JP2012165164A - Wireless device and noise processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wireless device and a noise processing method which can restrict degradation of reception characteristics of transmitted signals caused by power fluctuations.SOLUTION: The wireless device comprises: an LNA which outputs a receive signal received using an RF unit; a Rx oscillator which generates a reception use local signal; a buffer amp which can change the level of the reception use local signal; a conversion circuit which mixes the reception use local signal and the received signal to generate a demodulation use receive signal; a transmit unit which transmits a transmit signal; a transmission processing unit which sets the power of a transmit signal; a difference calculation unit which calculates a difference between the power set by the transmission processing unit and the power which was set immediately preceding it; and a noise processing unit which raises the level of the reception unit local signal above a prescribed level if the power difference exceeds a fluctuation threshold, or lowers the level of the reception unit local signal to a prescribed level if the power difference does not exceed a fluctuation threshold.

Description

  The present invention relates to a radio apparatus and a noise processing method.

  In a communication system such as WCDMA (Wideband Code Division Multiple Access) and LTE (Long Term Evolution) that employs an FDD (Frequency Division Duplex) method, transmission and reception of radio waves may be performed simultaneously.

  Patent Document 1 describes a wireless device that demodulates a reception signal during transmission of a transmission signal. A wireless device described in Patent Literature 1 includes an oscillator that oscillates a local signal, a variable amplifier that amplifies and outputs the local signal, a mixer that mixes the received signal and the local signal, and a reception that is mixed by the mixer. A demodulator that demodulates the signal, a modulator that outputs the transmission signal, and a detection circuit that detects the level of the transmission signal are provided.

  The wireless device described in Patent Document 1 raises the level of the local signal output from the variable amplifier when the level of the transmission signal detected by the detection circuit is high. Therefore, even if the transmission signal leaks to the mixer and the transmission signal is superimposed as noise on the reception signal mixed by the mixer, the reception characteristics of the reception signal are prevented from deteriorating.

JP 2003-283361 A

  In the wireless device described in Patent Document 1, in addition to the transmission signal leaking to the mixer and noise being superimposed on the reception signal, noise is also superimposed on the reception signal due to a sudden fluctuation in the power of the transmission signal. . For this reason, there has been a problem that reception characteristics deteriorate when the power of the transmission signal fluctuates rapidly.

  An object of the present invention is to provide a radio communication apparatus and a communication method that suppress degradation of reception characteristics caused by fluctuations in power of a transmission signal.

  The wireless communication apparatus of the present invention includes a receiving unit that outputs a received signal received using an antenna unit, a generating unit that generates a local signal mixed with the received signal, and a variable that can change the level of the local signal. Amplifying means; mixing means for mixing the local signal and the reception signal to generate a reception signal for demodulation; transmission means for transmitting a transmission signal; and transmission processing means for setting power of the transmission signal When the transmission processing unit sets the power of the transmission signal, a calculation unit that calculates a power difference between the power and the power set by the transmission processing unit immediately before the power is set; and the calculation unit When the calculated power difference exceeds a variation threshold, the variable amplification means is controlled to make the level of the local signal higher than a predetermined level, and the power difference is the variation threshold. If not exceeded and a control means for the level of the local signal to the predetermined level.

  The noise processing method of the present invention includes a receiving means for outputting a received signal received using an antenna means, a generating means for generating a local signal mixed with the received signal, and a variable capable of changing the level of the local signal. Amplifying means; mixing means for mixing the local signal and the reception signal to generate a reception signal for demodulation; transmission means for transmitting a transmission signal; and transmission processing means for setting power of the transmission signal A method of processing noise in a wireless device, comprising: when the transmission processing unit sets the power of the transmission signal, the power and the power set by the transmission processing unit immediately before the power is set. A calculation step of calculating a power difference; and if the power difference calculated in the calculation step exceeds a fluctuation amount threshold value, the variable amplification means is controlled to control the local signal. The bell was higher than a predetermined level, when the power difference does not exceed the variation threshold and a control step of the level of the local signal to the predetermined level.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to suppress degradation of the receiving characteristic resulting from the fluctuation | variation of the electric power of a transmission signal.

It is a block diagram which shows the radio | wireless apparatus in 1st Embodiment of this invention. It is a flowchart which shows the noise processing method in 1st Embodiment. It is a flowchart which shows the noise processing method in 2nd Embodiment. It is a flowchart which shows the noise processing method in 3rd Embodiment. It is a flowchart which shows the noise processing method in 4th Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing a radio apparatus according to the first embodiment of the present invention.

  The wireless device 100 is a wireless communication device used in a communication system that employs WCDMA or LTE. The communication device 100 transmits a transmission signal to the radio base station and demodulates the reception signal. The wireless device 100 is realized by a mobile phone, for example.

  The wireless device 100 includes a signal processing device 1 and an RF (Radio Frequency) device 2. The signal processing unit 1 includes a noise processing unit 1A, a transmission processing unit 17, and a difference calculation unit 18. The noise processing unit 1 </ b> A includes a level control unit 19 and a reception processing unit 20. The RF device 2 includes an RF unit 4 and an RFIC (Radio Frequency Integrated Circuit) unit 5. The RF unit 4 includes an antenna 3, an antenna SW 6, a filter 7, an amplifier 15, and an isolator 16.

  The signal processing unit 1 is a device that performs digital signal processing. The signal processing unit 1 generates a transmission signal addressed to the radio base station and outputs it to the conversion circuit 14. The signal processing unit 1 performs digital signal processing on the received signal.

  The RF device 2 is used for communicating with a radio base station using a radio signal.

  The RFIC unit 5 performs D / A (Digital to Analog) conversion and frequency conversion on the transmission signal generated by the signal processing unit 1. The RFIC unit 5 performs frequency conversion and A / D (Analog to Digital) conversion on the received signal. The RFIC unit 5 includes a transmission unit 5A, an LNA (Low Noise Amplifier) 8, a conversion circuit 9, a buffer amplifier 10, and an Rx oscillator 11.

  Transmitter 5A can generally be referred to as a transmission means.

  The transmission unit 5 </ b> A transmits a transmission signal using the RF unit 4. The transmission unit 5A includes a Tx oscillator 12, a buffer amplifier 13, and a modulation circuit 14.

  The Tx oscillator 12 generates a local signal that is mixed with the transmission signal. The Tx oscillator 12 is realized by, for example, a PLL (Phase-locked loop) synthesizer. The Tx oscillator 12 outputs the local signal to the buffer amplifier 13.

  The buffer amplifier 13 amplifies the local signal output from the Rx oscillator 11 and outputs the amplified local signal to the conversion circuit 14.

  When the conversion circuit 14 receives the amplified local signal from the buffer amplifier 13 and receives the transmission signal from the signal processing unit 1, the conversion circuit 14 mixes the amplified local signal and the transmission signal. The conversion circuit 9 outputs the mixed transmission signal to the amplifier 15.

  The RF unit 4 can be generally referred to as antenna means.

  The RF unit 4 outputs a transmission signal as a radio signal via the antenna 3 to the radio base station. Further, the RF unit 4 outputs the radio signal output from the antenna 3 to the LNA 8.

  When receiving the transmission signal from the conversion circuit 14, the amplifier 15 amplifies the power of the transmission signal and outputs the amplified transmission signal to the isolator 16. The amplifier 15 is a PA (Power Amplifier) that can amplify a transmission signal to high power.

  The isolator 16 is used to suppress the backflow of the transmission signal output from the amplifier 15.

  The filter 7 is a duplexer that separates a transmission signal and a reception signal.

  The antenna SW6 switches the antenna 3 from the transmitting antenna to the receiving antenna, or switches the antenna 3 from the receiving antenna to the transmitting antenna.

  The antenna 3 is used for transmitting and receiving a radio signal between the radio apparatus 100 and the radio base station.

  LNA 8 can be generally referred to as receiving means.

  The LNA 8 receives a radio signal using the RF unit 4 and amplifies the received radio signal. The LNA 8 outputs the amplified radio signal to the conversion circuit 9 as a received signal. The LNA 8 is an amplifier that can amplify a received radio signal while suppressing noise.

  Rx oscillator 11 can generally be referred to as generating means.

  The Rx oscillator 11 generates a local signal for reception mixed with the reception signal. The Rx oscillator 11 is realized by, for example, a PLL (Phase-locked loop) synthesizer. The Rx oscillator 11 outputs a local signal for reception to the buffer amplifier 10.

  Buffer amplifier 10 can be generally referred to as variable amplification means.

  The buffer amplifier 10 is a buffer that amplifies the local signal output from the Rx oscillator 11 and can change the level of the local signal. The buffer amplifier 10 outputs the amplified local signal to the conversion circuit 9.

  Conversion circuit 9 can generally be referred to as mixing means.

  When receiving the amplified local signal from the buffer amplifier 10 and receiving the reception signal from the LNA 8, the conversion circuit 9 mixes the amplified local signal and the reception signal to generate a reception signal for demodulation. The conversion circuit 9 outputs a reception signal for demodulation to the reception processing unit 20.

  Transmission processing unit 17 can be generally referred to as transmission processing means.

  The transmission processing unit 17 performs a predetermined modulation process on the data signal indicating communication information addressed to the radio base station to generate a transmission signal having a predetermined frequency bandwidth. Further, the transmission processing unit 17 generates modulation information indicating the modulation processing performed on the transmission signal and bandwidth information indicating the frequency bandwidth of the transmission signal in the transmission signal. The transmission processing unit 17 sets the power of the transmission signal and outputs the transmission signal after setting.

  The transmission processing unit 17 performs modulation processing of QPSK (Quadrature Phase Shift Keying) or 64 QAM (Quadrature Amplitude Modulation) on the data signal.

  Further, the transmission processing unit 17 generates a burst signal in which the power of the transmission signal changes intermittently. For example, when communicating with a radio base station using PRACH (Physical Random Access Channel), the transmission processing unit 17 requests the radio base station to allocate a communication channel, so that a slot interval of a predetermined period is used. Every time, the binary power of the burst signal is set. For example, after setting the transmission power for outputting the radio signal, the transmission processing unit 17 sets the stop power for stopping the transmission.

  Further, the transmission processing unit 17 controls the power of the transmission signal according to the radio wave environment between the wireless base station and the wireless device 100. For example, the transmission processing unit 17 receives the reference signal from the radio base station, and sets the power of the transmission signal to be higher stepwise as the level of the reference signal becomes lower. For example, the power of the transmission signal is set within a range of +26 dBm to -56 dBm.

  The transmission processing unit 17 outputs a transmission signal including power information indicating the power of the set transmission signal to the transmission unit 5A and the difference calculation unit 18.

  Difference calculation unit 18 can be generally referred to as calculation means.

  The difference calculation unit 18 calculates a power difference Pdiff between the power P set by the transmission processing unit 17 and the previous power Ppre set by the transmission processing unit 17 immediately before the power P is set.

  In the present embodiment, when receiving the power information included in the transmission signal, the difference calculating unit 18 holds the power value Ppre indicated by the power information. After that, when receiving the power information, the difference calculation unit 18 subtracts the held power value Ppre from the power P indicated by the power information, and calculates the subtracted difference as the power difference Pdiff. For example, the difference calculation unit 18 calculates a power difference Pdiff for each slot interval, and outputs the power difference Pdiff to the level control unit 19 in the noise processing unit 1A every time the power difference Pdiff is calculated.

  Noise processing unit 1A can be generally referred to as control means.

  When the power difference calculated by the difference calculation unit 18 exceeds the fluctuation amount threshold, the noise processing unit 1A controls the buffer amplifier 10 to make the level of the local signal for reception higher than the normal level. On the other hand, when the power difference does not exceed the fluctuation amount threshold, the noise processing unit 1A sets the level of the local signal for reception to a normal level.

  Level control unit 19 can be generally referred to as level control means.

  The level control unit 19 holds a variation amount threshold value for determining whether or not the reception characteristic is deteriorated due to the variation in the power of the transmission signal. When the level controller 19 receives the power difference Pdiff from the difference calculator 18, the level controller 19 checks whether the power difference Pdiff exceeds the fluctuation amount threshold.

  When the power difference Pdiff exceeds the fluctuation amount threshold value, the level control unit 19 controls the buffer amplifier 10 to make the level of the local signal for reception higher than a predetermined normal level. That is, the level control unit 19 increases the amplification gain of the buffer amplifier 10 that amplifies the local signal for reception when the power difference Pdiff exceeds the fluctuation amount threshold value. The normal level may be called a predetermined level.

  On the other hand, when the power difference Pdiff does not exceed the fluctuation amount threshold, the level control unit 19 controls the buffer amplifier 10 to set the level of the local signal for reception to the normal level. For example, if the power difference Pdiff received from the difference calculation unit 18 after increasing the level of the local signal does not exceed the fluctuation amount threshold value, the level control unit 19 returns the level of the local signal for reception to the normal level. .

  Reception processing unit 20 can be generally referred to as reception processing means.

  When receiving a demodulation reception signal from the conversion circuit 9, the reception processing unit 20 performs digital signal processing for demodulating the reception signal. For example, the reception processing unit 20 demodulates a reception signal that has been subjected to QPSK or 64QAM modulation processing at a radio base station.

  The reception processing unit 20 specifies a modulation process performed on a demodulation reception signal among the QPSK or 64QAM modulation processes. For example, when receiving the reception signal including the modulation information indicating the modulation processing, the reception processing unit 20 performs the modulation processing indicated by the modulation information included in the reception signal as the modulation processing applied to the reception signal for demodulation. Identify.

  In addition, the reception processing unit 20 specifies the frequency bandwidth of the demodulation reception signal. For example, in a communication system employing LTE, any one frequency band of 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz is selected according to the propagation state of radio waves between the wireless device 100 and the wireless base station. A width radio signal is used. In this case, when receiving the reception signal including the bandwidth information indicating the frequency bandwidth, the reception processing unit 20 converts the frequency bandwidth indicated by the bandwidth information included in the reception signal to the frequency of the demodulation reception signal. Identified as bandwidth.

  Further, the reception processing unit 20 performs digital signal processing and averages the received signals at the slot intervals digitized to calculate an RSSI (Received Signal Strength Indication) value. The RSSI value is a numerical value of the strength of the received signal. The RSSI value is also called reception strength.

  When the received signal is demodulated, the reception processing unit 20 outputs the demodulated received signal to a CPU (Central Processing Unit) device. For example, when receiving a reception signal indicating a connection instruction from a radio base station, the CPU device executes a connection process according to the connection instruction indicated by the reception signal.

  FIG. 2 is a flowchart illustrating a processing procedure example of the noise processing method of the wireless device 100.

  First, the transmission processing unit 17 sets the power of the transmission signal to the power P (step S11). The difference calculation unit 18 calculates a power difference Pdiff between the power P set by the transmission processing unit 17 and the previous power Ppre set immediately before setting the power P (step S12). In the present embodiment, the difference calculation unit 18 calculates a power difference Pdiff obtained by subtracting the previous power Ppre from the power P set by the transmission processing unit 17.

  When the difference calculation unit 18 calculates the power difference Pdiff, the level control unit 19 compares the power difference Pdiff with the fluctuation amount threshold value (step S13). When the power difference Pdiff exceeds the fluctuation amount threshold value, the fluctuation of the power of the transmission signal is large, so that the fluctuation of the current of the transmission signal is large and the coupling (interference) between the transmission signal and the reception signal is large.

  Therefore, when the power difference Pdiff exceeds the fluctuation amount threshold, the level control unit 19 controls the buffer amplifier 10 so that the level of the local signal for reception is higher than the normal level. The amplification gain is increased (step S15). Therefore, the radio apparatus 100 improves the C / N ratio (carrier-to-noise ratio) of the reception signal for demodulation and increases the noise resistance of the reception signal, thereby receiving the transmission signal due to coupling from the signal line. It is possible to suppress deterioration of signal reception sensitivity.

  On the other hand, when the power difference Pdiff is equal to or less than the fluctuation amount threshold value, the level control unit 19 controls the buffer amplifier 10 to set the level of the local signal for reception to a normal level (step S14).

  And if the process of step S14 or S15 is performed, the radio | wireless apparatus 100 will complete | finish the process sequence of a noise processing method.

  According to the first embodiment, the radio apparatus 100 receives a radio signal using the RF unit 4, generates an LNA 8 that outputs the radio signal as a reception signal, and a reception local signal mixed with the reception signal. An Rx oscillator 11, a buffer amplifier 10 capable of changing the level of the local signal for reception, and a conversion circuit 9 that mixes the local signal for reception and the reception signal to generate a reception signal for demodulation. . Furthermore, the wireless device 100 includes a transmission unit 5A that transmits a transmission signal using the RF unit 4, and a transmission processing unit 17 that sets the power of the transmission signal. In the wireless device 100, the difference calculation unit 18 calculates a power difference between the power set by the transmission processing unit 17 and the power set by the transmission processing unit 17 immediately before the power is set. When the power difference exceeds the fluctuation amount threshold, the level control unit 19 controls the buffer amplifier 10 to make the level of the local signal for reception higher than the normal level. When the power difference does not exceed the fluctuation amount threshold, the level control unit 19 sets the level of the local signal for reception to a normal level.

  In general, in radio apparatus 100 in which a signal line of a transmission signal and a signal line of a reception signal are arranged close to each other, a magnetic field is generated due to a sudden power fluctuation of the transmission signal, and noise is generated in the reception signal due to the magnetic field. May be superimposed. When noise is superimposed on the received signal, the C / N of the received signal is lowered, the BER (Bit Error Rate) is deteriorated, and the reception characteristics are deteriorated. As an example in which the power of the transmission signal fluctuates rapidly, for example, when the wireless device 100 transmits a burst signal, or a function of setting the power of the transmission signal to be higher stepwise as the communication environment with the wireless base station deteriorates It is conceivable that the radio apparatus 100 having the communication environment becomes worse and the power of the transmission signal is set high.

  For this reason, the radio apparatus 100 calculates the power difference of the transmission signal, and increases the amplification gain of the buffer amplifier 10 that amplifies the local signal for reception when the power difference exceeds the fluctuation amount threshold value. Therefore, radio apparatus 100 can sufficiently secure the C / N of the reception signal for demodulation even when noise is superimposed on the reception signal due to a sudden power fluctuation of the transmission signal, and reception characteristics can be secured. It becomes possible to avoid degradation of the.

  Next, a radio apparatus according to the second embodiment will be described. Note that the basic configuration of the wireless device of the second embodiment is the same as that of the wireless device 100 of the first embodiment.

  In the wireless device, even if the C / N ratio of the received signal is deteriorated due to the rapid fluctuation of the power of the transmission signal, if the RSSI value measured by the reception processing unit 20 is sufficiently high, the reception characteristic of the received signal is not so much. Does not deteriorate.

  Therefore, in the second embodiment, the level control unit 19 controls the level of the local signal for reception using the power difference and the RSSI value. Here, the level control unit 19 holds in advance an intensity threshold value for determining whether or not there is a possibility of deterioration in reception characteristics.

  FIG. 3 is a flowchart illustrating a noise processing method according to the second embodiment.

  First, the transmission processing unit 17 sets the power of the transmission signal to the power P (step S21). The difference calculation unit 18 calculates a power difference Pdiff obtained by subtracting the previous power Ppre from the power P set by the transmission processing unit 17 (step S22).

  When the difference calculation unit 18 calculates the power difference Pdiff, the level control unit 19 compares the power difference Pdiff with the fluctuation amount threshold value (step S23). If the power difference Pdiff is equal to or less than the fluctuation amount threshold value, the level control unit 19 controls the buffer amplifier 10 to set the level of the local signal for reception to a normal level (step S27).

  On the other hand, when the power difference Pdiff exceeds the fluctuation amount threshold value, the reception processing unit 20 measures the RSSI value of the demodulation reception signal (step S24). The reception processing unit 20 outputs the RSSI value to the level control unit 19.

  When the level control unit 19 receives the RSSI value from the reception processing unit 20, the level control unit 19 compares the RSSI value with the intensity threshold value (step S25). When the RSSI value is lower than the strength threshold, the level of the received signal is low, and thus the received signal is considered to have low resistance to noise superimposed due to fluctuations in the power of the transmitted signal.

  Therefore, when the RSSI value is lower than the intensity threshold, the level control unit 19 controls the buffer amplifier 10 to make the level of the local signal for reception higher than the normal level (step S26). Therefore, radio apparatus 100 can suppress deterioration in reception sensitivity by improving the C / N ratio of the received signal for demodulation and increasing the noise resistance of the received signal.

  On the other hand, when the RSSI value exceeds the intensity threshold, the level control unit 19 controls the buffer amplifier 10 to set the level of the local signal for reception to a normal level (step S27).

  When the process of step S26 or S27 ends, the wireless device 100 ends the processing procedure of the noise processing method.

  According to the second embodiment, the noise processing unit 20 measures the RSSI value of the reception signal for demodulation, and outputs the output from the buffer 10 by controlling the buffer amplifier 10 when the RSSI value does not exceed the intensity threshold value. The level of the received local signal is set to a normal level.

  Therefore, even when the power difference exceeds the fluctuation amount threshold, the wireless device of the second embodiment sets the level of the local signal for reception to the normal level when the RSSI value of the reception signal exceeds the strength threshold. To level. For this reason, when demodulating a received signal whose reception characteristics hardly deteriorate even if the C / N ratio of the demodulated received signal deteriorates due to a sudden fluctuation in the power of the transmitted signal, the wireless device transmits the local signal for reception. Maintain the normal level without increasing the level. Therefore, the wireless device can suppress an increase in power consumption of the buffer amplifier 10 due to an increase in the level of the local signal for reception.

  Next, a radio apparatus according to the third embodiment will be described. The basic configuration of the wireless device of the third embodiment is the same as that of the wireless device of the second embodiment.

  In a communication system that employs WCDMA or LTE, one of the modulation schemes of QPSK and 64QAM is set according to the propagation state of radio waves between the radio apparatus and the radio base station. QPSK can transmit 4-level (2-bit) information in one clock. On the other hand, 64QAM can transmit 64 values (6 bits) of information in one clock. 64QAM has a higher modulation density than QPSK. For this reason, the reception characteristics of the received signal subjected to the 64QAM modulation process are more likely to deteriorate than QPSK.

  Therefore, the level control unit 19 of the third embodiment holds in advance an RSSI threshold corresponding to the modulation processing of the modulation scheme for each modulation scheme, and is output from the buffer amplifier 10 using the RSSI threshold for each modulation scheme. Controls the level of local signals for reception. Note that the RSSI threshold corresponding to the modulation processing may be referred to as a reception threshold specific threshold.

  In the third embodiment, for example, the RSSI threshold value of QPSK (hereinafter referred to as “PSK threshold value”) is set to −90 dBm, and the RSSI threshold value of 64 QAM (hereinafter referred to as “QAM threshold value”) is set to −70 dBm. . This is because 64QAM reception characteristics are more likely to deteriorate than QPSK, and it is necessary to increase the 64QAM RSSI threshold.

  FIG. 4 is a flowchart illustrating a noise processing method according to the third embodiment.

  First, the transmission processing unit 17 sets a 64QAM or QPSK modulation scheme, and performs a modulation process corresponding to the modulation scheme on the data signal to generate a transmission signal. Further, the transmission processing unit 17 sets the power of the transmission signal to the power P, and outputs the set transmission signal to the transmission unit 5A (step S31). The difference calculation unit 18 calculates a power difference Pdiff obtained by subtracting the previous power Ppre from the power P set by the transmission processing unit 17 (step S32).

  When the difference calculation unit 18 calculates the power difference Pdiff, the level control unit 19 compares the power difference Pdiff with the fluctuation amount threshold value (step S33). When the power difference Pdiff is equal to or less than the fluctuation amount threshold value, the level control unit 19 controls the buffer amplifier 10 to set the level of the local signal for reception to a normal level (step S39).

  On the other hand, when the power difference Pdiff exceeds the fluctuation amount threshold value, the reception processing unit 20 measures the RSSI value of the demodulation reception signal (step S34). In addition, the reception processing unit 20 identifies the modulation process performed on the received signal, and generates modulation information indicating the modulation process. The reception processing unit 20 outputs the RSSI value and the modulation information to the level control unit 19.

  When receiving the modulation information indicating the modulation process, the level control unit 19 determines whether the modulation process indicated by the modulation information is a 64QAM modulation method (step S35).

  When the modulation process indicated by the modulation information is 64QAM, the level control unit 19 specifies an RSSI QAM threshold (−70 dBm) corresponding to the 64QAM modulation process. The level control unit 19 receives the RSSI value from the reception processing unit 20, and compares the RSSI value with the QAM threshold (step S36). When the RSSI value is equal to or greater than the QAM threshold, the level control unit 19 sets the level of the local signal for reception output from the buffer amplifier 10 to a normal level (step S40).

  On the other hand, when the RSSI value is less than the QAM threshold, the level control unit 19 raises the level of the local signal for reception output from the buffer amplifier 10 above the normal level (step S38). Therefore, radio apparatus 100 can suppress deterioration in reception sensitivity by improving the C / N ratio of the received signal for demodulation and increasing the noise resistance of the received signal.

  Further, when the modulation process indicated by the modulation information is QPSK, the level control unit 19 specifies an RSSI PSK threshold (−90 dBm) corresponding to the QPSK modulation process. Then, the level control unit 19 compares the RSSI value with the PSK threshold value (step S37). When the RSSI value is equal to or greater than the PSK threshold, the level control unit 19 sets the level of the local signal for reception output from the buffer amplifier 10 to a normal level (step S39).

  On the other hand, when the RSSI value is less than the PSK threshold, the level control unit 19 raises the level of the local signal for reception output from the buffer amplifier 10 above the normal level (step S38).

  According to the third embodiment, the transmission processing unit 17 performs a 64QAM or QPSK modulation process on the data signal to generate a transmission signal, and outputs the transmission signal to the transmission unit 5A. In addition, the reception processing unit 17 specifies a modulation process performed on the reception signal for demodulation. Further, the level control unit 19 holds an RSSI threshold value corresponding to 64QAM and QPSK modulation processing. When the power difference exceeds the fluctuation amount threshold value, the level control unit 19 sets the local signal level to the normal level when the RSSI value of the received signal exceeds the threshold value corresponding to the modulation processing specified by the reception processing unit 20. Higher than.

  For this reason, the radio apparatus according to the third embodiment specifies a threshold value suitable for the modulation process applied to the received signal, and if the RSSI value is larger than the threshold value, the radio apparatus for reception output from the buffer amplifier 10 The local signal level is maintained at a normal level without being increased. Therefore, the radio apparatus can control the level of the local signal for reception suitable for each modulation process applied to the received signal, and can reduce unnecessary level control of the local signal for reception. It becomes. Therefore, in the radio apparatus according to the third embodiment, it is possible to further reduce the power consumption of the buffer amplifier 10 than in the second embodiment.

  Next, the radio | wireless apparatus of 4th Embodiment is demonstrated. The basic configuration of the wireless device of the fourth embodiment is the same as that of the wireless device of the second embodiment.

  In a communication system employing LTE, one of the frequency bandwidths of 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz is selected according to the propagation state of radio waves between the wireless device and the wireless base station. A transmission signal is transmitted. As the received signal has a wider frequency bandwidth, the C / N ratio of the received signal required for demodulation increases. That is, the RSSI value required for demodulation increases as the received signal has a wider frequency bandwidth.

  Therefore, the level control unit 19 according to the fourth embodiment holds an RSSI threshold corresponding to the frequency bandwidth in advance for each frequency bandwidth of the received signal, and outputs from the buffer amplifier 10 using the RSSI threshold for each frequency bandwidth. Control the level of the local signal for reception. Note that the RSSI threshold corresponding to the frequency bandwidth may be referred to as a predetermined threshold of received intensity.

  First, the transmission processing unit 17 sets the frequency bandwidth of the transmission signal to any one of a plurality of frequency bandwidths. Further, the transmission processing unit 17 sets the power of the transmission signal to the power P, and outputs a transmission signal having a transmission frequency bandwidth to the transmission unit 5A (step S41). The difference calculation unit 18 calculates a power difference Pdiff obtained by subtracting the previous power Ppre from the power P set by the transmission processing unit 17 (step S42).

  When the difference calculation unit 18 calculates the power difference Pdiff, the level control unit 19 compares the power difference Pdiff and the fluctuation amount threshold value (step S43). If the power difference Pdiff is equal to or less than the fluctuation amount threshold, the level control unit 19 sets the level of the local signal for reception output from the buffer amplifier 10 to a normal level (step S44).

  On the other hand, when the power difference Pdiff exceeds the fluctuation amount threshold value, the reception processing unit 20 measures the RSSI value of the demodulation reception signal (step S45). In addition, when receiving a reception signal including band information indicating the frequency bandwidth, the reception processing unit 20 specifies the frequency bandwidth of the reception signal and generates bandwidth information indicating the frequency bandwidth. The reception processing unit 20 outputs the RSSI value and the bandwidth information to the level control unit 19.

  When the level control unit 19 receives the bandwidth information indicating the frequency bandwidth of the received signal, the level control unit 19 specifies a corresponding threshold value of RSSI corresponding to the frequency bandwidth indicated by the bandwidth information (step S46). Then, the level control unit 19 receives the RSSI value from the reception processing unit 20, and compares the RSSI value with the corresponding threshold value (step S47). If the RSSI value is greater than or equal to the corresponding threshold, the level control unit 19 sets the level of the local signal for reception output from the buffer amplifier 10 to a normal level (step S48).

  On the other hand, when the RSSI value is less than the corresponding threshold value, the level control unit 19 raises the level of the local signal for reception output from the buffer amplifier 10 higher than the normal level (step S44). Therefore, radio apparatus 100 suppresses deterioration in reception sensitivity due to coupling of the transmission signal from the signal line by improving the C / N ratio of the reception signal for demodulation and enhancing the noise resistance of the reception signal. It becomes possible.

  According to the fourth embodiment, the transmission processing unit 17 outputs a transmission signal having a transmission frequency bandwidth selected from among a plurality of frequency bandwidths to the transmission unit 51A. Further, the level control unit 19 holds an RSSI threshold corresponding to a plurality of frequency bandwidths. The reception processing unit 20 measures the RSSI value of the reception signal for demodulation and further specifies the frequency bandwidth of the reception signal. Then, the level control unit 19 sets the level of the local signal for reception output from the buffer amplifier 10 when the RSSI value of the reception signal exceeds the threshold corresponding to the frequency bandwidth specified by the reception processing unit 20 to the normal level. To.

  For this reason, when the RSSI value of the received signal is larger than the RSSI threshold suitable for the frequency bandwidth of the received signal, the wireless device of the fourth embodiment is configured to receive the local signal for reception output from the buffer amplifier 10. Maintain the normal level without increasing the level. Therefore, the radio apparatus can control the level of the local signal suitable for each frequency bandwidth, and can suppress the power consumption of the buffer amplifier 10.

  In each embodiment described above, the illustrated configuration is merely an example, and the present invention is not limited to the configuration.

DESCRIPTION OF SYMBOLS 100 Radio | wireless apparatus 1 Signal processing part 1A Noise processing part 2 RF apparatus 3 Antenna 4 RF part 5 RFIC part 5A Transmitting part 6 Antenna SW
7 Filter 8 LNA
9, 14 Conversion circuit 10, 13 Buffer amplifier 11 Rx oscillator 12 Tx oscillator 15 Amplifier 16 Isolator 17 Transmission processing unit 18 Difference calculation unit 19 Level control unit 20 Reception processing unit

Claims (6)

Receiving means for outputting a received signal received using the antenna means;
Generating means for generating a local signal mixed with the received signal;
Variable amplification means capable of changing the level of the local signal;
Mixing means for mixing the local signal and the received signal to generate a received signal for demodulation;
A transmission means for transmitting a transmission signal;
Transmission processing means for setting the power of the transmission signal;
When the transmission processing unit sets the power of the transmission signal, a calculation unit that calculates a power difference between the power and the power set by the transmission processing unit immediately before the power is set;
When the power difference calculated by the calculating means exceeds a fluctuation amount threshold value, the variable amplification means is controlled to make the level of the local signal higher than a predetermined level, and the power difference exceeds the fluctuation amount threshold value. Control means for setting the level of the local signal to the predetermined level when there is not. The wireless device according to claim 1, wherein
The control device measures a reception intensity of the demodulation reception signal, and sets the local signal level to the predetermined level when the reception intensity exceeds an intensity threshold. The wireless device according to claim 2, wherein
The transmission processing means generates a transmission signal by performing predetermined modulation processing on a data signal, and outputs the transmission signal to the transmission means,
The control means includes
Reception processing means for specifying the modulation processing applied to the received signal;
And a level control unit that sets the level of the local signal to the predetermined level when the reception intensity of the received signal exceeds a specific threshold value corresponding to the modulation process specified by the reception processing unit. The wireless device according to claim 2 or 3,
The transmission processing means outputs the transmission signal having a predetermined frequency bandwidth to the transmission means,
The control means includes
Reception processing means for specifying a frequency bandwidth of the received signal;
A radio apparatus comprising: a level control unit configured to set the level of the local signal to the predetermined level when the reception intensity of the received signal exceeds a predetermined threshold corresponding to the frequency bandwidth specified by the reception processing unit. . Receiving means for outputting a received signal received using an antenna means; generating means for generating a local signal mixed with the received signal; variable amplifying means capable of changing a level of the local signal; and the local signal; Noise processing in a radio apparatus comprising: mixing means for mixing the reception signals to generate a reception signal for demodulation; transmission means for transmitting a transmission signal; and transmission processing means for setting power of the transmission signal A method,
When the transmission processing means sets the power of the transmission signal, a calculation step of calculating a power difference between the power and the power set by the transmission processing means immediately before the power is set;
When the power difference calculated in the calculating step exceeds a fluctuation amount threshold value, the variable amplification means is controlled to make the level of the local signal higher than a predetermined level, and the power difference becomes less than the fluctuation amount threshold value. And a control step of setting the level of the local signal to the predetermined level when not exceeding. The noise processing method according to claim 5,
In the control step, the reception intensity of the demodulation reception signal is measured, and when the reception intensity exceeds an intensity threshold, the level of the local signal is set to the predetermined level.

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