WO2008050391A1 - Radio signal receiving apparatus - Google Patents

Abstract

A radio signal receiving apparatus wherein an AGC control circuit is realized which prevents the amplitudes of input signals to be supplied to a reception amplifier and an A/D converter from being saturated even if the arrival time and/or reception level of a burst signal is unknown. This apparatus includes two types of average amplitude determining elements (102,106) that determines input and output average amplitudes of a variable gain amplifier (101). A result of output average amplitude determination by the first average amplitude determining element (102) is used to cause the variable gain amplifier (101) to effect a variable gain control. When a result of input signal amplitude determination by the second average amplitude determining element (106) is lower than a reference value, the reference value is used to cause the variable gain amplifier (101) to effect a constant gain control. At this moment, switching from the variable gain control to the constant gain control is effected by a switch (154).

Description

 Specification

 Wireless signal receiver

 Technical field

 TECHNICAL FIELD [0001] The present invention relates to a radio signal receiving apparatus that is a radio signal receiving means in a mobile communication apparatus such as a mobile phone and a radio signal transmission system such as a wireless LAN, and more particularly, a burst signal that is an intermittent radio signal. The present invention relates to a radio signal receiving apparatus that receives

 Background art

 [0002] Data transmission methods in the second and third generation mobile communication systems are mainly circuit switching methods, but the ratio of data communication other than voice communication has increased, and equipment costs have been reduced. Internet-Protocol (IP) has been developed for this purpose. Therefore, with the advancement of IP, packet switching is becoming the mainstream for data transmission in next-generation mobile communication systems. In addition, the bandwidth of next-generation wireless communication is increasing to several hundreds of kHz and several tens of MHz, and the frequency multiplexing technology is used for upstream signals in addition to the time division multiplexing technology.

 [0003] In addition, as one of the technical issues of radio station apparatuses that receive uplink radio signals from a plurality of terminals such as base station apparatuses of mobile communication systems and access point (AP) apparatuses of wireless LANs, AGC (Auto-Gain-Control) There is a wide dynamic range of control. For example, the level of the uplink radio signal from each terminal in a mobile communication system varies about 70 to 90 dB in power level due to variations in the distance between terminal radio station devices and the transmission environment. Furthermore, since the signals of a plurality of terminals overlap in time in the radio station apparatus, the level fluctuation of the received signal of the radio station apparatus becomes even larger.

[0004] In addition, a radio station apparatus that receives uplink radio signals collectively receives signals transmitted from a plurality of terminals in this way, and collectively converts the received signals to analog Z digital (A / D) conversion. After that, the signal from each terminal is separated by digital signal processing. However, in general, the dynamic range of the input of the AZD converter is narrower than 70 dB, so that the AZD conversion does not occur due to the CNR (Carrier Noise Ratio) deterioration in the AZD conversion or the input level saturation. It is necessary to optimally adjust the input level. in this way AGC control is the optimum adjustment of the input level of the AZD variable ^^ using a variable gain amplifier.

 [0005] Also, in the uplink reception system as described above, for example, a TDMA (Time-Division-Multiple-Access) system or a CDMA (Code-Division-Multiple-Access system) is used as a communication system. In the TDMA system used in second-generation mobile communication systems and wireless LANs, terminals share the same frequency band, and uplink signals from each terminal overlap in time in the radio station equipment. On the other hand, in the CDMA system, each terminal shares the same frequency band, and the signals of each terminal overlap in time, but in the radio station apparatus, the spreading assigned to each terminal is performed. The signal for each terminal can be separated by the code, and in the third generation W-CDMA, the uplink transmission is a circuit switching method using the C DMA method, so that the received signal The level of the Therefore, there was no major problem with the AGC control of the receiver.

 [0006] On the other hand, in the TDMA system, the received signal arriving from each terminal is a burst signal in units of time called a frame or a packet, and therefore, the level fluctuation of the rising edge and falling edge of the frame is extremely large. This makes A GC control difficult at the rising edge and falling edge of the frame. In other words, the rise and fall times of the frame are much faster than the time constant of the AGC control, so immediately after the rise of the frame, the input power of the AZD converter is too large and the variable gain amplifier saturates and the frame Immediately after the fall, the AZD variable input power is too small and the CNR in the variable gain amplifier deteriorates, making it difficult to perform optimal AGC control.

[0007] Techniques relating to burst signal reception methods for solving such AGC control problems are disclosed in Patent Document 1, for example. Fig. 1 is a block diagram of an AGC control circuit in a conventional radio signal receiver. As shown in FIG. 1, the switching switch 17 uses the AGC voltage (X) of the current burst signal of the AGC circuit 16 as the control voltage of the variable gain amplifier 1 and the previous frame stored in the storage circuit 19. After comparing the AGC voltage (Y) of the burst signal, the AGC voltage (X) of the current burst signal and the AGC voltage (Y) of the burst signal one frame before are switched appropriately. [0008] That is, the AGC voltage (X) of the current burst signal and the A GC voltage (Y) of the burst signal one frame before are compared by the level difference detector 18, and the difference between X and Y is less than a certain value Z When (ie, when I XY I ≤Z), switch the output of switch 17 to the AGC voltage (X) of the current burst signal. When the difference between X and Y is greater than a certain value Z (that is, when I XY I> Z), the output of switch 17 is switched to the AGC voltage (Y) of the burst signal one frame before. In other words, the switching switch 17 switches to the AGC voltage (X) of the current burst signal detected by the AGC circuit 16 when there is a burst signal and transmits it to the control terminal of the variable gain amplifier 1, and when there is no burst signal, The AGC voltage (Y) of the burst signal one frame before stored in the memory circuit 19 is switched to and transmitted to the control terminal of the variable gain amplifier 1. The switching control of the switching switch 17 as described above is performed according to the cycle of the timing signal generated by the timing generator 20.

 [0009] Thereby, at the rising edge of the burst signal, it is possible to shorten the time until the AGC control operates, and to suppress the discontinuity of the AGC control voltage caused by the intermittent burst signal. In the conventional TDMA scheme, the transmission station and the reception frame are alternately time-multiplexed in the radio station apparatus, and therefore the reception timing time is known to the radio station apparatus.

 Patent Document 1: JP-A-9-186539

 Disclosure of the invention

 Problems to be solved by the invention

 [0010] However, the burst signal reception method in the AGC control circuit as described above is based on the premise that the arrival time of the reception signal (burst signal) is previously weak. If there is no burst signal, the above AGC control cannot be applied. Also, in wireless communication in next-generation mobile communication systems, signal transmission speeds will increase and IP will become more advanced and packet switching will occur, so the upstream signal will necessarily be a burst signal. Become. At this time, if the transmission timing is controlled by the radio station apparatus so that the burst signal of each terminal does not arrive at random, the time of the reception timing becomes known.

[0011] However, today, in addition to the TDMA method, a CD is used to increase the transmission efficiency of upstream signals. The combined use of the MA method and FDMA method is being studied, and in this case, it is necessary to receive the signal with a mix of the uplink signals from multiple terminals, so the receiver amplifier (variable gain amplifier 1) and the AZD conversion The received signal level fluctuates greatly as compared with the prior art. That is, the amplitude of the rising edge of the burst signal has no correlation with that of the past burst signal. Therefore, in conventional signals such as Patent Document 1 above, the control signal one frame before is not an appropriate value in many cases, and deterioration due to saturation occurs in the receiving amplifier and AZD converter in the subsequent stage. May occur.

The present invention has been made in view of such circumstances, and even when the arrival time of the burst signal or the reception power Z reception level is unknown, the input signal of the reception amplifier or the AZD converter The purpose is to realize a wireless signal receiver with an AGC control circuit that does not saturate the amplitude of the signal.

 Means for solving the problem

[0013] A radio signal receiving apparatus of the present invention is a radio signal receiving apparatus that receives and amplifies burst signals transmitted from a plurality of terminal apparatuses, and has a power that varies a power amplification factor of the burst signal. Variable means and first amplitude detection means for detecting an output average amplitude of the burst signal output from the power variable means by a detection circuit having a first time constant longer than the rise time of the amplitude of the burst signal And second amplitude detection means for detecting an input average amplitude of the burst signal input to the power variable means by a detection circuit having a second time constant longer than the rise time of the amplitude of the burst signal, Error detection means for obtaining an error detection value that is a difference between the output average amplitude and the first reference value; and when the input average amplitude is equal to or less than a second reference value, A switching means for causing the variable means to perform constant gain control and causing the power variable means to perform variable gain control by the error detection value when the input average amplitude is greater than the second reference value. take.

 The invention's effect

[0014] The present invention provides a radio signal receiving apparatus that receives radio burst signals transmitted from a plurality of terminals, and includes two types of amplitude detectors for an input signal and an output signal of a variable gain amplifier (power variable means). Equipped with output signal amplitude (average output amplitude) detection result V, let the variable gain amplifier perform AGC control, and when the detection result of the input signal amplitude (input average amplitude) is low, switch the variable gain amplifier to perform constant gain control from AGC control . As a result, no matter what size burst signal arrives or when the burst signal arrives at an unexpected timing, the deterioration of the characteristics due to the saturation of the receiving amplifier and AZ D change ^^ Can be prevented. In addition, since the above two types of amplitude detectors require high-speed response, an AGC control circuit can be realized with an inexpensive circuit configuration.

 Brief Description of Drawings

[0015] FIG. 1 is a block diagram of an AGC control circuit in a conventional radio signal receiver.

 FIG. 2 is a block diagram of an AGC control circuit in the radio signal receiving apparatus according to Embodiment 1 of the present invention.

 FIG. 3 is a diagram illustrating an example of time variation of a control signal when variable gain control is performed on a burst signal.

FIG. ₄ is a diagram showing an example of a time variation of a control signal when variable gain control and constant gain control are performed in combination with a burst signal.

 FIG. 5 is a block diagram of an AGC control circuit in the radio signal receiving apparatus according to Embodiment 2 of the present invention.

 BEST MODE FOR CARRYING OUT THE INVENTION

 <Outline of the Invention>

 In the AGC control circuit in the radio signal receiving apparatus of the present invention, when the amplitude of the received burst signal is larger than a predetermined level, the variable gain amplifier performs variable gain control by a feedback system, and the received burst signal has an amplitude of a predetermined level. When smaller, the variable gain amplifier performs constant gain control. As a result, even when the arrival time of the received burst signal is unknown, it is possible to prevent characteristic deterioration due to saturation of the variable gain amplifier and the subsequent AZD converter.

Next, some specific embodiments of the radio signal receiving apparatus according to the present invention will be described in detail. Note that, in the drawings used in the following embodiments, the same components are denoted by the same reference numerals, and redundant descriptions are omitted as much as possible. <Embodiment 1>

 FIG. 2 is a block diagram of an AGC control circuit in the radio signal receiving apparatus according to Embodiment 1 of the present invention. This AGC control circuit is provided in front of the variable gain amplifier 101, which is a receiving amplifier, or an AZD converter (not shown) in the subsequent stage of the variable gain amplifier 101, and reduces characteristics deterioration due to saturation of the input burst signal. It is to suppress.

 First, the configuration of the AGC control circuit shown in FIG. 2 will be described. This AGC control circuit includes a variable gain amplifier 101, a first average amplitude detector 102, a first AZD converter 103, a first reference value 104, an error detector 105, and a second average amplitude. A detector 106, a third reference value 107, a control signal generator 108, and a low-pass filter (LPF) 109 are provided. The control signal generator 108 includes a second AZD converter 151, a second reference value 152, a comparator 153, a switching switch 154, and a DZA converter 155.

 [0020] The variable gain amplifier 101 varies the power amplification rate of a burst signal transmitted by radio with a plurality of terminal powers, and amplifies the power to an optimum level. The first average amplitude detector 102 detects the output average amplitude of the burst signal output from the variable gain amplifier 101 and has a time constant (first time constant) longer than the rise time of the amplitude of the burst signal. Detect by circuit. The first AZD converter 103 converts the output average amplitude of the burst signal detected by the first average amplitude detector 102 into a digital signal with analog signal power.

 The error detector 105 compares the first amplitude detection value (output average amplitude) detected by the first average amplitude detector 102 with the first reference value 104 to generate an error detection value. The first reference value 104 is a reference value for causing the variable gain amplifier 101 to perform variable gain control.

 [0022] The second average amplitude detector 106 has a time constant (second time constant) that is longer than the rise time of the amplitude of the burst signal for the input average amplitude of the burst signal input to the variable gain amplifier 101. It is detected by a detection circuit.

[0023] The third reference value 107 is a constant gain control so that the variable gain amplifier 101 and the AZD variation (not shown) on its output side are not saturated in preparation for the sudden arrival of a burst signal. This is a reference value of the control signal level to be performed.

[0024] The second AZD variable l51 in the control signal generator 108 is a second average amplitude detector 10. Converts the average input amplitude of the burst signal detected by 6 into an analog signal strength digital signal. The second reference value 152 is a threshold value for determining whether or not the variable gain amplifier 101 performs force gain variable control for performing constant gain control. The comparator 153 compares the output value (input average amplitude) of the second average amplitude detector 106 with the second reference value 152. The switch 154 switches the control signal input to the control terminal of the variable gain amplifier 101 to either the error detection value from the error detector 105 or the third reference value. In other words, the switch 154 switches the input to the control terminal of the variable gain amplifier 101 when the output value (input average amplitude) of the second average amplitude detector 106 is equal to or smaller than the second reference value 152. When the reference value 107 ^ is switched and the output value (input average amplitude) of the second average amplitude detector 106 is greater than the second reference value 152, the input to the control terminal of the variable gain amplifier 101 is an error from the error detector 105. Switch to the detected value. The DZA converter 155 converts the control signal transmitted from the switch 154 to the variable gain amplifier 101 into a digital signal force as well as an analog signal.

 The LPF 109 is inserted between the variable gain amplifier 101 and the control signal generator 108, and eliminates the discontinuity of the control signal when switching the variable gain control and the constant gain control by the switch 154.

 Next, the operation of the AGC control circuit shown in FIG. 2 will be described. Variable gain amplifier 101 Power Amplifies a received signal (burst signal) that has received a plurality of terminal powers (not shown). At this time, the gain control of the variable gain amplifier 101 is performed using the control signal from the control signal generator 108. The AGC control circuit of the present invention is configured in such a combination that the variable gain amplifier 101 performs two types of control, variable gain control and constant gain control. Note that a variable attenuator may be used instead of the variable gain amplifier 101. However, in the following embodiment, a case where variable gain control and constant gain control are performed using the variable gain amplifier 101 will be described.

First, the operation of variable gain control performed by the variable gain amplifier 101 will be described. A first average amplitude detector 102 detects the amplitude of the burst signal at the output of the variable gain amplifier 101. The amplitude detection value (output average amplitude) of the burst signal detected by the first average amplitude detector 102 is converted into a digital signal by the first AZD conversion 103, Input to the comparison terminal of the error detector 105. Then, the error detector 105 obtains a difference (error detection value) between the amplitude detection value (output average amplitude) and the first reference value 104. The error signal of the difference (error detection value) is input as a feedback signal from the control signal generator 108 to the control terminal of the variable gain amplifier 101.

 [0028] That is, the control signal generator 108 has a built-in switching switch 154, and in variable gain control, the switching switch 154 switches to the b-contact side, and an error detection signal of as much as 105 errors is detected. Is input to the control terminal of the variable gain amplifier 101 to perform feedback control. As a result, AGC control is performed so that the average amplitude of the output signal (burst signal) of the variable gain amplifier 101 becomes constant.

 [0029] Here, assuming that the first time constant in the AGC control of the feedback loop by the first average amplitude detector 102 is T1, the first time constant T1 is sufficiently larger than the rise time of the burst signal. Increase the length so that the amplitude information of the burst signal is not lost by the above AGC control. Since the time constant of the AGC control is usually dominated by the first time constant T1 in the first average amplitude detector 102, the time constant is set in the first average amplitude detector 102. This can be realized by making the detection average time longer than the rise time. If the time constant due to the delay time of the above feedback loop cannot be ignored, the first time constant T1 is determined taking this into consideration. The components of the variable gain control and the AGC control by such a variable gain amplifier 101 are the same as those in the prior art, so a detailed description is omitted.

 [0030] In the AGC control as described above, since an instantaneous rise of the signal amplitude of the burst signal cannot be detected, it causes a characteristic deterioration. Here, the cause of the characteristic degradation due to the instantaneous rise of the signal amplitude of the burst signal is described. FIG. 3 is a diagram illustrating an example of the time change of the control signal when variable gain control is performed on the burst signal, with the horizontal axis indicating time and the vertical axis indicating the signal level.

In FIG. 3, the dotted line waveform represents the waveform of the burst signal input to the variable gain amplifier 101, and the solid line waveform represents the time variation of the reciprocal of the gain when variable gain control is performed. In other words, the solid line waveform corresponds to the time average by the first time constant T1 of the amplitude of the burst signal, and the number of burst signals arriving per unit time is increased. The signal level increases as the intensity increases. In other words, the solid line waveform represents the temporal change in the control signal level input to the control terminal of the variable gain amplifier 101.

 [0032] In FIG. 3, when the number of burst signals indicated by dotted lines is small and the time domain is A, in time domain A, the control signal level indicated by the solid line is small and the gain of the variable gain amplifier 101 is large. Therefore, the amplitude at the moment when the burst signal arrives becomes very large compared to the average amplitude (that is, the control signal level in the solid line in the figure), and the input of the variable gain amplifier 101 and the AZ D converter (not shown) at the subsequent stage Is easily saturated. That is, since the level fluctuation at the rising edge of the burst signal is too large, the input of the variable gain amplifier 101 or the AZD converter (not shown) at the subsequent stage may be saturated.

 [0033] On the other hand, if the time region where the number of burst signals indicated by the dotted line in the figure is large is B, in this time region B, the amplitude and average amplitude at the rising edge of the burst signal (that is, the control signal of the solid line in the figure) The difference from level) is very small compared to time domain A. Therefore, saturation can be prevented by setting the input levels of the variable gain amplifier 101 and the AZD converter (not shown) in the subsequent stage low.

 [0034] From the above, there is a problem that the variable gain amplifier 101 and the AZD transformation (not shown) in the subsequent stage are saturated in the time domain A where the number of burst signals is small only by the variable gain control described above. Arise.

 [0035] Next, in order to solve such a problem, a method of performing constant gain control in the time domain A with a small number of burst signals will be described.

That is, the constant gain control of the variable gain amplifier 101 is performed only during the time domain A shown in FIG. This method will be described with reference to FIG. The second average amplitude detector 106 detects the temporal input average amplitude of the burst signal that is the input signal of the variable gain amplifier 101, and the second AZD converter 151 of the control signal generator 108 detects this input average amplitude. After the detected value is converted into an analog signal power as well as a digital signal, the comparator 153 compares the detected value of the input average amplitude with the second reference value 152. Here, when the detected value of the input average amplitude detected by the second average amplitude detector 106 is larger than the second reference value 152, it is determined that it is in the time domain B, and the above variable gain control is performed. Switch 154 to contact b Turn towards (change.

 [0037] On the other hand, if the detected value of the input average amplitude detected by the second average amplitude detector 106 is equal to or smaller than the second reference value 152, it is determined that it is in the time domain A, and the switch 154 is connected to the contact point. Switch to a (instead, let the variable gain amplifier 101 perform constant gain control.

 Here, the control voltage value at the time of the constant gain control is stored as the third reference value 107, and the burst signal reaches the third reference value, that is, the gain at the constant gain control, suddenly. Then, the value is set to a value sufficiently small so that the variable gain amplifier 101 and the AZD transformation (not shown) in the subsequent stage are not saturated.

 [0039] FIG. 4 is a diagram showing an example of a time change of a control signal when variable gain control and constant gain control are performed in combination with a burst signal, with time on the horizontal axis and signal level on the vertical axis. Is shown. In this case, as shown in FIG. 4, even if a burst signal suddenly arrives in time domain A, the control signal level does not become too small, that is, the gain of variable gain amplifier 101 does not increase. Also, keep the control signal level constant! Therefore, saturation can be prevented by setting the input level of the variable gain amplifier 101 and the subsequent AZD converter (not shown) to a low level.

 Note that the second time constant T2 of the second average amplitude detector 106 is set to be substantially the same value as the first time constant T1 of the first average amplitude detector 102. That is, if the second time constant T2 is shorter or longer than the first time constant T1, the time domain A and time domain B cannot be properly determined. That is, if the second time constant T2 is too long, the time domain A decreases, and the variable gain amplifier 101 and the AZD conversion (not shown) in the subsequent stage are likely to be saturated. On the other hand, if the second time constant T2 is short, the time domain A will increase and it will be difficult to saturate. In addition, in order to shorten the second time constant T2, it is necessary to detect the amplitude at high speed, which causes problems such as an expensive circuit configuration. Therefore, it is desirable that the second time constant T2 of the second average amplitude detector 106 is set to be approximately the same value as the first time constant T1 of the first average amplitude detector 102.

Further, as shown in FIG. 2, a low-pass filter 109 is inserted between the variable gain amplifier 101 and the control signal generator 108. As a result, variable gain control using the switching switch 154 and As a result, it is possible to eliminate the discontinuity of the control signal when the constant control is switched. At this time, the third time constant T3 of the one-pass filter 109 is substantially equal to the first time constant T1 of the first average amplitude detector 102 and the second time constant T2 of the second average amplitude detector 106. It is desirable to set the same level. In other words, if the third time constant T3 of the low-pass filter 109 is too long, the AGC control speed in the time domain A is slow, and conversely, if the third time constant T3 of the low-pass filter 109 is too short, the gain control It causes problems such as deterioration of the signal waveform due to discontinuity of the control signal at the time of switching.

 [0042] As described above, the power described in Fig. 2 for the AGC control circuit by digital signal processing using an AZD converter, etc. By this digital processing, the AGC control circuit is compacted by a single chip. Can be realized, and an analog signal processing circuit can be used if necessary.

 [0043] Although the above uses a method of detecting the average signal amplitude of the first time constant T1 of the first average amplitude detector 102 as a method of detecting the signal level for performing the AGC control, Instead, the same effect can be obtained by using a peak amplitude detector with a long time constant. The reason is that the peak detection result of the first time constant T1 changes with time almost the same as the average amplitude detection result of the first time constant T1. What is needed here is a slow peak detector with a first time constant, T1, that is not possible with a fast peak detector. In other words, since a high-speed peak detector is expensive and cannot be used because amplitude information is lost, a slow peak detector with the first time constant T1 is useful.

 [0044] As described above, the saturation at the rising edge of the burst signal of the receiving amplifier (that is, the variable gain amplifier 101) or the AZD converter is achieved by the gain control method combining the variable gain control and the constant gain control. Can be prevented. In addition, such a gain control method does not require an expensive high-speed signal level detector for detecting the rising edge of the burst signal, and the signal processing is very simple. It is possible to reduce the size and cost of the receiving device.

 <Embodiment 2>

FIG. 5 is a block diagram of an AGC control circuit in the radio signal receiving apparatus according to Embodiment 2 of the present invention. The difference from the first embodiment shown in FIG. 2 is that the control performs constant gain control. It is the setting method of the 3rd reference value which determines a signal level. For this purpose, a terminal number detector 201 and an F (N) calculator 202 are added. Except for this, redundant description that is the same as in Embodiment 1 is omitted.

 In FIG. 5, a terminal number detector 201 that detects the number N of terminals detects the number N of terminals that are communicating with a radio base station (not shown). Since it is common for a radio base station to always know the number of mobile terminals in communication and perform communication control, it is not usually necessary to install a new detector. Therefore, the information on the number N of communicating terminals can be easily obtained from the communication control information of the radio base station.

 [0047] Next, the F (N) calculator 202 calculates a monotonically increasing function F (N) related to the number N of terminals detected by the terminal number detector 201, and sets the calculation result as the third reference value 107a. . This third reference value 107a is the amplitude of the burst signal so that the subsequent receiving amplifier and AZD variation are not saturated by the burst signal that suddenly arrives in time domain A shown in Fig. 3. The predicted value is set. The greater the number N of terminals in communication with the radio base station, the more likely the burst signal will arrive simultaneously. The larger the number N of terminals, the larger the third reference value 107a is. Therefore, the monotonically increasing function F (N) is a function that monotonically increases with the number of terminals N.

 [0048] Next, an example of a setting method related to the dependency of the monotonically increasing function F (N) on the number N of terminals will be described. Assuming the possibility of receiving N signals at the same time when the number of terminals registered and connected to the radio base station is always assumed, the amplitude of the rising edge of the burst signal is proportional to. The increase function F (N) is obtained by the following equation (1). This is the simplest setting method.

 F (N) = b 'N (1)

 Industrial applicability

[0049] According to the radio signal receiving apparatus of the present invention, burst signal transmission will become more common in next-generation radio transmission systems, and fluctuations in received signal amplitude will increase, so that the receiving amplifier and AZD conversion will be saturated. The need for AGC control that does not occur is increasing. The present invention is a wireless signal receiving device having an AGC circuit that does not saturate the input signal amplitude of a receiving amplifier or AZD converter even when the arrival time or received power of a burst signal is unknown. Is effective in the next-generation radio station apparatus.

Claims

The scope of the claims  [1] A plurality of terminal device power wireless signal reception devices that receive and amplify burst signals transmitted wirelessly,  Power varying means for varying the power amplification factor of the burst signal;  A first amplitude detecting means for detecting an output average amplitude of the burst signal to be output by a detection circuit having a first time constant longer than a rise time of the amplitude of the burst signal;  Second amplitude detection means for detecting an input average amplitude of a burst signal input to the power variable means by a detection circuit having a second time constant longer than the rise time of the amplitude of the burst signal;  Error detection means for obtaining an error detection value which is a difference between the output average amplitude and the first reference value;  When the input average amplitude is less than or equal to the second reference value, the power variable means performs constant gain control with a third reference value, and when the input average amplitude is greater than the second reference value, A radio signal receiving apparatus comprising: a switching unit that causes the power variable unit to perform variable gain control according to an error detection value.  2. The radio signal receiving device according to claim 1, wherein the first time constant and the second time constant are substantially the same.  [3] a terminal number detecting means for detecting the number of terminals in communication with the wireless signal receiving device;  The radio signal receiving apparatus according to claim 1, further comprising: a monotonically increasing function calculating unit that determines the third reference value based on a calculation result of a monotonically increasing function based on the number of terminals detected by the terminal number detecting unit.