JP2006287713A - Receiver, control method thereof, communication controller and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a receiver capable of demodulating a desired signal with high sensitivity and reducing an influence of a jamming signal, and to provide a control method thereof, a communication controller and electronic equipment. <P>SOLUTION: The receiver 10 includes an amplification part 20 which amplifies a received signal including the desired signal and the jamming signal, a receiving intensity detection part 30 which detects a receiving intensity level of the desired signal amplified by the amplification part 20 and a demodulation part 40 which generates a demodulation signal formed by demodulating the received signal amplified by the amplification part 20. The receiver 10 adjusts gain of the amplification part 20 on the basis of the receiving intensity level and a judgment result obtained by judging quality of the demodulation signal based on a reference signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a receiving apparatus, a control method thereof, a communication controller, and an electronic device.

  In recent years, digitalization of wireless communication has progressed, and information such as voice, images, and data can be exchanged between portable electronic devices. As one of such wireless communications, Bluetooth (registered trademark) has been formulated as a standard for wireless connection between electronic devices such as mobile terminals such as mobile phones, personal computers, and AV devices.

  In the standard of Bluetooth (registered trademark), communication is performed using a 2.4 GHz band called an ISM band (Industrial Science and Medical band) as a frequency band. This ISM band is a frequency band secured in common throughout the world for industrial, scientific and medical purposes, and can be used almost freely throughout the world. For this reason, applications of electronic devices using the ISM band are diversified, and are used for electromagnetic wave radiation frequency of a microwave oven, use frequency of a wireless LAN device of the IEEE 802.11 standard, and the like. Therefore, interference signals tend to increase when a desired signal is received. In such a wireless communication receiver, it is important how to reduce the influence of the interference signal when extracting the desired signal from the received signal. It has become a challenge.

Not only such Bluetooth (registered trademark) but also a wireless communication receiving apparatus in which the influence of interference signals tends to increase, the received signal is amplified by an amplifier circuit. In this case, the gain of the amplifier circuit is adjusted based on a reception intensity level called RSSI (Received Signal Strength Indicator) proportional to the reception power, if necessary. For example, Patent Document 1 discloses a technique for performing balanced transmission power control and improvement of an IM (Inter-Modulation) problem using RSSI in a code division multiple access (CDAM) receiver. Has been.
JP-A-9-205332

  By the way, it is desirable that the receiving apparatus can demodulate the desired signal with high sensitivity. On the other hand, it is desirable to minimize the influence of interference signals in the receiving apparatus. Therefore, in the receiving apparatus, it is necessary to accurately control the gain of the amplifier circuit that amplifies the received signal. For example, when the gain of the amplifier circuit is increased, generally the SN ratio of the received signal including the desired signal (hereinafter also referred to as reception quality and reception data quality) is improved, and reception sensitivity is improved. However, in an environment in which many interference signals are included, not only the desired signal included in the received signal but also the interference signal is amplified. For example, in the IM problem, when the gain of the amplifier circuit increases, the magnitude of the desired signal increases proportionally, but the magnitude of the interference signal increases proportionally by a factor of three. This means that a slight gain error greatly affects the interference signal. Therefore, it is necessary to accurately control the gain of the amplifier circuit.

  However, it is known that the detection accuracy of the RSSI detection circuit varies due to variations in the bias circuit constituting the receiving device, and the RSSI varies by 6 dB or more with respect to the same input level. Therefore, when the gain of the amplifier circuit is adjusted based on such RSSI, a large variation occurs in the level of the interference signal after being amplified by the amplifier circuit, resulting in variation in the interference suppression characteristics as a receiver. If accuracy is not achieved, it is necessary to make a redundant design such as increasing a margin from the standard value, which has a demerit of increasing current consumption.

  It is also conceivable to detect the magnitude of the interference signal using RSSI and adjust the gain of the amplifier circuit based on the detection result. However, the gain of the amplifier circuit is adjusted based on whether the RSSI exceeds a predetermined level based on the prediction, and it is necessary to set a table corresponding to this prediction in advance. Therefore, in addition to the difficulty of prediction, it is necessary to provide a table, and the accuracy of gain control cannot be improved, or the cost is increased.

  The present invention has been made in view of the technical problems as described above, and an object of the present invention is to provide a receiving apparatus capable of demodulating a desired signal with high sensitivity and reducing the influence of an interfering signal, and a control method thereof. It is to provide a communication controller and an electronic device.

In order to solve the above problems, the present invention
A receiving device for receiving a received signal including a desired signal and an interference signal,
An amplifying unit for amplifying the received signal;
A reception intensity detection unit for detecting a reception intensity level of the reception signal amplified by the amplification unit;
A demodulation unit that generates a demodulated signal obtained by demodulating the reception signal amplified by the amplification unit,
The present invention relates to a receiving apparatus that adjusts the gain of the amplifying unit based on the reception intensity level and a determination result obtained by determining whether the quality of the demodulated signal is good or not based on a reference signal.

  According to the present invention, the gain of the amplifying unit is adjusted using not only the reception intensity level but also the determination result of the quality of the demodulated signal, so that the influence of the interference signal included in the received signal is increased. This makes it possible to suppress a decrease in reception sensitivity.

In the receiving device according to the present invention,
When the quality of the demodulated signal is lower than the first reference quality level and the reception intensity level is higher than the first reference intensity level, the gain of the amplification unit can be adjusted to be small.

  In the present invention, when the determination result of the quality of the demodulated signal is negative, the cause may be that the reception intensity level is low or the level of the interference signal is low. Therefore, according to the present invention, the reception sensitivity is lowered by reducing the gain of the amplification unit, but the level of the interference signal can be lowered to reduce the influence of the interference signal. Therefore, the quality of the demodulated signal can be improved. Accordingly, it is possible to provide a receiving apparatus that can demodulate a desired signal with high sensitivity and reduce the influence of an interference signal.

In the receiving device according to the present invention,
When the quality of the demodulated signal is lower than the second reference quality level and the reception intensity level is lower than the second reference intensity level, the gain of the amplifying unit can be adjusted to be increased.

  In the present invention, when the determination result of the quality of the demodulated signal is negative, it is conceivable that the reception intensity level is low as the cause. This is because the influence of the disturbing signal included in the received signal is small because the reception intensity level itself is small. Therefore, according to the present invention, by increasing the gain of the amplifying unit, the level of the disturbing signal is increased and the influence of the disturbing signal is increased, but the level of the desired signal is also increased and the quality of the demodulated signal is improved. Will be able to. Therefore, the quality of the demodulated signal can be improved. Therefore, it is possible to provide a receiving apparatus that can demodulate a desired signal with high sensitivity and reduce the influence of an interference signal.

In the receiving device according to the present invention,
The amplification unit is
A first amplifier that amplifies the input signal with a first gain;
A second amplifier for amplifying the input signal with a second gain lower than the first gain;
When the operation mode of the reception device that amplifies the reception signal by the first amplifier is the first mode, and the operation mode of the reception device that amplifies the reception signal by the second amplifier is the second mode In addition,
The gain of the amplifying unit can be adjusted by switching from one of the first and second modes to the other mode based on the reception intensity level and the determination result.

In the receiving device according to the present invention,
In the first mode, when the quality of the demodulated signal is lower than the first reference quality level and the reception strength level is higher than the first reference strength level, the first mode is changed to the second mode. Can be switched.

  In the present invention, when it is determined that the quality of the demodulated signal is good or bad, in the first mode, the cause may be that the reception intensity level is low or the level of the interference signal is high. . Therefore, according to the present invention, the level of the interference signal can be lowered by switching to the second mode for lowering the gain of the amplifying unit, and as a result, the quality of the demodulated signal can be improved. Therefore, it is possible to provide a receiving apparatus that can demodulate a desired signal with high sensitivity and reduce the influence of an interference signal.

In the receiving device according to the present invention,
In the second mode, when the quality of the demodulated signal is lower than the second reference quality level and the reception strength level is lower than the second reference strength level, the second mode is changed to the first mode. Can be switched.

  In the present invention, when it is determined that the quality of the demodulated signal is good or bad, in the second mode, the cause may be that the reception intensity level is low. Therefore, according to the present invention, the reception strength level can be increased by switching to the first mode for increasing the gain of the amplification unit. Therefore, when the reception strength level is smaller than a given level, the amplification unit Increasing the gain results in better demodulated signal quality. Therefore, it is possible to provide a receiving apparatus that can demodulate a desired signal with high sensitivity and reduce the influence of an interference signal.

In the receiving device according to the present invention,
The determination result is
It may be a result of determining the quality of the demodulated signal by comparing the identification code or access code included in the demodulated signal with a given reference code.

In the receiving device according to the present invention,
The determination result is
It may be a result of determining the quality of the demodulated signal by comparing the bit error rate of the demodulated signal with a given reference bit error rate.

In the receiving device according to the present invention,
The determination result is
It may be a result of determining the quality of the demodulated signal by comparing the packet error rate obtained as a result of analyzing the demodulated signal with a given reference packet error rate.

  According to any one of the above inventions, the quality of the demodulated signal can be determined with a simple configuration. Therefore, with a simple configuration, the gain of the amplification unit can be adjusted using this determination result, and a decrease in reception sensitivity can be suppressed while suppressing an increase in the influence of an interference signal included in the reception signal.

In the receiving device according to the present invention,
The reception intensity detection unit
A limiter amplifier for amplifying the received signal and limiting the amplitude to a given level;
The demodulator
An FM (Frequency Modulation) detection circuit that detects a change in frequency of the demodulated signal can be included.

The present invention also provides
A first amplifier that amplifies the input signal with a first gain;
A second amplifier for amplifying the input signal with a second gain lower than the first gain;
A control method of a receiving apparatus that operates in a first mode in which a received signal including a desired signal and an interference signal is amplified by the first amplifier, or in a second mode in which the received signal is amplified by the second amplifier. There,
Amplifying the received signal with the first or second amplifier;
Detecting the received intensity level of the amplified received signal and demodulating the received signal;
Compare the demodulated signal obtained by demodulation and the reference signal to determine the quality of the demodulated signal,
The present invention relates to a control method of a receiving apparatus that switches from one of the first and second modes to the other mode based on the determination result of the quality of the demodulated signal and the reception intensity level.

In the receiving device control method according to the present invention,
In the first mode, when the quality of the demodulated signal is lower than the first reference quality level and the reception strength level is higher than the first reference strength level, the first mode is changed to the second mode. Can be switched.

In the receiving device control method according to the present invention,
In the second mode, when the quality of the demodulated signal is lower than the second reference quality level and the reception strength level is lower than the second reference strength level, the second mode is changed to the first mode. Can be switched.

The present invention also provides
A power amplifying unit for amplifying a transmission signal obtained by modulating transmission data;
The present invention relates to a communication controller including any of the above-described receiving apparatuses.

  According to the present invention, it is possible to provide a communication controller including a receiving device that can demodulate a desired signal with high sensitivity and reduce the influence of an interference signal.

The present invention also provides
A communication controller as described above;
A base for outputting a transmission data to the communication controller, including a quality determination unit that determines the quality of the demodulated signal by comparing reference data and received data corresponding to the demodulated signal from the communication controller It relates to electronic equipment including a band engine.

In the electronic device according to the present invention,
An antenna for transmitting a transmission signal corresponding to the transmission data and receiving a reception signal corresponding to the reception data may be included.

  According to any one of the above-described inventions, it is possible to provide an electronic apparatus including a receiving device that can demodulate a desired signal with high sensitivity and reduce the influence of an interference signal.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. Also, not all of the configurations described below are essential constituent requirements of the present invention.

1. Receiving Device FIG. 1 is a block diagram showing an outline of the configuration of the receiving device in the present embodiment. In FIG. 1, in addition to the receiving apparatus 10 in the present embodiment, a data processing circuit 50 to which a demodulated signal demodulated by the receiving apparatus 10 is input is also shown.

  The receiving device 10 receives a received signal including a desired signal and an interference signal. The receiving apparatus 10 generates a demodulated signal by demodulating the received signal. Therefore, the receiving device 10 includes an amplifying unit 20, a received intensity detecting unit 30, and a demodulating unit 40.

  The amplifying unit 20 amplifies the received signal. That is, the amplification unit 20 amplifies the input signal with the set gain. Therefore, the amplifying unit 20 not only amplifies the amplitude level of the desired signal included in the received signal, but also amplifies the amplitude level of the disturbing signal included in the received signal. The gain of the amplifying unit 20 can be changed based on the gain control signal.

  The reception intensity detection unit 30 detects the reception intensity level of the reception signal (amplified signal) amplified by the amplification unit 20. This received strength level is a level proportional to the electric field strength or power of the received signal. This reception intensity level is output to the data processing circuit 50.

  The demodulator 40 generates a demodulated signal obtained by demodulating the received signal (amplified signal) amplified by the amplifier 20. More specifically, the demodulation unit 40 extracts a desired signal included in the reception signal amplified by the amplification unit 20, performs demodulation processing on the desired signal, and generates a demodulated signal. The demodulated signal is output to the data processing circuit 50.

  The data processing circuit 50 can include a reception quality determination unit 60 and a gain control unit 70. The reception quality determination unit 60 determines the quality of the demodulated signal demodulated by the demodulation unit 40 based on the reference signal, and supplies the determination result to the gain control unit 70. The gain control unit 70 generates a gain control signal for adjusting the gain of the amplification unit 20 based on the reception strength level detected by the reception strength detection unit 30 and the determination result from the reception quality determination unit 60. The gain control signal is supplied to the amplifying unit 20. Therefore, the receiving apparatus 10 adjusts the gain of the amplification unit 20 based on the reception strength level detected by the reception strength detection unit 30 and the determination result of the quality of the demodulated signal demodulated by the demodulation unit 40. be able to. A main signal for adjusting the gain is a signal from the reception quality judgment unit 60. This indirectly represents a reception quality value called SN ratio, bit error rate (BER), or packet error rate (PER). This signal is a result of the receiver operation obtained by combining the received signal and the interference signal, and can more accurately represent the reception quality than the conventional determination by observing the received intensity using only RSSI. Needless to say. In addition, variations in determination due to variations in RSSI values can be reduced.

  More specifically, when the quality of the demodulated signal is lower than the first reference quality level represented by the reference signal and the reception intensity level is higher than the first reference intensity level, the gain control unit 70 The gain of the amplification unit 20 is adjusted so that the gain of 20 becomes small. The gain control unit 70 increases the gain of the amplification unit 20 when the quality of the demodulated signal is lower than the second reference quality level represented by the reference signal and the reception intensity level is lower than the second reference intensity level. The gain of the amplification unit 20 is adjusted so that

  By doing so, it is possible to provide the receiving apparatus 10 that is not easily affected by the interference signal without lowering the receiving sensitivity.

  In addition, the configuration is not limited to the configuration illustrated in FIG. 1, and at least a part of the data processing circuit 50 may be built in the receiving device 10.

  FIG. 2 shows an operation explanatory diagram of the receiving apparatus 10 of FIG.

  In FIG. 2, the horizontal axis represents the gain of the amplification unit 20, the left vertical axis represents the reception sensitivity of the received signal, and the right vertical axis represents the influence of the interference signal. As shown in FIG. 2, the greater the gain, the higher the sensitivity of the received signal itself. However, in practice, not only the desired signal contained in the received signal is amplified, but also the interference signal is amplified. Therefore, as shown in FIG. 2, as the gain is increased, the influence of the interference signal is increased.

  Incidentally, as shown in FIG. 2, in the region P1 where the gain is large, the reception sensitivity is high, but the influence of the interference signal is also large. Here, when the determination result of the quality of the demodulated signal is negative, the cause may be that the reception intensity level is very low or the level of the interference signal is high. Therefore, in the latter case, if the gain of the amplifying unit 20 is reduced here, the absolute value of the reception sensitivity is lower than that in the high gain operation mode, but exceeds the absolute value of the reception sensitivity in the normal gain operation mode. Since the normal gain is selected so as to ensure the desired signal level and the desired signal level is ensured within a range where the reception quality can be ensured, reducing the gain of the amplifying unit 20 rather reduces the level of the interference signal. Can be lowered, and the effect can be reduced. Therefore, the reception quality of the demodulated signal can be improved. The quality determination result can be determined based on whether the quality of the demodulated signal is higher than the first reference quality level. The reception strength level can be determined based on the first reference strength level. In the former case, even in the high gain operation mode, the desired signal level is still too low, and it is in a state below the reception quality limit regardless of the strength of the interference signal.

  As shown in FIG. 2, in the region P2 where the gain is small, the influence of the interference signal is small, but the reception sensitivity is also low. Here, when the determination result of the quality of the demodulated signal is negative, the cause may be that the reception intensity level is low or the interference signal level is very high. Therefore, in the latter case, the influence of the disturbing signal is essentially small in the normal gain operation mode, but still the disturbing signal is excessive, and it is in a state below the reception quality limit regardless of the strength of the desired signal. In the former case, if the gain of the amplifying unit 20 is increased, the absolute value of the reception sensitivity is higher than that in the normal gain operation mode, so that the reception quality is improved in the environment of only the desired signal. This is established in the presence of an interference signal that does not significantly deteriorate the reception quality in the high sensitivity operation mode. Under such conditions, the quality of the demodulated signal can be improved. Therefore, the reception quality of the demodulated signal can be improved. This quality judgment result can be judged by whether the quality of the demodulated signal is higher than the second reference quality level. The reception strength level can be determined based on the second reference strength level.

  In summary, the region P1 has a high reception sensitivity but is vulnerable to interference. In the region P2, the reception sensitivity is normal but it is strong against interference. By appropriately switching between these two states, a receiver that has high reception sensitivity and resistance to interference can be configured. As a means for switching the state, when P1 to P2, the reception quality is deteriorated by the interference signal, and when P2 to P1, the reception quality is deteriorated by the desired signal.

  The first and second reference quality levels may be the same level. The first and second reference intensity levels may be the same level.

  As described above, by adjusting the gain of the amplifying unit 20 based on the quality of the demodulated signal and the reception intensity level, it is possible to suppress a decrease in reception sensitivity while suppressing an increase in the influence of the interference signal. Therefore, the desired signal can be extracted with high sensitivity, and the influence of the interference signal can be reduced.

2. Communication Controller Next, a detailed configuration example of a communication controller to which the receiving device in the present embodiment is applied will be described.

  FIG. 3 shows a configuration example of a communication apparatus including a communication controller to which the receiving apparatus in the present embodiment is applied. FIG. 3 illustrates a communication device including a communication controller that performs wireless communication in accordance with the Bluetooth (registered trademark) standard. However, the present invention is limited to one that performs wireless communication in accordance with the Bluetooth (registered trademark) standard. is not.

  The communication apparatus 100 includes an antenna 110, a band pass filter (BPF) 120, an impedance matching circuit 130, a communication controller 200, and a baseband engine 300. Note that the communication device 100 may have a configuration in which some of these are omitted.

  The communication device 100 transmits and receives a radio signal (a transmission signal and a reception signal) using a channel in a predetermined frequency band of 2.4 GHz band defined by Bluetooth (registered trademark). In the following, for example, a case where a 2.402 GHz radio signal is received from the communication partner via the antenna 110 is considered.

  A reception signal received by the antenna 110 is input to the BPF 120. The BPF 120 is a filter that passes a signal having a predetermined bandwidth having a center frequency of 2.400 GHz. Accordingly, the BPF 120 removes an interference signal having a non-passband frequency component.

  The impedance matching circuit 130 performs impedance matching so as to match the characteristic impedance in order to prevent signal reflection. The received signal including the desired signal that has passed through the BPF 120 is supplied to the communication controller 200 via the impedance matching circuit 130.

  The transmission signal is transmitted from the antenna 110 after the interference signal having the frequency component of the non-pass band is removed by the BPF 120 via the impedance matching circuit 130.

  Note that when the frequency of the radio signal is taken into consideration and the wavelength becomes long and it is difficult to integrate the antenna 110, it is desirable to provide the antenna 110 outside the communication controller 200 as shown in FIG. However, it is natural that the antenna 110 may be built in the communication controller 200.

  Similarly, when the area of the inductance element and the capacitor element constituting the BPF 120 is increased in order to sufficiently increase the attenuation amount of the non-pass band, the BPF 120 is provided outside the communication controller 200 as shown in FIG. It is desirable. However, it is natural that the BPF 120 may be built in the communication controller 200.

  Further, when it is necessary to adjust impedance matching with an external inductance element and capacitor element, it is desirable to provide an impedance matching circuit 130 outside the communication controller 200 as shown in FIG. However, as a matter of course, the impedance matching circuit 130 may be built in the communication controller 200.

  The communication controller 200 has the function of the receiving apparatus 10 in the present embodiment shown in FIG. 1 and includes a power amplifier (hereinafter abbreviated as PA) 202 for amplifying a transmission signal corresponding to transmission data. For this reason, the communication controller 200 includes a changeover switch RF_SW. Therefore, at the time of reception, the changeover switch RF_SW supplies the received signal to a low noise amplifier (hereinafter referred to as LNA) 210, and at the time of transmission, the changeover switch RF_SW impedance-matches the transmission signal amplified by the PA202. Supply to circuit 130.

  FIG. 4 shows a block diagram of a configuration example of the LNA 210 of FIG.

  The LNA 210 includes a small signal amplification circuit 212, a selection amplification circuit 214, and an output buffer circuit 219. The small signal amplification circuit 212 is a block having the largest gain among the LNAs 210 although the gain is adjusted based on the gain control signal. The selective amplification circuit 214 includes a BPF 216 and an amplifier 218, and the amplifier 218 amplifies only a signal having a frequency component of a predetermined bandwidth that passes through the BPF 216. Operate. The output buffer circuit 219 amplifies the signal amplified by the amplifier 218.

  FIG. 5 shows a block diagram of a configuration example of the small signal amplifier circuit 212 of FIG.

  The small signal amplifier circuit 212 includes a changeover switch SW, a high gain amplifier (first amplifier) PA1, and a normal gain amplifier (second amplifier) PA2. The high gain amplifier PA1 amplifies the input signal with a first gain. The normal gain amplifier PA2 amplifies the input signal with a second gain lower than the first gain.

  The changeover switch SW supplies the input signal of the small signal amplifier circuit 212 to the high gain amplifier PA1 or the normal gain amplifier PA2 based on the gain control signal. When the changeover switch SW supplies the input signal of the small signal amplifier circuit 212 to the high gain amplifier PA1 by the gain control signal, the operation of the normal gain amplifier PA2 is stopped and the operating current of the normal gain amplifier PA2 is stopped or limited. Is desirable. When the changeover switch SW supplies the input signal of the small signal amplifier circuit 212 to the normal gain amplifier PA2 by the gain control signal, the operation of the high gain amplifier PA1 is stopped and the operating current of the high gain amplifier PA1 is stopped or limited. Is desirable.

  The LNA 210 shown in FIGS. 4 and 5 realizes the function of the amplification unit 20 shown in FIG. Here, the operation mode of the communication controller (receiver) that amplifies the received signal by the high gain amplifier PA1 (first amplifier) is the high gain operation mode (first mode), and the received signal is the normal gain amplifier PA2 (second amplifier). The operation mode of the communication controller (receiver) that is amplified by the amplifier) is the normal gain operation mode (second mode). In this case, the gain of the LNA 210 is adjusted by switching from one of the high gain operation mode and the normal gain operation mode (first and second modes) to the other mode. .

Returning to FIG. 3, the description will be continued. The received signal amplified by the LNA 210 is supplied to a mixer 220. The mixer 220 receives the local oscillation signal L ₀ having a frequency of 2.400 GHz from the frequency divider 222, and converts the frequency of the received signal from the LNA 210 to the vicinity of the intermediate frequency. The BPF 224 passes the reception signal converted to the vicinity of the intermediate frequency by the mixer 220.

  FIG. 6 shows the relationship between the frequency of the received signal and the frequency of the local oscillation signal.

In the vicinity of the center frequency 2.402GHz of the received signal _{S 0,} there is a reception signal S1. Also in the vicinity of the center frequency 2.400GHz of the local oscillation signal _{L o,} interference signal S2 is present. The difference between the center frequency of the received signal _{S 0,} the center frequency of the local oscillation signal _{L o} is 2MHz.

  FIG. 7 is an operation explanatory diagram of the mixer 220.

By multiplying by the mixer 220 is amplified received signal S1 and the local oscillation signal L ₀ in LNA210 6, components of the sum and difference of the frequencies of the two signals is output. As a result, the frequency of the received signal S1 is converted around 2 MHz, which is the difference in frequency, and the frequency of the interference signal S2 is converted around DC. Here, when the level of S2 ′ is very large, S1 ′ is suppressed by S2 ′, the amplitude component of S1 ′ is limited to the dynamic range of the mixer 220, and the information of S1 ′ starts to be lost. The reception quality deteriorates due to this omission. On the other hand, the BPF 224 in FIG. 3 passes only S1 ′ out of the output signal of the mixer 220 as a passband having a predetermined bandwidth whose center frequency is 2 MHz. Although S2 ′ is subjected to a furnace wave, since S1 ′ has already received information loss, the final reception quality deteriorates.

  The received signal that has passed through the BPF 224 is amplified by the limiter amplifier 226 and the amplitude is limited to a given level. The signal amplified by the limiter amplifier 226 is also supplied to the A / D converter 228, and the A / D converter 228 outputs RSSI.

  FIG. 8 shows a configuration example of the limiter amplifier 226 and the A / D converter 228 in FIG.

  In FIG. 8, four stages of amplifiers having the same gain are connected in series, but the number of stages is not limited to this. The output of each amplifier is input to each A / D converter and converted into a digital value corresponding to the amplitude of the output of each amplifier.

  Limiter amplifier 226 outputs an amplified output signal until the amplitude of the input signal is limited at a given level in order to remove residual AM components. In order to keep the output signal, which is the output of the amplifier at the final stage of the limiter amplifier 226, in a state where the amplitude is always limited, the amplifier is applied so that the limiter is applied even when the input of the limiter amplifier 226 is very small (reception sensitivity point). Determine the gain of each stage. When the input is higher than this level, the final stage amplifier output is naturally limited by the limiter, and the limiter is applied one after another according to the input level in each preceding stage.

  The digital values converted by each A / D converter are added by an adder ADD. The addition result of the adder ADD is RSSI. That is, the RSSI can indicate a digital value proportional to the electric field strength or power of the received signal including the desired signal and the interference signal by setting the sum of the digital values corresponding to the amplitude of each amplifier.

  In place of the A / D converter 228, a rectifier circuit that can be realized by a diode or a CMOS (Complementary Metal Oxide Semiconductor) transistor circuit is provided, and envelope detection of the output of each stage of the limiter amplifier 226 is performed. A method may be used in which a certain detected current is analog-added by an adder ADD and then converted into a digital value by a single A / D converter (not shown).

  It goes without saying that several methods described in the literature can be used as the above-described method for obtaining the RSSI.

  The limiter amplifier 226, the A / D converter 228, and the adder ADD illustrated in FIG. 8 implement the function of the reception intensity detection unit 30 illustrated in FIG.

  In FIG. 3, the FM detection circuit 230 detects a change in the frequency of the output of the limiter amplifier 226, extracts a desired signal from the received signal, and outputs it as a demodulated signal. Since the configuration and operation of the FM detection circuit 230 are known, detailed description thereof is omitted.

  The demodulated signal generated by the FM detection circuit 230 is received data binarized by the data slicer 234 after high-frequency component noise is removed by a low pass filter (hereinafter referred to as LPF) 232. Is generated. This received data is supplied to the baseband engine 300 as a demodulated signal. Here, the FM detection circuit 230 implements the function of the demodulator 40 of FIG.

  Note that the RSSI generated by the A / D converter 228 and the adder ADD shown in FIG. 8 is supplied to the baseband engine 300 by the control circuit 240. The control circuit 240 controls each part of the communication controller 200.

  In the Bluetooth (registered trademark) standard, communication is performed using a frequency hopping (FH) system. Therefore, wireless communication is performed at a frequency specified by the baseband engine 300 according to a given hopping pattern. For example, the control circuit 240 includes a frequency setting register 242, and the frequency is set by the baseband engine 300 in the frequency setting register 242.

  A PLL (Phased Locked Loop) circuit 244 converges to a target frequency according to the characteristics of the PLL loop filter based on the set value of the frequency setting register 242. When the frequency matches the set value after convergence, the clock CLK, which is the oscillation output of the crystal oscillator OSC, is multiplied by a corresponding multiplication factor, and the multiplied clock is supplied to a voltage controlled oscillator (VCO) 246. To do. The clock CLK is supplied as a reference clock for the baseband engine 300.

The output of the VCO 246 is demultiplexed by the demultiplexer 245, and the output is used as a local oscillation signal output at the time of reception or a transmission signal output at the time of transmission, and further used for frequency division of the PLL loop. For frequency division of the PLL loop, it is output to the frequency divider 222, frequency-divided by the frequency divider 222 to substantially the same frequency as the crystal oscillator OSC, and further frequency and phase-compared by a comparator (not shown). A voltage is finally generated according to the comparison result to control the frequency of the VCO. The details of the operation of the PLL are the same as those in a general example, and thus description thereof is omitted. The output of the duplexer 245 is output as a local oscillation signal L ₀ of 2.400 GHz, for example, at the time of reception. At the time of transmission, the transmission data from the baseband engine 300 is subjected to FM modulation in the VCO 246 after the high frequency component is removed by the LPF 248, and output as a transmission signal via the duplexer 245. This transmission signal is amplified by the PA 202 and supplied to the changeover switch RF_SW. The changeover switch RF_SW performs a changeover operation in accordance with a control signal from the control circuit 240. Note that the transmission signal output from the demultiplexer 245 can reduce out-of-band radiation by the BPF 120, but it is also possible to incorporate a BPF if necessary, and out of a predetermined frequency band via a BPF (not shown). May then be amplified by PA202.

  Communication controller 200 includes a bias generation circuit 250. The bias generation circuit 250 generates a constant current or a constant voltage and supplies the constant current or a constant voltage to each unit constituting the communication controller 200. The configuration of the communication controller 200 is not limited to that shown in FIG. 3, and may be a configuration in which some of the blocks shown in FIG. 3 are omitted.

  FIG. 9 shows a block diagram of a configuration example of the baseband engine 300 of FIG.

  The baseband engine 300 implements the function of the data processing circuit 50 in FIG. Therefore, the baseband engine 300 includes a received data quality determination unit 310, an RSSI determination unit 320, a gain control unit 330, and a data processing unit 340. The data processing unit 340 includes a reception data processing unit 342 and a transmission data generation unit 344.

  The reception data quality determination unit 310 realizes the function of the reception quality determination unit 60 of FIG. More specifically, the reception data quality determination unit 310 determines the quality of the reception data from the communication controller 200 by comparing the reception data with reference data. The determination result is notified to the gain control unit 330.

  The RSSI determination unit 320 determines the RSSI from the communication controller 200 by comparing it with a given reference level. The determination result is notified to the gain control unit 330.

  The gain control unit 330 realizes the function of the gain control unit 70 of FIG. More specifically, the gain control unit 330 controls the communication controller 200 to adjust the gain of the LNA 210 based on the determination result of the received data quality determination unit 310 and the determination result of the RSSI determination unit 320 ( Gain control signal). This signal is a digital binary signal, a multi-value signal, or a digital value with a change in pulse duty, such as PWM (Pulse Width Modulation) format, and is smoothed by a filter to extract an arbitrary voltage. You may do it.

  The reception data processing unit 342 performs processing for analyzing and processing the reception data from the communication controller 200. The transmission data generation unit 344 performs processing for generating transmission data.

  FIG. 10 shows a block diagram of a configuration example of the reception data quality determination unit 310 of FIG.

  Received data quality determination unit 310 includes an access code detection unit 312, an access code setting register 314, and a comparator 316. The access code detection unit 312 analyzes the packet structure of the received data and detects an access code included in the packet.

  FIG. 11 shows an example of a packet structure of received data in the present embodiment.

  The received data includes packet data having a structure shown in FIG. This packet data includes a preamble code, an access code (identification code in a broad sense) unique to the communication apparatus 100, a header, and a payload. The preamble code is a code for achieving bit synchronization. The access code is a unique code assigned to the communication device 100. The header includes an address in a piconet to which a plurality of communication devices called slaves are simultaneously connected to one communication device called a master, a packet type, a checksum for error correction, and the like. The payload is data to be communicated (for example, a signal obtained by digitizing an audio signal).

  The access code detector 312 analyzes the structure of the packet data shown in FIG. 11 and extracts the access code from the received data. In the access code setting register 314, a reference access code (first or second reference quality level) (reference signal in a broad sense) as a reference code is set in advance. The comparator 316 compares the access code detected by the access code detection unit 312 with the reference access code set in the access code setting register 314, and outputs the comparison result as a determination result signal.

  The reception data quality determination unit 310 may determine the quality of the reception data based on the determination result signal, or the ratio of the number of times matched by the determination result signal within a predetermined number of determinations. The quality of the received data may be determined based on the quality.

  FIG. 12 shows a block diagram of a configuration example of the RSSI determination unit 320 of FIG.

  The RSSI determination unit 320 includes a reference level setting register 322 and a comparator 324. The reference level setting register 322 is set with a reference level (first or second reference intensity level) in a broad sense. The comparator 324 compares the reference level set in the reference level setting register 322 with the RSSI from the communication controller 200, and outputs the comparison result as a determination result signal.

  The RSSI determination unit 320 may determine whether or not the RSSI is large based on the determination result signal, and within a predetermined number of determinations, the RSSI determination unit 320 may indicate that the RSSI is large (or small) by the determination result signal. It may be determined whether the RSSI is large based on the ratio of the indicated number of times.

  The function of each part of the baseband engine 300 as described above is a central processing unit (hereinafter referred to as a CPU) that reads a program (software or firmware) stored in a memory and executes a function corresponding to the program. Abbreviation) or hardware such as a logic circuit.

  FIG. 13 shows a flowchart of a processing example of the baseband engine 300 of FIG.

  For example, a program that designates the following processing is stored in the memory, and the CPU can read the program from the memory so that the following processing can be executed.

  First, the gain controller 330 of the baseband engine 300 supplies a gain control signal to the communication controller 200 so as to operate in the high gain operation mode (step S400). As a result, the LNA 210 amplifies the received signal with the high gain amplifier PA1.

  Next, gain control section 330 detects whether or not the quality of the received data is determined to be good based on the determination result of received data quality determination section 310 (step S401). In step S401, when it is detected that the quality of the received data is determined to be negative (step S401: N), the gain control unit 330 determines that the RSSI is lower than a given reference level based on the determination result of the RSSI determination unit 320. Whether it is larger is detected (step S402).

  When it is detected in step S401 that the quality of the received data is determined to be good (step S401: Y), the process returns to step S400.

  In step S402, when it is detected that the RSSI is greater than a given reference level (step S402: Y), the gain control unit 330 sends a gain control signal to the communication controller 200 so as to operate in the normal gain operation mode. Supply (step S403). Thereby, the LNA 210 amplifies the received signal by the normal gain amplifier PA2. This step indicates that the desired signal is large but the quality is poor because it is disturbed.

  In step S402, when it is detected that the RSSI is not larger than the given reference level (step S402: N), it is detected whether or not communication is possible (step S404). When the baseband engine 300 determines that communication is not possible due to error correction or the like because the RSSI is small and the received data quality is not good (step S404: N), the series of processing ends (end).

  On the other hand, when the baseband engine 300 determines in step S404 that communication can be continued (step S404: Y), the process returns to step S400.

  After the normal gain operation mode is set in step S403, gain control section 330 detects whether or not the quality of received data is determined to be good based on the determination result of received data quality determination section 310 (step S405). In step S405, when it is detected that the quality of the received data is determined to be negative (step S405: N), the gain control unit 330 determines that the RSSI is less than a given reference level based on the determination result of the RSSI determination unit 320. Whether it is larger is detected (step S406).

  When it is detected in step S405 that the quality of the received data is determined to be good (step S405: Y), the process returns to step S403.

  When it is detected in step S406 that the RSSI is not greater than the given reference level (step S406: N), the gain control unit 330 causes the communication controller 200 to operate in the high gain operation mode. Is supplied (step S400). As a result, the LNA 210 amplifies the received signal with the high gain amplifier PA1. This step indicates that the high gain operation mode is selected because the reception quality cannot be maintained in the normal gain operation mode.

  In step S406, when it is detected that the RSSI is larger than a given reference level (step S406: Y), it is detected whether or not communication is possible (step S407). When the baseband engine 300 determines that the received data quality is not good even though the RSSI is large, the influence of the interference signal is very large and, for example, communication cannot be performed by error correction or the like (step S407: N). End the processing of (end).

  On the other hand, when the baseband engine 300 determines in step S407 that communication can be continued (step S407: Y), the process returns to step S403.

  That is, when the quality of the received data as a demodulated signal is determined based on the first reference quality level, the quality is lower than the first reference quality level, and the RSSI as the reception intensity level is the first reference level. When it is larger than the intensity level, the high gain operation mode (first mode) is switched to the normal gain operation mode (second mode) (steps S401, S402, and S403).

  Further, when the quality of the received data as the demodulated signal is determined based on the second reference quality level, the quality is lower than the second reference quality level, and the RSSI as the received intensity level is the second reference level. When it is smaller than the intensity level, the normal gain operation mode (second mode) is switched to the high gain operation mode (first mode) (steps S405, S406, S400).

  FIG. 14 is an explanatory diagram of operation modes in the present embodiment.

  The gain control unit 330 illustrated in FIG. 9 performs a high gain operation mode (first mode) or a normal gain for the communication controller 200 based on the determination result of the reception data quality determination unit 310 and the determination result of the RSSI determination unit 320. Control to set the operation mode (second mode) is performed.

  In the high gain operation mode, the reception sensitivity is increased, but the influence of an interference wave (interference signal) is increased. In the normal gain operation mode, the reception sensitivity is at a normal level, but the influence of an interference wave (interference signal) can be reduced. As a result, the anti-jamming characteristics can be improved as the communication controller 200 by switching to the normal gain operation mode.

  Here, when the reception data quality determination unit 310 determines that the quality of the reception data is not good, in the high gain operation mode, the cause is that the level of the desired wave is very small or the level of the interference wave Is larger than the desired wave. Accordingly, when the RSSI is larger than a given level, the level of the interference wave can be lowered by lowering the gain of the LNA 210, and as a result, the quality of the received data can be improved. Therefore, the high gain operation mode is switched to the normal gain operation mode.

  On the other hand, when it is determined that the quality of the received data is not good according to the determination result of the received data quality determination unit 310, the cause is that the level of the desired wave is low or the interference wave is very large in the normal gain operation mode. Can be considered. Therefore, when the RSSI level is smaller than a given level, the quality of the received data can be improved by increasing the gain of the LNA 210. Therefore, the normal gain operation mode is switched to the high gain operation mode.

  FIG. 15 shows an explanatory diagram when switching from the high gain operation mode to the normal gain operation mode in the present embodiment.

  In FIG. 15, the horizontal axis indicates the strength of the interference wave (interference signal), and the vertical axis indicates the communication quality (reception data quality). The received data quality limit corresponds to the reference quality level. Further, when the communication quality falls below the communicable quality limit, it indicates that communication is impossible.

  As shown in FIG. 13, the initial state of the communication controller 200 starts from the high gain operation mode. From this time, the reception quality is constantly observed. Here, consider a case where reception quality has changed and deteriorated. In the present embodiment, when the communication quality falls below the received data quality limit, it is determined whether the RSSI is greater than the reference level.

  In a state where the communication quality is below the received data quality limit, if the RSSI is smaller than the reference level, the communication controller 200 operates in the high gain operation mode. However, in a state where the communication quality is below the received data quality limit, when the RSSI becomes greater than the reference level, the communication controller 200 operates by switching to the normal gain operation mode. Therefore, communication quality is improved. If the interference wave is stronger, the reception quality is deteriorated. As a result, in the normal gain operation mode, the communication quality becomes impossible when the communication quality falls below the communicable quality limit.

  That is, in FIG. 15, according to the level of the interference wave, switching from the high gain operation mode to the normal gain operation mode, the interference wave strength that falls into the communication impossible state is the interference wave strength shown in FIG. The amount of change E1 can be moved, and the influence of the disturbing wave can be made less susceptible to ensuring the communication quality.

  FIG. 16 shows an explanatory diagram when switching from the normal gain operation mode to the high gain operation mode in the present embodiment.

  In FIG. 16, the horizontal axis indicates the strength of the desired wave (desired signal), and the vertical axis indicates the communication quality (received data quality). The received data quality limit corresponds to the reference quality level. Further, when the communication quality falls below the communicable quality limit, it indicates that communication is impossible.

  Here, consider a case where reception quality has changed and deteriorated. In the present embodiment, when the communication quality falls below the received data quality limit, it is determined whether the RSSI is greater than the reference level.

  In a state where the communication quality is below the received data quality limit, if the RSSI is greater than the reference level, the communication controller 200 operates in the normal gain operation mode. However, in a state where the communication quality is below the received data quality limit, when the RSSI becomes smaller than the reference level, the communication controller 200 operates by switching to the high gain operation mode. Therefore, communication quality is improved. If the desired signal is further weak, the reception quality is deteriorated. As a result, in the high gain operation mode, communication becomes impossible when the communication quality falls below the communicable quality limit.

  That is, in FIG. 16, the strength of the desired wave that falls into the communication impossible state by switching from the normal gain operation mode to the high gain operation mode according to the level of the desired wave is the strength of the desired wave shown in FIG. It is possible to communicate even with a weaker desired wave without lowering the communication quality by moving by the change amount E2.

  Note that the reception data quality determination unit 310 in the present embodiment is not limited to that shown in FIG.

  FIG. 17 is a block diagram showing another configuration example of the reception data quality determination unit 310 shown in FIG.

  Reception data quality determination unit 310 includes a bit error rate detection unit 500, a reference bit error rate setting register 510, and a comparator 520. Bit error rate detection section 500 detects the bit error rate of received data. In the reference bit error rate setting register 510, a reference bit error rate (first or second reference quality level) (reference signal in a broad sense) as reference data is set. The comparator 520 compares the bit error rate detected by the bit error rate detection unit 500 with the reference bit error rate set in the reference bit error rate setting register 510, and outputs the comparison result as a determination result signal. .

  The reception data quality determination unit 310 may determine the quality of the reception data based on the determination result signal, or is smaller than the reference bit error rate by the determination result signal within a predetermined number of determinations ( Alternatively, the quality of the received data may be determined based on a ratio of the number of times indicating that the received data is high.

  FIG. 18 is a block diagram showing still another configuration example of the reception data quality determination unit 310 of FIG.

  Reception data quality determination unit 310 includes a packet error rate detection unit 600, a reference packet error rate setting register 610, and a comparator 620. The packet error rate detection unit 600 detects a bit error in units of packets obtained by analyzing received data having the packet structure shown in FIG. 11 as a packet error rate. In the reference packet error rate setting register 610, a reference packet error rate (first or second reference quality level) (reference signal in a broad sense) as reference data is set. Comparator 620 compares the packet error rate detected by packet error rate detection unit 600 with the reference packet error rate set in reference packet error rate setting register 610, and outputs the comparison result as a determination result signal. . As a method for detecting a packet error, a CRC code error detection function can be used.

  The reception data quality determination unit 310 may determine the quality of the reception data based on the determination result signal, or is smaller than the reference packet error rate by the determination result signal within a predetermined number of determinations ( Alternatively, the quality of the received data may be determined based on a ratio of the number of times indicating that the received data is high.

3. Electronic Device FIG. 19 is a block diagram showing a configuration example of an electronic device according to this embodiment.

  FIG. 19 shows a block diagram of a configuration example of a hands-free system as an example of an electronic device. 19, the same parts as those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  In the hands-free system 800, for example, a driver of a car can listen to sound from a speaker or input sound to a microphone while holding a hand on a steering wheel. The hands-free system 800 can wirelessly communicate audio data with, for example, a mobile phone. By doing so, it becomes possible to make and receive calls via the mobile phone without the driver operating the mobile phone while driving the automobile. In this case, wireless communication conforming to the Bluetooth (registered trademark) standard is performed with the mobile phone via the communication controller 200 and an antenna (not shown). For example, the communication controller 200 that has received an instruction from the host processor 810 (baseband engine 300) transmits a command for instructing outgoing calls to the mobile phone and a command for responding to incoming calls.

  The hands-free system 800 includes a host processor (application processor) 810 that controls each part of the hands-free system 800 in addition to the communication controller 200 and the baseband engine 300 shown in FIG.

  The host processor 810 controls each part of the hands-free system 800 based on a program and setting data stored in a read only memory (ROM) 820 and a random access memory (RAM) 830. The host processor 810 can use at least a part of the storage area of the RAM 830 as a work area.

  A USB (Universal Serial Bus) interface (InterFace: I / F) 840 and a UART (Universal Asynchronous Receiver Transmitter) I / F 850 are connected to the host processor 810, and audio is transmitted via the USB I / F 840 or UART I / F 850. Sends and receives data (data in a broad sense).

  An audio codec 860 is connected to the host processor 810. The audio codec 860 decodes audio data received via the USB I / F 840, the UART I / F 850 or the communication controller 200 and the antenna 110, converts the audio data into an analog signal by the D / A converter 870, and then the speaker 880 (in a broad sense). Voice output can be performed by the output unit. Alternatively, the audio codec 860 converts an audio signal input via the microphone 890 (in a broad sense, an input unit) into a digital signal by the A / D converter 900, encodes the audio signal, and performs USB I / F 840, UARTI / It can be transmitted to the communication partner via F850 or the communication controller 200.

  The clock generated by the clock generation circuit 910 is supplied to each part of such a hands-free system 800.

  The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the gist of the present invention.

  In the invention according to the dependent claims of the present invention, a part of the constituent features of the dependent claims can be omitted. Moreover, the principal part of the invention according to one independent claim of the present invention can be made dependent on another independent claim.

The block diagram of the outline | summary of a structure of the receiver in this embodiment. Operation | movement explanatory drawing of the receiver of FIG. The figure which shows the structural example of the communication apparatus containing the communication controller to which the receiver in this embodiment was applied. FIG. 4 is a block diagram of a configuration example of the LNA in FIG. 3. FIG. 5 is a block diagram of a configuration example of a small signal amplifier circuit in FIG. 4. The figure which shows the relationship between the frequency of a received signal, and the frequency of a local oscillation signal. Operation | movement explanatory drawing of the mixer of FIG. The figure which shows the structural example of the limiter amplifier and A / D converter of FIG. The block diagram of the structural example of the baseband engine of FIG. FIG. 10 is a block diagram of a configuration example of a reception data quality determination unit in FIG. 9. The figure which shows an example of the packet structure of the reception data in this embodiment. The block diagram of the structural example of the RSSI determination part of FIG. FIG. 10 is a flowchart of a processing example of the baseband engine of FIG. 9. Explanatory drawing of the operation mode in this embodiment. Explanatory drawing in the case of switching from high gain operation mode to normal gain operation mode in this embodiment. Explanatory drawing in the case of switching from normal gain operation mode to high gain operation mode in this embodiment. FIG. 10 is a block diagram of another configuration example of the received data quality determination unit in FIG. 9. FIG. 10 is a block diagram of still another configuration example of the reception data quality determination unit in FIG. 9. 1 is a block diagram of a configuration example of an electronic device according to an embodiment.

Explanation of symbols

10 receiving device, 20 amplifying unit, 30 received intensity detecting unit, 40 demodulating unit,
50 data processing circuit, 60 reception quality judgment unit, 70 gain control unit,
100 communication device, 110 antenna, 120, 216, 224 BPF,
130 impedance matching circuit, 200 communication controller, 202 PA,
210 LNA, 212 small signal amplifier circuit, 214 selective amplifier circuit,
218 amplifier, 219 output buffer circuit, 220 mixer, 222 frequency divider,
226 limiter amplifier, 228 A / D converter, 230 FM detection circuit,
232, 248 LPF, 234 data slicer, 240 control circuit,
242 Frequency setting register, 244 PLL circuit, 245 demultiplexer,
246 VCO, 250 bias generation circuit, 300 baseband engine,
310 received data quality determination unit, 320 RSSI determination unit, 330 gain control unit,
340 data processing unit, 342 reception data processing unit, 344 transmission data generation unit,
ADD adder, OSC crystal oscillator, PA1 high gain amplifier,
PA2 Normal gain amplifier, RF_SW, SW selector switch

Claims (16)

A receiving device for receiving a received signal including a desired signal and an interference signal,
An amplifying unit for amplifying the received signal;
A reception intensity detection unit for detecting a reception intensity level of the reception signal amplified by the amplification unit;
A demodulation unit that generates a demodulated signal obtained by demodulating the reception signal amplified by the amplification unit,
A receiving apparatus, wherein the gain of the amplifying unit is adjusted based on the reception intensity level and a determination result obtained by determining whether the quality of the demodulated signal is good or not based on a reference signal. In claim 1,
A receiving apparatus comprising: adjusting a gain of the amplifying unit to be small when a quality of the demodulated signal is lower than a first reference quality level and the reception intensity level is higher than a first reference intensity level. . In claim 1 or 2,
A receiving apparatus, wherein the gain of the amplifying unit is adjusted to be large when the quality of the demodulated signal is lower than a second reference quality level and the received intensity level is lower than the second reference intensity level. . In claim 1,
The amplification unit is
A first amplifier that amplifies the input signal with a first gain;
A second amplifier for amplifying the input signal with a second gain lower than the first gain;
When the operation mode of the reception device that amplifies the reception signal by the first amplifier is the first mode, and the operation mode of the reception device that amplifies the reception signal by the second amplifier is the second mode In addition,
A reception characterized in that the gain of the amplification unit is adjusted by switching from one of the first and second modes to the other mode based on the reception strength level and the determination result. apparatus. In claim 4,
In the first mode, when the quality of the demodulated signal is lower than the first reference quality level and the reception strength level is higher than the first reference strength level, the first mode is changed to the second mode. A receiving device characterized by switching. In claim 4 or 5,
In the second mode, when the quality of the demodulated signal is lower than the second reference quality level and the reception strength level is lower than the second reference strength level, the second mode is changed to the first mode. A receiving device characterized by switching. In any one of Claims 1 thru | or 6.
The determination result is
A receiving apparatus, wherein the quality of the demodulated signal is determined by comparing the identification code or access code included in the demodulated signal with a given reference code. In any one of Claims 1 thru | or 6.
The determination result is
A receiving apparatus, wherein the quality of the demodulated signal is judged to be good or bad by comparing a bit error rate of the demodulated signal with a given reference bit error rate. In any one of Claims 1 thru | or 6.
The determination result is
A receiving apparatus characterized in that the quality of the demodulated signal is judged by comparing the packet error rate obtained as a result of analyzing the demodulated signal with a given reference packet error rate. In any one of Claims 1 thru | or 9,
The reception intensity detection unit
A limiter amplifier for amplifying the received signal and limiting the amplitude to a given level;
The demodulator
A receiving apparatus comprising an FM (Frequency Modulation) detection circuit for detecting a change in frequency of the demodulated signal. A first amplifier that amplifies the input signal with a first gain;
A second amplifier for amplifying the input signal with a second gain lower than the first gain;
A control method of a receiving apparatus that operates in a first mode in which a received signal including a desired signal and an interference signal is amplified by the first amplifier, or in a second mode in which the received signal is amplified by the second amplifier. There,
Amplifying the received signal with the first or second amplifier;
Detecting the received intensity level of the amplified received signal and demodulating the received signal;
Compare the demodulated signal obtained by demodulation and the reference signal to determine the quality of the demodulated signal,
A method for controlling a receiving apparatus, wherein the mode is switched from one of the first and second modes to the other mode based on a determination result of quality of the demodulated signal and the reception strength level. . In claim 11,
In the first mode, when the quality of the demodulated signal is lower than the first reference quality level and the reception strength level is higher than the first reference strength level, the first mode is changed to the second mode. A control method for a receiving apparatus, characterized by switching. In claim 11 or 12,
In the second mode, when the quality of the demodulated signal is lower than the second reference quality level and the reception strength level is lower than the second reference strength level, the second mode is changed to the first mode. A control method for a receiving apparatus, characterized by switching. A power amplifying unit for amplifying a transmission signal obtained by modulating transmission data;
A communication controller comprising: the receiving device according to claim 1. A communication controller according to claim 14;
A base for outputting a transmission data to the communication controller, including a quality determination unit that determines the quality of the demodulated signal by comparing reference data and received data corresponding to the demodulated signal from the communication controller An electronic device comprising a band engine. In claim 15,
An electronic apparatus comprising: an antenna for transmitting a transmission signal corresponding to the transmission data and receiving a reception signal corresponding to the reception data.

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