value Performing a second desired wave received power calculation; outputting a calculated value of any one of the first desired wave received power calculation and the second desired wave received power calculation as a desired wave received power; Have

  By this method, it is possible to detect the desired wave reception power appropriate during the transmission diversity operation in which communication is performed using a plurality of transmission antennas.

  ADVANTAGE OF THE INVENTION According to this invention, the radio | wireless receiving apparatus and radio | wireless receiving method which can detect the desired wave receiving power suitable at the time of the transmission diversity operation | movement which communicates using a some transmitting antenna can be provided.

  Before describing an embodiment of the present invention, transmission diversity and measurement of desired wave received power during transmission diversity operation will be considered. Here, as an example of transmission diversity, a closed loop mode 1 standardized by 3GPP (3rd Generation Partnership Project) will be described as an example.

  In the closed loop mode 1, the base station transmits a pilot signal of another pattern and a data signal of the same pattern from two antennas (Ant # 1 and Ant # 2) to the radio communication terminal. The pilot signal is transmitted on a dedicated physical control channel (DPCCH) that is an information channel for controlling a dedicated physical channel (DPCH).

  The wireless communication terminal performs phase estimation for each of the signals received from the two antennas of the base station, and transmits feedback information FBI (Feedback indicator), which is a control signal that reduces the phase difference, to the base station. The base station rotates the phase of the transmission signal of one antenna (Ant # 2) based on the feedback information FBI received from the wireless communication terminal. Thereby, in the radio communication terminal, fading can be reduced and reception performance can be improved.

  In the closed loop mode 1, as shown in FIG. 5A, a combined vector signal is received from two antennas (Ant # 1 and Ant # 2) of the base station. Therefore, the symbol average values of the DPCCH pilot signals (DPCCH-Pilot-Ant # 1, DPCCH-Pilot-Ant # 2) from the respective antennas (Ant # 1, Ant # 2) are added in phase, and the resultant vector By detecting the power value as the desired signal received power (RSCP: Received Signal Code Power), the detected value is close to the quality of the actual received signal, so it is effective to use this value for downlink transmission power control. Is.

  However, in this method, when the diversity feedback is not accurately performed for some reason and the phase difference between the two antennas becomes large as shown in FIG. 5B, the power of the combined vector as described above. When the value is detected, both vectors cancel each other, and the desired wave reception power is measured to be small at the wireless communication terminal even though the base station transmits with sufficient transmission power. As a result, the desired wave-to-interference wave power ratio is lowered, and the base station may be controlled to increase the transmission power. However, in the state of FIG. 5B, each antenna is received with sufficient quality, and if the feedback of transmission diversity is accurately reflected, sufficient reception quality can be obtained, so there is no need to increase the transmission power. There are many cases.

  Therefore, in the embodiment of the present invention, the first desired wave received power calculated by adding the symbol average value for each antenna and then squaring, and the symbol average value for each antenna are squared and added. By detecting the output value of any one of the calculated second desired wave received powers as the desired wave received power, it is possible to detect an appropriate desired wave received power even during the transmission diversity operation.

(First embodiment)
FIG. 1 is a schematic configuration diagram illustrating a wireless reception device according to a first embodiment of the present invention. As shown in FIG. 1, the radio reception apparatus according to the embodiment of the present invention includes an A / D conversion unit 1, a plurality (n) of fingers F1 to Fn, a RAKE combining unit 8, a channel decoder unit 9, An ISCP combining unit 10, an RSCP combining unit 11, and an SIR calculating unit 12 are provided. Each of the fingers F1 to Fn includes despreading units 2a and 2b, averaging units 3a and 3b, a phase estimation unit 4, a synchronous detection unit 5, an RSCP calculation unit 6, and an ISCP calculation unit 7.

  Of the above-described configurations, at least the averaging units 3a and 3b and the RSCP calculation unit 6 may be mainly configured by a processor that operates according to a desired wave received power calculation program.

  The A / D converter 1 A / D converts the baseband analog signal and outputs a digital signal. The despreading units 2a and 2b perform despreading of a received signal using a common pilot channel (CPICH) and DPCH, respectively, and output a despread value.

  The averaging units 3a and 3b calculate and output symbol average values of the despread values of the pilot portions while multiplying the complex conjugates of the CPICH and DPCH pilot patterns output from the despreading units 2a and 2b, respectively.

  The phase estimation unit 4 obtains a phase estimation value based on the outputs of the averaging units 3a and 3b. The synchronous detection unit 5 calculates the complex conjugate value of the phase estimation value output from the phase estimation unit 4, and performs synchronous detection by multiplying the despread value output from the despreading unit 2b by this complex conjugate number. .

  The RSCP calculator 6 calculates the symbol average value of both antennas (Ant # 1, Ant # 2) of the dedicated physical control channel (DPCCH), which is the DPCH control signal channel, output from the averaging unit 3b. Calculate the desired wave received power.

  The ISCP calculation unit 7 obtains CPICH dispersion from the outputs of the despreading unit 2a and the averaging unit 3a, and outputs the obtained dispersion as interference wave received power (ISCP). Note that the ISCP calculation unit may obtain the dispersion of DPCH from the outputs of the despreading unit 2b and the averaging unit 3b, and output it as ISCP.

  The RAKE combining unit 8 combines the synchronous detection signals output from the synchronous detection units 5 of the fingers F1 to Fn. The channel decoder unit 9 performs processing such as deinterleaving and error correction on the post-RAKE combining signal output from the RAKE combining unit 8.

  The ISCP combiner 10 combines the interference wave power output from the ISCP calculator 7 of each finger F1 to Fn. The RSCP combiner 11 combines the desired wave received power output from the RSCP calculator 6 of each finger. The SIR calculation unit 12 calculates a ratio between the desired wave reception power and the interference wave reception power, and outputs a desired signal to interference signal ratio (SIR).

  FIG. 2 is a diagram illustrating an example of a schematic configuration of the RSCP calculation unit according to the first embodiment. As illustrated in FIG. 2, the RSCP calculation unit 6 a includes a first RSCP calculation unit 61, a second RSCP calculation unit 62, an angle difference detection unit 63, and a selection unit 64.

  The first RSCP calculation unit 61 receives the symbol average value regarding each antenna (Ant # 1 and Ant # 2) output from the averaging unit 3b and adds them, and squares the output of the addition unit 611. And a square part 612.

  The second RSCP calculation unit 62 squares the symbol average values related to the antennas (Ant # 1, Ant # 2) output from the averaging unit 3b, and outputs the squares 621 and 622 and the squares 621 and 622, respectively. And an adder 623 for adding.

  The angle difference detector 63 calculates the phase difference of the symbol average value for each antenna and outputs a control signal to the selector 64. Based on the control signal output from the angle difference detection unit 63, the selection unit 64 outputs the output of the first RSCP calculation unit 61 when the inter-antenna phase difference detected by the angle difference detection unit 63 is smaller than the threshold. If the inter-antenna phase difference is equal to or greater than the threshold, the output of the second RSCP calculator 62 is selected and output as the desired wave received power.

  Thus, for example, as shown in FIG. 5A, when the phase difference between the signals from the antennas (Ant # 1, Ant # 2) is small, the signals from the antennas are added (synthesized). By selecting the output of the first RSCP calculator 61 that obtains the desired received power by squaring, a value close to the quality of the actual received signal can be detected.

  On the other hand, as shown in FIG. 5B, when the phase difference between the signals from the antennas (Ant # 1 and Ant # 2) is large, the signals from the antennas are squared respectively. By selecting the output of the second RSCP calculation unit 62 that adds after obtaining the received power, the desired wave received power reflecting the transmission power of each antenna can be detected even when the phase difference is large. .

  With this configuration, since either one of the first RSCP calculation unit and the second RSCP calculation unit is selected according to the phase difference between signals from each transmission antenna and output as the desired wave received power, It is possible to detect the desired received signal power at the time of transmission diversity operation.

  FIG. 3 is a diagram illustrating another example of the schematic configuration of the RSCP calculation unit of the first embodiment. In FIG. 3, the same reference numerals are given to portions overlapping with FIG. 2. The RSCP calculation unit 6b in this example calculates the symbol average value of each antenna (Ant # 1, Ant # 2) based on the control signal output from the angle difference detection unit 63, and the first RSCP calculation unit 61 and the first RSCP calculation unit 61b. The selectors 65 a and 65 b are input to any one of the two RSCP calculators 62.

  The selectors 65a and 65b calculate the first RSCP calculation unit 61 when the inter-antenna phase difference detected by the angle difference detection unit 63 is smaller than the threshold, and perform the second RSCP calculation when the inter-antenna phase difference is equal to or larger than the threshold. The unit 62 inputs the symbol average value of each antenna.

  With this configuration, it is only necessary to operate one of the first RSCP calculator and the second RSCP calculator that employs the output as the desired received power, so that the calculation load in the RSCP calculator can be reduced.

According to the radio reception apparatus and radio reception method of the first embodiment of the present invention, the method of calculating the desired wave received power is switched depending on the phase difference between signals from a plurality of transmission antennas for transmission diversity. Thus, it is possible to improve downlink transmission power control performance and perform appropriate transmission power control regardless of any phase difference between antennas.
(Second Embodiment)

  Next, a radio reception apparatus and radio reception method according to the second embodiment of the present invention will be described. The radio reception apparatus according to the present embodiment is substantially the same as the configuration of the radio reception apparatus according to the first embodiment described with reference to FIG. 1, but the configuration of the RSCP calculation unit 6 is different.

  FIG. 4 is a diagram illustrating a schematic configuration of an RSCP measurement unit according to the second embodiment of this invention. Parts that are the same as those in FIG. 2 described in the first embodiment are denoted by the same reference numerals.

  As shown in FIG. 4, the RSCP calculation unit 6c of the present embodiment compares the outputs of the first RSCP calculation unit 61 and the second RSCP calculation unit 62 to calculate the difference (the output of the first RSCP calculation unit). Value—the output value of the second RSCP calculation unit), and a comparison unit 66 that outputs a control signal to the selection unit 64 according to the difference.

  When the difference between the outputs of the first and second RSCP calculation units 61 and 62 obtained by the comparison unit 66 is equal to or greater than a predetermined threshold value, the selection unit 64 determines whether the first RSCP calculation unit 61 If it is smaller than the threshold value, the output of the second RSCP calculator 62 is selected.

  The first RSCP calculator 61 adds (synthesizes) the signals from the antennas and then squares them to calculate the desired received power, so as shown in FIGS. 5 (A) and 5 (B). In addition, the calculated value (output value) of the first RSCP calculating unit 61 becomes smaller as the phase difference between the signals from the antennas becomes larger. On the other hand, the output of the second RSCP calculator 62 does not depend on the phase difference between the signals from the respective antennas. That is, as the phase difference between the signals from the antennas increases, the above-described difference value decreases.

  Thus, when the above-described difference is equal to or larger than a predetermined threshold value, for example, as shown in FIG. 5A, if the phase difference of the signals from the antennas (Ant # 1, Ant # 2) is small By determining and selecting the output of the first RSCP calculator, a value close to the quality of the actual received signal can be detected.

  Accordingly, when the above-described difference is smaller than the predetermined threshold value, it is determined that the phase difference between the signals from the respective antennas (Ant # 1, Ant # 2) is large as shown in FIG. 5B. Then, by selecting the output of the second RSCP calculator, it is possible to detect the desired wave received power reflecting the transmission power of each antenna even when the phase difference is large.

  According to the radio reception apparatus and radio reception method of the second embodiment of the present invention, the calculation method of the desired wave reception power is switched according to the difference between the calculation values, so that the downlink transmission power control performance is improved. The transmission power can be appropriately controlled regardless of the phase difference between the antennas.

  In the first and second embodiments described above, closed loop mode 1 is shown as an example of transmission diversity. However, the present invention is not limited to this, and is generally applied to transmission diversity for controlling the phases of a plurality of antennas. And similar effects can be obtained.

  INDUSTRIAL APPLICABILITY The radio reception apparatus and radio reception method of the present invention have an effect of enabling detection of appropriate desired wave reception power during transmission diversity operation in which communication is performed using a plurality of transmission antennas, and are useful for portable terminal devices and the like. .

1 is a schematic configuration diagram showing a wireless reception device according to a first embodiment of the present invention. The figure which shows an example of schematic structure of the RSCP calculation part of 1st Embodiment The figure which shows the other example of schematic structure of the RSCP calculation part of 1st Embodiment. The figure which shows schematic structure of the RSCP measurement part of the 2nd Embodiment of this invention. The figure which shows a synthetic vector when the phase difference for every antenna changes

Explanation of symbols

1 A / D conversion unit 2a, 2b Despreading unit 3a, 3b Average unit 4 Phase estimation unit 5 Synchronous detection unit 6, 6a, 6b, 6c RSCP calculation unit 7 ISCP calculation unit 8 RAKE combining unit 9 Channel decoder unit 10 ISCP combining Unit 11 RSCP combining unit 12 SIR calculating unit 61 first RSCP calculating unit 62 second RSCP calculating unit 63 angle difference detecting unit 64, 65a, 65b selecting unit 66 comparing unit 611, 623 adding unit 612, 621, 622 square unit

Claims (6)

With respect to signals transmitted from the transmitting side using a plurality of antennas, average value calculating means for calculating symbol average values of signals from the respective antennas;
First desired wave received power calculating means for adding the symbol average values of the antennas calculated by the average value calculating means and squaring the added symbol average values;
A second desired wave received power calculating unit that squares the symbol average value of each antenna calculated by the average value calculating unit and adds the squared symbol average value;
Desired wave received power output means for outputting an output value of any one of the first desired wave received power calculating means and the second desired wave received power calculating means as desired wave received power;
A wireless receiver comprising: The wireless receiver according to claim 1,
The desired wave received power output means includes:
Phase difference detection means for detecting the phase difference based on the symbol average value of the received signal from each antenna;
When the phase difference is smaller than a predetermined value, the output of the first desired wave received power calculating means is output. When the phase difference is greater than the predetermined value, the output of the second desired wave received power calculating means is output. A selection means to select;
A wireless receiver. The wireless receiver according to claim 2,
The desired wave received power means inputs the symbol average value to the first desired wave received power calculating means when the phase difference is smaller than the predetermined value, and when the phase difference is greater than or equal to the predetermined value. Is a radio receiver further comprising symbol average value input means for inputting to the second desired wave received power calculating means. The wireless receiver according to claim 1,
The desired wave received power output means includes:
Comparing means for comparing the output of the first desired wave received power calculating means and the output of the second desired wave received power calculating means to obtain a difference between them;
When the difference between the output of the first desired wave received power calculating means and the output of the second desired wave received power calculating means is a predetermined value or more, the output of the first desired wave received power calculating means is Selecting means for selecting an output of the second desired wave received power calculating means when the difference is smaller than the predetermined value;
A wireless receiver.   5. A desired wave received power detection program for causing a computer to function as each means according to claim 1. Calculating a symbol average value of signals from each of the antennas with respect to signals transmitted from the transmitting side using a plurality of antennas;
Adding a calculated symbol average value for each antenna, and performing a first desired wave received power calculation of squaring the added symbol average value;
Performing a second desired wave received power calculation by squaring the calculated symbol average value for each antenna and adding the squared symbol average value;
Outputting one of the calculated values of the first desired wave received power and the second desired wave received power as desired wave received power;
A wireless reception method.

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