Radio receiving device

Abstract

To adjust power by detecting decrease in a signal level due to sampling rate conversion at a stage where a sampling rate is high.SOLUTION: A first power ratio measurement unit (6a) measures a ratio of power of a digital reception signal before rate conversion to target power, a second power ratio measurement unit (6b) measures a ratio of power of the digital reception signal after rate conversion to the target power, and a third power ratio measurement unit (6c) measures a ratio of power of the digital reception signal after waveform shaping to the target power. A first power adjustment unit (variable attenuator of an analog reception unit) adjusts the power of the analog reception signal before A / D conversion, a second power adjustment unit (3a) adjusts the power of the digital reception signal before rate conversion, and a third power adjustment unit (3b) adjusts the power of the digital reception signal after rate conversion. A gain setting unit (8) determines gains to be set in the first to third power adjustment units so that the ratios measured by the respective first to third power ratio measurement units become 1.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a receiving device in wireless communication involving movement, and more particularly to automatic gain control that compensates for fluctuations in reception level caused by movement. [Background technology]

[0002] In wireless communication involving movement, when a mobile station moves from directly under a base station to the cell boundary, the received signal power of the mobile station fluctuates greatly. In the receiving device of the mobile station, when the received signal power is large, saturation occurs inside the receiving device, and when the received signal power is small, the received signal power required for demodulation processing cannot be satisfied, resulting in degradation of receiving performance. To address this problem, the receiving device of the mobile station has an automatic gain control function that adjusts the received signal power before demodulation processing so that saturation does not occur inside the receiving device and the received signal power required for demodulation processing is secured.

[0003] Gain control by automatic gain control is performed by measuring the power of the received signal and controlling the gain of a variable attenuator or amplifier. However, when a high-power interfering signal is present in addition to the desired signal in the received signal, gain control is performed on the power of the interfering signal, which can reduce the power of the desired signal.

[0004] One automatic gain control function that addresses this problem is to amplify the power of a desired signal when the power of the desired signal becomes smaller due to automatic gain control performed on a wideband signal in the analog signal processing unit by performing automatic gain control on a narrowband signal obtained by extracting the desired signal using a digital filter in the digital signal processing unit (for example, see Patent Document 1 below). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3086060 Summary of the Invention [Problem to be solved by the invention]

[0006] In the automatic gain control of Patent Document 1, gain adjustment is performed using a narrowband signal obtained by extracting the desired signal using digital signal processing. This means that the power of the desired signal is easily affected by quantization noise, which may result in degradation of reception performance.

[0007] Quantization noise occurs in digital signal processing, and if its effect on reception processing is significant, reception performance will deteriorate. The smaller the signal amplitude, the greater the effect of quantization noise, but if the sampling frequency (sampling rate) is high relative to the bandwidth of the desired signal, the effect of quantization noise on the desired signal can be reduced. Therefore, if it is necessary to amplify the signal amplitude in signal processing that reduces the sampling frequency, it is better to amplify at a sampling frequency stage as high as possible in order to reduce the effect of quantization noise.

[0008] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a wireless receiving device that is capable of detecting a decrease in signal level due to sampling rate conversion at a stage where the sampling frequency is high, and adjusting power. [Means for solving the problem]

[0009] A wireless receiving device according to the present disclosure includes an A / D conversion unit that performs A / D conversion to convert an analog received signal into a digital received signal, a rate conversion filter that performs rate conversion to convert a sampling rate of the digital received signal into a sampling rate required for demodulation processing, a waveform shaping filter that performs waveform shaping of the digital received signal after the rate conversion, a first power ratio measurement unit that measures a ratio of the power of the digital received signal before the rate conversion to a target power, a second power ratio measurement unit that measures a ratio of the power of the digital received signal after the rate conversion and before the waveform shaping to a target power, and the first power adjustment unit adjusting the power of the analog received signal before the A / D conversion; a second power adjustment unit adjusting the power of the digital received signal before the rate conversion; a third power adjustment unit adjusting the power of the digital received signal after the rate conversion and before the waveform shaping; and a gain setting unit determining gains to be set in the first power adjustment unit, the second power adjustment unit, and the third power adjustment unit based on the ratios measured by the first power ratio measurement unit, the second power ratio measurement unit, and the third power ratio measurement unit so that the ratio becomes 1. Effect of the Invention

[0010] According to the wireless receiving device according to the present disclosure, a decrease in signal level due to conversion of the sampling rate can be detected at a stage where the sampling frequency is high, and power can be adjusted accordingly, thereby suppressing the effects of quantization noise. [Brief description of the drawings]

[0011] [Figure 1] 1 is a configuration diagram of a wireless communication system including a wireless receiving device according to a first embodiment. [Diagram 2] 1 is a configuration diagram of a wireless receiving device according to a first embodiment. [Diagram 3] 2 is a block diagram of a first digital receiving section of the wireless receiving device according to the first embodiment. FIG. [Figure 4]4 is a diagram illustrating frequency components of an input signal to a rate conversion filter of the wireless receiving device according to the first embodiment. FIG. [Diagram 5] 4 is a diagram illustrating frequency components of an output signal of a rate conversion filter of the wireless receiving device according to the first embodiment. [Figure 6] 4 is a diagram illustrating output timing of a trigger signal generated by a trigger generating unit of the wireless receiving device according to the first embodiment. [Figure 7] FIG. 11 is a block diagram of a first digital receiving section of a wireless receiving device according to a second embodiment. [Figure 8] 13 is a diagram illustrating output timing of a trigger signal generated by a trigger generating unit of a wireless receiving device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] <Embodiment 1> Fig. 1 is a configuration diagram of a wireless communication system including a wireless receiving device according to a first embodiment. The wireless communication system in Fig. 1 includes a base station 100, a mobile station 101, and a control station 102. Fig. 1 shows a communication area 103 of the base station 100. The wireless receiving device according to the first embodiment constitutes a part of the mobile station 101. However, application of the wireless receiving device according to the first embodiment is not limited to the wireless communication system having the configuration shown in Fig. 1.

[0013] The operation of the wireless communication system in Fig. 1 will be described. In accordance with instructions from a control station 102, a base station 100 performs processing such as modulation on information to be transmitted to a mobile station 101, converts the information into a wireless signal, and transmits it. While moving within a communication area 103, the mobile station 101 receives the wireless signal transmitted by the base station 100. A wireless receiving device of the mobile station 101 performs processing such as demodulation on the received wireless signal, and extracts the information transmitted by the base station 100 from the received wireless signal.

[0014] Fig. 2 is a configuration diagram of radio receiving device 200 according to the first embodiment provided in mobile station 101. Radio receiving device 200 in Fig. 2 includes antenna 201, analog receiving unit 202, and digital receiving unit 203. Digital receiving unit 203 includes first digital receiving unit 204 and second digital receiving unit 205.

[0015] The operation of the mobile station 101 in FIG. 2 will now be described.

[0016] The antenna 201 receives a radio signal transmitted by the base station 100 and inputs it to the analog receiving unit 202 .

[0017] The analog receiving unit 202 converts the received radio frequency signal into an intermediate frequency signal and outputs it. The analog receiving unit 202 includes a variable attenuator and an amplifier that adjust the power of the received signal according to the gain input from the digital receiving unit 203. This variable attenuator and amplifier function as a first power adjustment unit that adjusts the power of the received signal before A / D conversion (analog / digital conversion). Here, it is assumed that the analog receiving unit 202 includes a variable attenuator. Hereinafter, the intermediate frequency signal output by the analog receiving unit 202 is referred to as the "analog received signal".

[0018] The digital receiving unit 203 converts the analog received signal output by the analog receiving unit 202 into a digital signal, and extracts information contained in the received signal by digital signal processing. Specifically, the following processing is performed by the first digital receiving unit 204 and the second digital receiving unit 205. Hereinafter, the signal obtained by converting the analog received signal into a digital signal is referred to as the "digital received signal."

[0019] The first digital receiving unit 204 of the digital receiving unit 203 converts the analog received signal output by the analog receiving unit 202 into a digital received signal, and then performs frequency conversion by digital signal processing to convert the signal into a digital received signal as a baseband complex signal, and also performs sampling rate conversion to convert the sampling rate of the baseband complex signal into a sampling rate sufficient for demodulating the desired signal. Furthermore, the first digital receiving unit 204 adjusts the power of the baseband complex signal so that the power becomes appropriate for demodulating the desired signal.

[0020] The second digital receiving unit 205 performs reception processing such as extraction of the Nyquist point and frame timing, demodulation, and error correction on the baseband complex signal output by the first digital receiving unit 204, and extracts information.

[0021] The technology according to the present disclosure relates particularly to the processing performed by the first digital receiving unit 204, and does not impose any restrictions on other processing.

[0022] FIG. 3 is a block diagram of first digital receiving section 204 of the wireless receiving device according to the first embodiment.

[0023] The first digital receiving unit 204 in FIG. 3 includes an A / D conversion unit 1, a quadrature detection unit 2, power adjustment units 3a and 3b, a rate conversion filter 4, a waveform shaping filter 5, power ratio measurement units 6a to 6c, correction value calculation units 7a and 7b, a gain setting unit 8, and a trigger generation unit 9.

[0024] The A / D converter 1 performs A / D conversion to convert an analog received signal output by the analog receiver 202 into a digital received signal. The quadrature detector 2 converts the digital received signal output by the A / D converter 1 into a digital signal as a baseband complex signal. The power adjuster 3a adjusts the power of the baseband complex signal output by the quadrature detector 2. This power adjuster 3a is a second power adjuster that adjusts the power of the digital received signal (baseband complex signal) before rate conversion. The rate conversion filter 4 performs rate conversion to convert the sampling rate of the baseband complex signal output by the power adjuster 3a. The power adjuster 3b adjusts the power of the baseband complex signal output by the rate conversion filter 4. This power adjuster 3b is a third power adjuster that adjusts the power of the digital received signal after rate conversion and before waveform shaping. The waveform shaping filter 5 performs waveform shaping of the baseband complex signal output by the power adjuster 3b.

[0025] The power ratio measurement unit 6a measures the ratio of the power of the baseband complex signal output from the quadrature detection unit 2 to a target power. This power ratio measurement unit 6a is a first power ratio measurement unit that measures the ratio of the power of the digital reception signal before rate conversion to a target power. The power ratio measurement unit 6b measures the ratio of the power of the baseband complex signal output from the rate conversion filter 4 to a target power. This power ratio measurement unit 6b is a second power ratio measurement unit that measures the ratio of the power of the digital reception signal after rate conversion and before waveform shaping to a target power. The power ratio measurement unit 6c measures the ratio of the power of the baseband complex signal output from the waveform shaping filter 5 to a target power. This power ratio measurement unit 6c is a third power ratio measurement unit that measures the ratio of the power of the digital reception signal after waveform shaping to a target power.

[0026] The correction value calculation unit 7a calculates a correction value for the gain setting value to be set in the power adjustment unit 3a from the power ratios output by the power ratio measurement units 6a and 6b, respectively. The correction value calculation unit 7b calculates a correction value for the gain setting value to be set in the power adjustment unit 3b from the power ratios output by the power ratio measurement units 6b and 6c, respectively.

[0027] The gain setting unit 8 calculates and outputs the gain setting value of the variable attenuator of the analog receiving unit 202, the gain setting value of the power adjustment unit 3a, and the gain setting value of the power adjustment unit 3b from the power ratio output by the power ratio measurement unit 6a, the correction value output by the correction value calculation unit 7a, and the correction value output by the correction value calculation unit 7b. At this time, the gain setting unit 8 calculates the gain setting value of each of the variable attenuator of the analog receiving unit 202, the power adjustment unit 3a, and the power adjustment unit 3b so that the power ratios measured by the power ratio measurement unit 6a and the power ratio measurement unit 6b are 1, respectively. That is, the gain setting unit 8 determines the gains to be set in the first power adjustment unit, the second power adjustment unit, and the third power adjustment unit based on the measurement results by the first power ratio measurement unit, the second power ratio measurement unit, and the third power ratio measurement unit so that the power of the digital reception signal before rate conversion, the power of the digital reception signal after rate conversion and before waveform shaping, and the power of the digital reception signal after waveform shaping are each a target power.

[0028] The trigger generating section 9 outputs a trigger that defines the reference timing for operation of each of the power ratio measuring sections 6a, 6b, 6c and the gain setting section 8.

[0029] The operation of the first digital receiving section 204 in FIG. 3 will be described.

[0030] The intermediate frequency analog received signal output by the analog receiving unit 202 is input to the A / D conversion unit 1. The A / D conversion unit 1 converts the input intermediate frequency analog received signal into an intermediate frequency digital received signal. The process performed by the A / D conversion unit 1 may be a general A / D conversion process, and therefore a detailed description thereof will be omitted.

[0031] The digital received signal output by the A / D conversion unit 1 is input to the quadrature detection unit 2. The quadrature detection unit 2 converts the frequency of the intermediate frequency digital received signal to baseband, and also converts the digital received signal into a baseband complex signal by converting it into a signal in a rectangular coordinate system. These conversion processes are also general processes, so a detailed description will be omitted. Furthermore, the signal in the rectangular coordinate system is expressed as a complex signal with the in-phase component as the real part and the quadrature component as the imaginary part.

[0032] The baseband complex signal output by the quadrature detector 2 is input to the power adjustment unit 3a. The power adjustment unit 3a multiplies the baseband complex signal by a gain G1 [dB] output by the gain setting unit 8 and outputs the result. The in-phase component of the baseband complex signal input to the power adjustment unit 3a is ich , the orthogonal components are si qch The in-phase component of the baseband complex signal output from the power adjustment unit 3a is so ich , the orthogonal components are qch Then, the in-phase component so of the baseband complex signal output from the power adjustment unit 3a is ich and the quadrature component so qch is expressed by the following equation (1).

[0033]

number

[0034] The baseband complex signal output by the power adjustment unit 3a is input to the rate conversion filter 4. The rate conversion filter 4 down-samples the sampling rate of the A / D conversion unit 1 to a sampling rate that is, for example, four times the symbol rate.

[0035] Since the downsampling process can be a general one, a detailed description of the process will be omitted, but the effect of this process on the signal power will be explained. Figures 4 and 5 show images of the frequency components of the input signal and output signal of the rate conversion filter 4.

[0036] FIG. 4 shows an image of the input signal to the rate conversion filter 4. The sampling rate of the input signal is SR i This shows how the desired signal and the unwanted signal are included in the signal bandwidth of . The figure also shows the frequency gain characteristic of the rate conversion filter 4, and it is assumed that signals in the frequency domain with no gain are removed by the rate conversion filter 4. Figure 5 shows an image of the output signal of the rate conversion filter 4. The sampling rate of the output signal, SR o This shows that the signal bandwidth of does not include any unwanted signals, but only the desired signal. In this way, if there are unwanted signals in the frequency domain removed by the rate conversion filter 4, the power of the output signal will be smaller than the power of the input signal.

[0037] The baseband complex signal output by the rate conversion filter 4 is input to the power adjustment unit 3b. The power adjustment unit 3b multiplies the baseband complex signal by a gain G2 [dB] output by the gain setting unit 8, and outputs the result. The gain multiplication is performed in the same manner as in the power adjustment unit 3a.

[0038] The baseband complex signal output by the power adjustment unit 3b is input to the waveform shaping filter 5. The waveform shaping filter 5 is a filter that is often used in wireless communication of digitally modulated signals to limit the band without causing inter-symbol interference. The processing of the waveform shaping filter 5 may be general processing, so a detailed description will be omitted.

[0039] The baseband complex signal output by the waveform shaping filter 5 is input to the second digital receiving unit 205 as a demodulated signal, where demodulation processing and the like are performed, and information is extracted from the demodulated signal.

[0040] Next, a process of determining a gain used for adjusting the power of a baseband complex signal will be described. The process of determining a gain is performed by the power ratio measuring units 6a to 6c and the correction value calculating units 7a and 7b.

[0041] The output of the quadrature detector 2 is input to the power ratio measuring unit 6a. First, the power ratio measuring unit 6a measures the average power P m1[dB] is calculated using the following formula (2).

[0042]

number

[0043] In equation (2), N is the number of samples in which the power is integrated, n is the sample number (0 to N-1) in which the power is integrated, and si ich,i and si qch,i are the in-phase and quadrature components of the baseband complex signal input to the power ratio measuring unit 6a. The averaging is performed at the period of the trigger T1 input periodically from the trigger generating unit 9, and the number of samples N is the number of samples input during that period. Note that the following calculations are in decibels.

[0044] Next, the power ratio measurement unit 6a calculates the average power P m1 Target power P t1 Power ratio ΔP m1 The target power P is calculated using the following formula (3) and output. t1 is the target power of the baseband complex signal output by the quadrature detection unit 2.

[0045]

number

[0046] The operation of the power ratio measurement unit 6b is the same as that of the power ratio measurement unit 6a, except that the input signal is the output signal of the rate conversion filter 4, the measurement trigger is the trigger T2 input from the trigger generation unit 9, and the target power is the target power P t2 The power ratio measuring unit 6b differs from the power ratio measuring unit 6a in that the power ratio ΔP m2 is calculated using the following formula (4).

[0047]

number

[0048] The operation of the power ratio measurement unit 6c is similar to that of the power ratio measurement unit 6a and the power ratio measurement unit 6b. However, the input signal is the output signal of the waveform shaping filter 5, the measurement trigger is the trigger T3 input from the trigger generation unit 9, and the target power is the target power P tD The power ratio measuring unit 6c differs from the power ratio measuring unit 6a and the power ratio measuring unit 6b in that the power ratio ΔP mD is calculated using the following formula (5).

[0049]

number

[0050] The correction value calculation unit 7a calculates the power ratio ΔP m2 and the power ratio ΔP output by the power ratio measuring unit 6a m1 Then, the correction value ΔP is calculated using the following equation (6). m2,1 Calculate.

[0051]

number

[0052] The correction value calculation unit 7b calculates the power ratio ΔP mD and the power ratio ΔP output by the power ratio measuring unit 6b m2 Then, the correction value ΔP is calculated using the following equation (7). mD,2 Calculate.

[0053]

number

[0054] The gain setting unit 8 calculates the gain G0c currently set in the variable attenuator of the analog receiving unit 202 and the power ratio ΔP m1 Therefore, the gain G set in the variable attenuator of the analog receiving unit 202 is calculated by the following equation (8). 0n Calculate.

[0055]

number

[0056] However, the gain G 0n is the predetermined lower limit G 0Lower If it is less than G 0n =G 0Lower In addition, the gain G 0n is a predetermined upper limit G 0Upper If it is greater than G 0n =G 0Upper Furthermore, gain setting unit 8 calculates a gain difference ΔG0 resulting from this correction using the following equation (9), and uses this to calculate the gain of power adjustment unit 3a.

[0057]

number

[0058] The gain setting unit 8 sets the next gain G 0n The timing at which the gain G0 is output is the timing of the trigger T0 output by the trigger generating unit 9.

[0059] In this way, the gain setting unit 8 determines the gain G0 to be set in the variable attenuator of the analog receiving unit 202, thereby adjusting the power of the baseband complex signal output by the quadrature detection unit 2 to the target power P t1 It can be.

[0060] The gain setting unit 8 also detects the gain G currently set in the power adjustment unit 3a. 1c , the correction value ΔP output by the correction value calculation unit 7a m2,1 From the gain difference ΔG0, the next gain G 1n is calculated using the following formula (10).

[0061]

number

[0062] However, the gain G 1n is the predetermined lower limit G 1Lower If it is less than G 1n =G 1Lower In addition, the gain G is calculated using equation (10). 1n is a predetermined upper limit G 1Upper If it is larger than G 1n =G 1Upper Furthermore, gain setting unit 8 calculates a gain difference ΔG1 resulting from this correction using the following equation (11), and uses this to calculate the gain of power adjustment unit 3b.

[0063]

number

[0064] The gain setting unit 8 sets the next gain G 1n The timing at which this is output as gain G1 is the timing of trigger T1 output by the trigger generating unit 9.

[0065] In this way, the gain setting unit 8 determines the gain G1 to be set in the power adjustment unit 3a, thereby adjusting the power of the baseband complex signal output by the rate conversion filter 4 to the target power P t2 It can be.

[0066] Furthermore, the gain setting unit 8 detects the gain G 2c , the correction value ΔP output by the correction value calculation unit 7b mD,2 , the gain difference ΔG1 is used to determine the next gain G 2n is calculated using the following formula (12).

[0067]

number

[0068] However, the gain G2n is the predetermined lower limit G 2Lower If it is less than G 2n =G 2Lower In addition, the gain G is calculated using equation (12). 2n is a predetermined upper limit G 2Upper If it is greater than G 2n =G 2Upper The gain setting unit 8 corrects the gain G 2n The timing at which the gain G2 is output is the timing of the trigger T2 output by the trigger generating unit 9.

[0069] In this way, the gain setting unit 8 determines the gain G2 to be set in the power adjustment unit 3b, thereby adjusting the power of the baseband complex signal output by the waveform shaping filter 5 to the target power P tD It can be.

[0070] Next, the operation of the trigger generating unit 9 will be described with reference to FIG. 6. FIG. 6 is a diagram showing the output timing of the trigger signal generated by the trigger generating unit 9. FIG. 6 shows the time difference between the output of the variable attenuator of the analog receiving unit 202, the output of the quadrature detection unit 2, the output of the rate conversion filter 4, the output of the waveform shaping filter 5, and the output of the SW detection unit in the demodulation process of the second digital receiving unit 205, together with the frame format of the signal. Note that the SW detection unit outputs a SW detection pulse at the timing when a known signal, SW (Synchronization Word), is detected from the received signal in the demodulation process performed by the second digital receiving unit 205. That is, the second digital receiving unit 205 includes a known signal detection unit that detects a known signal included in the digital received signal and outputs a pulse signal at the timing when the known signal is detected. The process of this known signal detection unit may be a general process, and therefore a detailed description will be omitted.

[0071] 6, a SW, which is a known signal, is placed at the beginning of the frame, and transmission data is placed after the SW. This frame format is just one example, and the position and number of SW are not limited to this.

[0072] 6, the output of the quadrature detector 2 is delayed by a delay time T D1 The output of the rate conversion filter 4 is delayed by the delay time T D2 The output of the waveform shaping filter 5 is delayed by the delay time T D3 The SW detection is delayed by the delay time T SW These delay times are determined by the design of the receiver.

[0073] 6 also shows the timing at which an SW detection pulse is output from an SW detection section (not shown) of the second digital receiving section 205, and the timing at which triggers T0 to T3 are output by the trigger generating section 9. The SW detection pulse is output when the SW finishes being input to the SW detection section, trigger T0 is output at the frame head timing of the signal passing through the variable attenuator of the analog receiving section 202, trigger T1 is output at the frame head timing of the output signal of the quadrature detection section 2, trigger T2 is output at the frame head timing of the output signal of the rate conversion filter 4, and trigger T3 is output at the frame head timing of the output signal of the waveform shaping filter 5.

[0074] The trigger generating unit 9 outputs each trigger when the time calculated by the following formula (13) has elapsed, based on the time when the SW detection pulse was input to the trigger generating unit 9. T fr is the time length of one frame.

[0075]

number

[0076] Although an example has been shown in which each trigger is output from the trigger generating unit 9 at one frame interval, each trigger may be output at multiple frame intervals.

[0077] As a result of trigger generation unit 9 outputting each trigger in this manner, gain setting and power adjustment in the variable attenuator, power adjustment unit 3a, and power adjustment unit 3b of analog receiving unit 202 are always performed at the beginning of the frame of the received signal where power is adjusted, thereby making it possible to suppress power fluctuations within the frame due to deviations in the timing of power adjustment.

[0078] Thus, the wireless receiving device according to the first embodiment includes a first power ratio measurement unit (power ratio measurement unit 6a) that measures the ratio of the power of the digital received signal before rate conversion to the target power, a second power ratio measurement unit (power ratio measurement unit 6b) that measures the ratio of the power of the digital received signal after rate conversion and before waveform shaping to the target power, and a third power ratio measurement unit (power ratio measurement unit 6c) that measures the ratio of the power of the digital received signal after waveform shaping to the target power. Furthermore, the wireless receiving device includes a first power adjustment unit (variable attenuator of analog receiving unit 202) that adjusts the power of the analog received signal before A / D conversion, a second power adjustment unit (power adjustment unit 3a) that adjusts the power of the digital received signal before rate conversion, and a third power adjustment unit (power adjustment unit 3b) that adjusts the power of the digital received signal after rate conversion and before waveform shaping. Then, based on the measurement results by the first power ratio measurement unit, the second power ratio measurement unit and the third power ratio measurement unit, the gain setting unit 8 determines the gains to be set in the first power adjustment unit, the second power adjustment unit and the third power adjustment unit so that the power of the digital received signal before rate conversion, the power of the digital received signal after rate conversion and before waveform shaping, and the power of the digital received signal after waveform shaping each become the target power (i.e., the ratio with respect to the target power becomes 1).

[0079] According to the wireless receiving device of the first embodiment, the decrease in signal level due to rate conversion can be detected at a stage where the sampling frequency is as high as possible, and the power can be adjusted. Therefore, in the automatic gain control when there is an unwanted signal with high power outside the band of the desired signal, the influence of quantization noise can be minimized.

[0080] Furthermore, in the first embodiment, the power measurement averaging intervals of the first power ratio measurement unit (power ratio measurement unit 6a), the second power ratio measurement unit (power ratio measurement unit 6b), and the third power ratio measurement unit (power ratio measurement unit 6c) are configured to be the same, and based on those measurement results, the gain setting and power adjustment by the first power adjustment unit (the variable attenuator of the analog receiving unit 202), the second power adjustment unit (power adjustment unit 3a), and the third power adjustment unit (power adjustment unit 3b) are performed at the beginning of a frame of the received signal, so that level fluctuations within a frame due to power adjustment can be suppressed as much as possible.

[0081] <Embodiment 2> In the first embodiment, the first digital receiving unit 204 includes only one rate conversion filter, but may include multiple rate conversion filters connected in series. In the second embodiment, an example is shown in which the first digital receiving unit 204 includes two rate conversion filters connected in series.

[0082] Fig. 7 is a block diagram of first digital receiving section 204 of a wireless receiving device according to embodiment 2. In the configuration of first digital receiving section 204 in Fig. 7, rate conversion filter 4 is divided into rate conversion filter 4a and rate conversion filter 4b, and a power adjustment section 3c, a power ratio measurement section 6d, and a correction value calculation section 7c are added to the configuration in Fig. 3. Since the other configurations are basically the same as those in Fig. 3, the following mainly describes the points that differ from Fig. 3.

[0083] The rate conversion filter 4a converts the sampling rate of the baseband complex signal output by the power adjustment unit 3a. The power adjustment unit 3b adjusts the power of the baseband complex signal output by the rate conversion filter 4a. The rate conversion filter 4b converts the sampling rate of the baseband complex signal output by the power adjustment unit 3b. The power adjustment unit 3c adjusts the power of the baseband complex signal output by the rate conversion filter 4b. The waveform shaping filter 5 performs waveform shaping of the baseband complex signal output by the power adjustment unit 3c. That is, the first digital receiving unit 204 in FIG. 7 includes two power adjustment units, the power adjustment unit 3b and the power adjustment unit 3c, as a third power adjustment unit that adjusts the power of the digital received signal after rate conversion and before waveform shaping.

[0084] The power ratio measurement unit 6a measures the ratio of the power of the baseband complex signal output by the quadrature detection unit 2 to a target power. The power ratio measurement unit 6b measures the ratio of the power of the baseband complex signal output by the rate conversion filter 4a to a target power. The power ratio measurement unit 6d measures the ratio of the power of the baseband complex signal output by the rate conversion filter 4b to a target power. The power ratio measurement unit 6c measures the ratio of the power of the baseband complex signal output by the waveform shaping filter 5 to a target power. That is, the first digital receiving unit 204 in FIG. 7 includes two power ratio measurement units, the power ratio measurement unit 6b and the power ratio measurement unit 6d, as second power ratio measurement units that measure the ratio of the power of the digital received signal after rate conversion and before waveform shaping to a target power.

[0085] The correction value calculation unit 7a calculates a correction value for the gain setting value to be set in the power adjustment unit 3a from the power ratios output by the power ratio measurement units 6a and 6b. The correction value calculation unit 7b calculates a correction value for the gain setting value to be set in the power adjustment unit 3b from the power ratios output by the power ratio measurement units 6b and 6d. The correction value calculation unit 7c calculates a correction value for the gain setting value to be set in the power adjustment unit 3c from the power ratios output by the power ratio measurement units 6d and 6c.

[0086] Gain setting unit 8 calculates and outputs the gain setting value of the variable attenuator of analog receiving unit 202, the gain setting value of power adjustment unit 3a, the gain setting value of power adjustment unit 3b, and the gain setting value of power adjustment unit 3c from the power ratio output by power ratio measuring unit 6a, the correction value output by correction value calculating unit 7a, the correction value output by correction value calculating unit 7b, and the correction value output by correction value calculating unit 7c. At this time, gain setting unit 8 calculates the gain setting values ​​of the variable attenuator of analog receiving unit 202, the power adjustment unit 3a, the power adjustment unit 3b, and the power adjustment unit 3c so that the power ratios measured by power ratio measuring unit 6a, power ratio measuring unit 6b, power ratio measuring unit 6c, and power ratio measuring unit 6d are each 1.

[0087] The trigger generating section 19 outputs a trigger that defines the reference timing for operation of each of the power ratio measuring sections 6a, 6b, 6c, 6d and the gain setting section 8.

[0088] Next, the operation of the first digital receiving unit 204 in FIG. 7 will be described, mainly focusing on the differences from the first digital receiving unit 204 in FIG.

[0089] In the first digital receiving unit 204 in Fig. 3, the rate conversion filter 4 converts the signal at the sampling rate of the A / D conversion unit 1 to a sampling rate four times the symbol rate, but in the first digital receiving unit 204 in Fig. 7, the rate conversion filter 4a converts from the sampling rate of the A / D conversion unit 1 to a sampling rate 64 times the symbol rate, and the rate conversion filter 4b converts from 64 times the symbol rate to four times the symbol rate. The numerical values ​​of this rate conversion are merely an example, and are not limited to these numerical values.

[0090] The operation of the power adjustment unit 3b is the same as that of the power adjustment unit 3a, except that the input has changed to the baseband complex signal output by the rate conversion filter 4a. For the input baseband complex signal, the power adjustment is performed on the baseband complex signal by the gain G2 output by the gain setting unit 8, and the baseband complex signal is output.

[0091] The operation of the power adjustment unit 3c is the same as that of the power adjustment unit 3a, except that the input has changed to the baseband complex signal output by the rate conversion filter 4b. For the input baseband complex signal, the power of the baseband complex signal is adjusted by the gain G3 output by the gain setting unit 8, and then the baseband complex signal is output.

[0092] The operation of the power ratio measurement unit 6d is similar to that of the power ratio measurement unit 6a, but differs from the power ratio measurement unit 6a in that the input signal is the output signal of the rate conversion filter 4b, the measurement trigger is the trigger T4 input from the trigger generation unit 19, and the target power is the target power Pt3 of the baseband complex signal output from the rate conversion filter 4b. m3 Then, ΔP m3 is expressed by the following equation (14).

[0093]

number

[0094] The correction value calculation unit 7b calculates the power ratio ΔP m3 and the power ratio ΔP output by the power ratio measuring unit 6b m2 Then, the correction value ΔP is calculated using the following equation (15). m3,2 Calculate.

[0095]

number

[0096] The correction value calculation unit 7c calculates the power ratio ΔP mD and the power ratio ΔP output by the power ratio measuring unit 6d m3 Then, the correction value ΔP is calculated using the following equation (16). mD,3 Calculate.

[0097]

number

[0098] The calculation and output of the gains G0 and G1 output by the gain setting unit 8 are the same as in the embodiment 1. The gain G2 is calculated by a method different from that in the embodiment 1. Moreover, in the embodiment 2, it is further necessary to calculate the gain G3.

[0099] The gain setting unit 8 determines the gain G currently set in the power adjustment unit 3b. 2c , the correction value ΔP output by the correction value calculation unit 7b m3,2 , and the gain difference ΔG1, the next gain G 2n is calculated using the following formula (17).

[0100]

number

[0101] However, the gain G 2n is the predetermined lower limit G 2Lower If it is less than G 2n =G 2Lower In addition, the gain G 2n is a predetermined upper limit G 2Upper If it is greater than G 2n =G 2Upper The gain difference ΔG2 resulting from these corrections is calculated by the following equation (18) and used to calculate the gain of power adjustment unit 3c.

[0102]

number

[0103] Next, set the gain G 2n The timing at which the gain G2 is output is the timing of the trigger T4 output by the trigger generating unit 19.

[0104] By determining the gain G2 in this way and setting it in the power adjustment unit 3b, the power of the baseband complex signal output by the rate conversion filter 4b is adjusted to the target power P t2It can be.

[0105] The gain setting unit 8 determines the gain G currently set in the power adjustment unit 3c. 3c , the correction value ΔP output by the correction value calculation unit 7c mD,3 , and the gain difference ΔG2, the next gain G 3n is calculated using the following formula (19).

[0106]

number

[0107] However, the gain G 3n is the lower limit G 3Lower If it is less than G 3n =G 3Lower In addition, the gain G 3n is the upper limit G 3Upper If it is greater than G 3n =G 3Upper and correct it as follows.

[0108] Next, set the gain G 3n The timing at which the gain G3 is output is the timing of the trigger T3 output by the trigger generating unit 19.

[0109] By determining the gain G3 in this way and setting it in the power adjustment unit 3c, the power of the baseband complex signal output by the waveform shaping filter 5 is adjusted to the target power P tD It can be.

[0110] The operation of the trigger generating unit 19 will be described with reference to Fig. 8 in terms of differences from Fig. 6. In Fig. 8, the output of the rate conversion filter 4 is changed to the outputs of the rate conversion filters 4a and 4b in comparison with Fig. 6. Fig. 8 also shows the output delay time T D4 and indicates that a trigger T4 is output at the beginning of a frame of the output of the rate conversion filter 4b.

[0111] The trigger generating unit 19 outputs each trigger when the time calculated by the following formula (20) has elapsed, based on the time when the SW detection pulse was input to the trigger generating unit 19. fr is the duration of one frame.

[0112]

number

[0113] Although an example has been shown in which each trigger is output from the trigger generating unit 19 at one frame interval, each trigger may be output at a multiple frame interval.

[0114] As a result of trigger generation unit 19 outputting each trigger in this manner, power adjustment in variable attenuator, power adjustment unit 3a, power adjustment unit 3b and power adjustment unit 3c of analog receiving unit 202 is always performed at the beginning of a frame, thereby making it possible to suppress power fluctuations within a frame due to deviations in the timing of power adjustment.

[0115] Thus, the radio receiving apparatus according to the second embodiment includes a plurality of rate conversion filters (rate conversion filter 4a and rate conversion filter 4b), a plurality of second power ratio measurement units (power ratio measurement units 6b and power ratio measurement units 6d), and a plurality of third power adjustment units (power adjustment units 3b and power adjustment units 3c). The plurality of second power ratio measurement units measure the ratio of the power of the digital reception signal output by each of the plurality of rate conversion filters to the target power. The plurality of third power adjustment units adjust the power of the digital reception signal output by each of the plurality of rate conversion filters. The gain setting unit 8 determines the gains to be set in the first power adjustment unit, the second power adjustment unit, and the plurality of third power adjustment units based on the ratios measured by each of the first power ratio measurement unit, the plurality of second power ratio measurement units, and the third power ratio measurement unit so that the ratios become 1.

[0116] According to the wireless receiving device of the second embodiment, by performing rate conversion of a digital received signal in stages using a plurality of rate conversion filters, it is possible to detect and adjust a decrease in signal level due to filter processing at a stage where the sampling frequency is higher than that of the first embodiment. Therefore, it is possible to minimize the influence of quantization noise in automatic gain control when there is an unwanted signal with high power outside the band of a desired signal.

[0117] It should be noted that the embodiments can be freely combined, and each embodiment can be modified or omitted as appropriate.

[0118] <Additional Notes> Various aspects of the present disclosure are summarized below as appendices.

[0119] (Appendix 1) An A / D conversion unit that performs A / D conversion to convert an analog received signal into a digital received signal; a rate conversion filter that performs rate conversion to convert a sampling rate of the digital received signal into a sampling rate required for demodulation processing; a waveform shaping filter for shaping a waveform of the digital reception signal after the rate conversion; a first power ratio measurement unit that measures a ratio of the power of the digital received signal before the rate conversion to a target power; a second power ratio measurement unit that measures a ratio of the power of the digital received signal after the rate conversion and before the waveform shaping to a target power; a third power ratio measurement unit that measures a ratio of the power of the digital reception signal after the waveform shaping to a target power; a first power adjustment unit that adjusts the power of the analog received signal before the A / D conversion; a second power adjustment unit that adjusts the power of the digital received signal before the rate conversion; a third power adjustment unit that adjusts the power of the digital received signal after the rate conversion and before the waveform shaping; a gain setting unit that determines gains to be set in the first power adjustment unit, the second power adjustment unit, and the third power adjustment unit based on the ratios measured by the first power ratio measurement unit, the second power ratio measurement unit, and the third power ratio measurement unit so that the ratios become 1; Equipped with Radio receiving device.

[0120] (Appendix 2) a plurality of the rate conversion filters, the second power ratio measurement units, and the third power adjustment units; The rate conversion filters are connected in series, the second power ratio measurement units measure a ratio of the power of the digital received signal output from each of the rate conversion filters to a target power; the third power adjustment units adjust the power of the digital received signals output from the rate conversion filters, respectively; the gain setting unit determines gains to be set in the first power adjustment unit, the second power adjustment unit, and the third power adjustment units based on ratios measured by the first power ratio measurement unit, the plurality of second power ratio measurement units, and the third power ratio measurement unit so that the ratios become 1. 2. A wireless receiving device as described in claim 1.

[0121] (Appendix 3) a known signal detection unit that detects a known signal included in the digital received signal and outputs a pulse signal at the timing when the known signal is detected; a trigger generating unit that outputs a trigger that defines a timing at which a gain is set in each of the first power adjusting unit, the second power adjusting unit, and the third power adjusting unit, based on a timing of the pulse signal; Further equipped with the gain setting unit outputs the trigger so that the timing at which the gain is set in each of the first power adjustment unit, the second power adjustment unit, and the third power adjustment unit coincides with the timing of a frame head of the analog reception signal or the digital reception signal for which power is to be adjusted. 3. A wireless receiving device according to claim 1 or 2. [Explanation of symbols]

[0122] 1 A / D conversion unit, 2 quadrature detection unit, 3a to 3c power adjustment unit, 4, 4a, 4b rate conversion filters, 5 waveform shaping filter, 6a to 6d power ratio measurement unit, 7a to 7c correction value calculation unit, 8 gain setting unit, 9, 19 trigger generation unit, 100 base station, 101 mobile station, 102 control station, 103 communication area, 200 wireless receiving device, 201 antenna, 202 analog receiving unit, 203 digital receiving unit, 204 first digital receiving unit, 205 second digital receiving unit.

Claims

1. An A / D conversion unit that performs A / D conversion to convert an analog received signal into a digital received signal; a rate conversion filter that performs rate conversion to convert a sampling rate of the digital received signal into a sampling rate required for demodulation processing; a waveform shaping filter for shaping a waveform of the digital reception signal after the rate conversion; a first power ratio measurement unit that measures a ratio of the power of the digital received signal before the rate conversion to a target power; a second power ratio measurement unit that measures a ratio of the power of the digital received signal after the rate conversion and before the waveform shaping to a target power; a third power ratio measurement unit that measures a ratio of the power of the digital reception signal after the waveform shaping to a target power; a first power adjustment unit that adjusts the power of the analog reception signal before the A / D conversion; a second power adjustment unit that adjusts the power of the digital received signal before the rate conversion; a third power adjustment unit that adjusts the power of the digital received signal after the rate conversion and before the waveform shaping; a gain setting unit that determines gains to be set in the first power adjustment unit, the second power adjustment unit, and the third power adjustment unit based on the ratios measured by the first power ratio measurement unit, the second power ratio measurement unit, and the third power ratio measurement unit so that the ratios become 1; Equipped with Radio receiving device.

2. the rate conversion filter, the second power ratio measurement unit, and the third power adjustment unit are each provided in a plurality of units; The rate conversion filters are connected in series, the second power ratio measurement units measure a ratio of the power of the digital received signal output from each of the rate conversion filters to a target power; the third power adjustment units adjust power of the digital received signals output from the rate conversion filters, respectively; the gain setting unit determines gains to be set in the first power adjustment unit, the second power adjustment unit, and the third power adjustment unit based on ratios measured by the first power ratio measurement unit, the second power ratio measurement unit, and the third power ratio measurement unit, so that the ratios become 1.

2. The wireless receiving device according to claim 1.

3. a known signal detection unit that detects a known signal included in the digital received signal and outputs a pulse signal at the timing when the known signal is detected; a trigger generating unit that outputs a trigger that defines a timing at which a gain is set in each of the first power adjusting unit, the second power adjusting unit, and the third power adjusting unit, based on a timing of the pulse signal; Further equipped with the gain setting unit outputs the trigger so that the timing at which the gain is set in each of the first power adjustment unit, the second power adjustment unit, and the third power adjustment unit coincides with the timing of a frame head of the analog reception signal or the digital reception signal for which power is to be adjusted.

3. The wireless receiving device according to claim 1 or 2.

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