JPH0936816A - Radio communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the interference from an electronic range in the spread spectrum system radio communication, for the most part, in an ISM(Industrial Scientific And Medical) band. SOLUTION: When detecting an interference wave detection in a transmission, the interference wave from outside received by an antenna 1 is inputted in a band-pass filter 5 and an interference wave is extracted for a required band component. An AM detection is performed for the extracted interference wave in a detection part 6 and the wave is delivered to an interference wave detection part 7. The interference detection part 7 detects the level of the interference wave and the generating period from the detection signal. The detected level is compared with a preliminarily fixed reference level 9 in a comparison part 8. When the interference wave level is larger than the reference level 9, a transmission control part 10 controls a transmission part 4 to perform a transmission for the period when the interference wave does not exist, based on the same detected interference wave generation period. When the interference wave level 9 is smaller than the reference level, the transmission control part 10 controls the transmission part 4 to perform not an intermittent transmission but a continuous transmission.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication device, and more particularly to ISM (Industrial ScientficAnd Medica).
l) Mainly related to measures against interference in spread spectrum wireless communication in the band.

[0002]

2. Description of the Related Art The ISM band [2.4 to 2.5 (GH
z)] is currently a spread spectrum wireless communication [2.4.
84 ± 0.013 (GHz)]. This ISM
There is a microwave oven that emits an interfering wave in the band, which is an obstacle to spread spectrum communication. The frequency component of this interfering wave is distributed in the entire band, apart from its level. Conventionally, as a countermeasure against the interference by the microwave oven, a general method such as code error correction or waveform equalization has been used.

[0003]

However, the interference wave of the microwave oven is so strong that the above-mentioned measures alone may not be sufficient. On the other hand, it is known that the interference wave of this microwave oven has periodicity. FIG. 4 is an explanatory view of this periodic microwave interference wave. Interfering waves are emitted intermittently in synchronization with the power supply frequency of the microwave oven (50Hz or 60Hz). In FIG. 4, the cycle T1 matches the power cycle. T2 indicates the period of generation of the interfering wave, and T3 indicates the period of no generation of the interfering wave.
It should be noted that although the interference wave level is constant in the figure, this is a diagram for explanation and is not necessarily a constant level. Therefore, if the periodicity of the interfering wave is used and the transmission is performed during the period (T3) when the interfering wave is not radiated, the influence of the interfering wave can be avoided. The present invention has been made from this point of view, and an object of the present invention is to provide a wireless communication device that avoids the influence of a periodic interference wave such as an interference wave from a microwave oven.

[0004]

According to the present invention, one antenna is switched to a receiving section side or a transmitting section side to perform reception or transmission, and the antenna is switched to a transmitting side. At this time, a band pass filter for extracting a required band component of an external interference wave received by the same antenna and an interference wave from the band pass filter are
A detection unit for M detection, an interference wave detection unit for detecting the level and generation period of the interference wave from the detection signal from the detection unit,
A comparison unit that compares the interference wave level detected by the interference wave detection unit with a predetermined reference level, and controls the comparison unit, and when the interference wave level exceeds the reference level in the comparison of the comparison unit, the interference wave A wireless communication device comprising: a transmission control unit that controls the transmission unit so as to perform transmission during a period in which the interference wave does not exist, based on the generation period of the interference wave detected by the detection unit.

[0005]

[Action]

(1) When performing interference wave detection at the time of transmission The external interference wave received by the antenna is input to the bandpass filter, and the interference wave is extracted for the required band component. The detected interfering wave is subjected to AM detection by the detecting section and sent to the interfering wave detecting section. The interference wave detection unit detects the level of the interference wave and the generation period from the detection signal. The detected level is compared with a predetermined reference level in the comparison unit, and if the interfering wave level is higher than the reference level, transmission is performed during the period when no interfering wave exists based on the same detected interfering wave generation period. Then, the transmission control unit controls the transmission unit. On the other hand, when the interfering wave level is lower than the reference level, the transmission control unit controls the transmission unit so that continuous transmission is performed instead of the intermittent transmission as described above.

(2) When the interference wave is detected at the time of reception The purpose of the bandpass filter, the detection section and the interference wave detection section is the same as in the previous section. Data relating to the level of the interfering wave detected by the interfering wave detecting unit and the generation period is stored in the memory unit. The stored interference wave level is compared with the reference level in the comparison unit as in the previous section, and when the interference wave level is higher than the reference level, when the reception state is switched to the transmission state,
Similarly, based on the detected interference wave generation period, the transmission control unit controls the transmission unit so that transmission is performed during a period in which no interference wave exists. Further, as in the previous section, when the interfering wave level is lower than the reference level, the transmission control unit controls the transmission unit so as to perform continuous transmission instead of the intermittent transmission as described above.

(3) When Detecting Interfering Wave from Detecting Correlator Output Signal in Spread Spectrum Signal Reception The interfering wave extracting section extracts an interfering wave from the correlator output signal. The level of the extracted disturbing wave and the generation period are detected by the disturbing wave detector. Data relating to the level of the detected interfering wave and the generation period is stored in the memory unit. The stored interference wave level is compared with the reference level in the comparison unit as in the previous section.If the interference wave level is higher than the reference level, the same detected interference wave period when switching from the receiving state to the transmitting state Based on the above, the transmission control unit controls the transmission unit so that the transmission is performed during the period in which the interfering wave does not exist. Further, as in the previous section, when the interfering wave level is lower than the reference level, the transmission control unit controls the transmission unit so as to perform continuous transmission instead of the intermittent transmission as described above.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a radio communication device according to the present invention will be described with reference to the drawings. 1 is a block diagram of a main part of an embodiment of a wireless communication device according to the present invention, FIG. 2 is a block diagram of a main part of another embodiment, and FIG. 3 is a block diagram of a wireless communication device for spread spectrum communication. It is a principal part block diagram which shows the Example which did. In FIG. 1, 1 is an antenna that is used for both reception and transmission, 2 is a switching circuit that switches between reception and transmission, 3
Is a receiving unit, 4 is a transmitting unit, and 5 is a band-pass filter (hereinafter, referred to as “B”) that extracts a required band component from an external interference wave received by the antenna 1 while blocking a signal from the transmitting unit 4.
PF ”), 6 is AM due to the interfering wave from BPF 5.
A detecting section for detecting, 7 is an interfering wave detecting section for detecting the level of the interfering wave and the generation period from the detection signal by the detecting section 6, and 8 is a reference level for presetting the level of the interfering wave detected by the interfering wave detecting section 7. The comparing unit 10 for comparing with 9 controls the comparing unit 8 and, in comparison of the comparing unit 8, when the disturbing wave level exceeds the reference level, based on the generation period of the disturbing wave detected by the disturbing wave detecting unit 7, The transmission control unit controls the transmission unit 4 so that transmission is performed during a period in which the same interfering wave does not exist (intermittent transmission), and continuous transmission is performed when the interfering wave level is equal to or lower than the reference level.

In FIG. 2, those having the same functions as those in FIG. 1 are designated by the same reference numerals, and 21 is a memory section for storing data relating to the level of the interference wave detected by the interference wave detection section 7 and the generation period. , 22 control the memory unit 21 and the comparison unit 8, and
If the interfering wave level exceeds the reference level in the comparison by the comparing section 8, the interfering wave is detected based on the generation period of the interfering wave detected by the interfering wave detecting section 7 when the antenna 1 is switched from the receiving side to the transmitting side. The transmission control unit controls the transmission unit 4 so that transmission is performed during periods when there is no such signal (intermittent transmission), and continuous transmission is performed when the interference wave level is equal to or lower than the reference level.

Next, in FIG. 3, those having the same functions as those in FIG.
RF / IF unit for F conversion and amplification, 32 is RF / IF
A correlator that outputs a correlation signal that is the basis of demodulated data from the signal from the unit 31, 33 is an interference wave extraction unit that extracts an interference wave existing in the non-correlation period of the correlation output signal from the correlator 32, and 34 is an interference An interference wave detection unit that detects the level of the interference wave extracted by the wave extraction unit 33 and the generation period, 35 is a memory unit that stores data related to the level and the generation period of the interference wave detected by the interference wave detection unit 34, 36 is a comparison unit that compares the interference wave level stored in the memory unit 35 with a predetermined reference level 37, 38 controls the memory unit 35 and the comparison unit 36, and the interference wave level is compared in the comparison of the comparison unit 36. When exceeding the reference level, based on the generation period of the interfering wave detected by the interfering wave detection unit when switching the antenna from the receiving side to the transmitting side, transmission is performed during the period when the same interfering wave does not exist (intermittent transmission) , The disturbance level is below the reference level When it is below, a transmission control unit that controls the transmission unit 39 to continuously transmit, 40 is a correlation signal extraction unit that extracts a normal signal component existing in the correlation period of the correlation output signal from the correlator 32, and 41 is a correlation A clock generation unit that generates a clock signal based on the output signal.

Next, the operation of the present invention will be described with reference to the drawings. (1) Description of FIG. 1 FIG. 1 shows an embodiment in which an interference wave is detected during transmission. Therefore, when the switching circuit 2 is on the receiving side (a side), the operation is the same as the conventional operation. The switching circuit 2 is set to the transmitting side (b
Side), the antenna 1 is connected to the transmitter 4 and B
It is connected to PF5. The interference wave radiated from the microwave oven is received by the antenna 1 and input to the BPF 5.
The frequency component of the interference wave radiated from this microwave oven is
Aside from the level, as described above, the ISM band [2.
4 to 2.5 (GHz)]. Therefore,
Set this BPF5 to a band that does not overlap with the transmission frequency,
While interfering wave components within the band are taken out, mixing of the transmission signal (transmission unit 4) (backflow) is prevented.

The interfering wave extracted by the BPF 5 is detected by the detection unit 6
AM detection at. Based on this detection signal, the interference wave detection unit 7
The level of the interfering wave and the generation period are detected by. The purpose of level detection is to determine whether to perform intermittent transmission or continuous transmission described below, and the purpose of detecting the interfering wave generation period is to determine the transmission timing in the case of intermittent transmission. As described above (FIG. 4), the disturbance wave radiated from the microwave oven is not continuous, but has an intermittent characteristic synchronized with the power supply frequency (50 Hz or 60 Hz). Therefore, the influence of the interfering wave can be avoided by detecting the period (T3 in FIG. 4) in which the interfering wave does not exist and transmitting during the period. Therefore, the transmission control unit 10 causes the comparison unit 8 to compare the interference wave level with the reference level 9, and if the level of the interference wave exceeds the reference level in the comparison, based on the generation period of the similarly detected interference wave. The transmission unit 4 is controlled so that the transmission is performed during the period when the interference wave does not exist. That is, intermittent transmission is performed for each period when there is no interfering wave.

On the other hand, when the interfering wave level is lower than the reference level, the influence of the interfering wave is small, so that the transmission control unit
Reference numeral 10 controls the transmission unit 4 so as to perform continuous transmission as in the conventional case. As described above, since the BPF 5 is set to a band that does not overlap with the transmission frequency, the interference wave component included in the transmission band will not be detected, but the interference wave component also exists outside the transmission band. Therefore, it is considered that the function of the present invention is sufficiently achieved by detecting this.

(2) Description of FIG. 2 FIG. 2 shows an embodiment in which an interference wave is detected during reception. The basic functions of the BPF 5, the detection unit 6, the interfering wave detection unit 7, and the comparison unit 8 in the same figure are the same as those in FIG. In addition,
The BPF 5 has a band that does not overlap with the reception band of the reception unit 3. The invention finally consists in controlling the transmission. That is, the transmission is controlled when the switching circuit 2 is on the transmission side (b side). However, in the case of FIG. 2, since the interference wave detection is performed when the switching circuit 2 is on the receiving side (a), the same detection is not performed when the switching circuit 2 is switched to the transmitting side (b side). Therefore, the memory unit 11 is provided to store data relating to the level and position of the interference wave detected at the time of reception. The interference wave of the microwave oven is synchronized with the power supply as described above, and its level does not change greatly with time. Therefore, transmission control based on the stored data is possible. Therefore, when the switching circuit 2 is switched to the transmission side (b side), the transmission control unit 12 controls the transmission unit 4 based on the data stored in the memory unit 11 as in FIG.

(3) Description of FIG. 3 While FIGS. 1 and 2 are general embodiments in which the communication system is not specified, FIG. 3 is an embodiment based on the spread spectrum communication system. The frequency band used in this spread spectrum system is the ISM band. When the switching circuit 2 is on the side a, it is in the receiving state. RF / of the receiving system side
The IF unit 31, the correlator 32, the clock generation unit 41, and the like have the same functions as in the past. In the reception state, the signal (including the microwave interference wave) received by the attenuator 1 is amplified and frequency-converted (IF) by the RF / IF unit 31, and sent to the correlator 32.
A correlation signal is output from the correlator 32. In this correlation signal, the decorrelation period is essentially close to zero level. However, when the received signal contains the interference wave radiated from the microwave oven, it appears as a noise component in this decorrelation period. Therefore, the interference wave can be detected by extracting this noise component.

The disturbing wave extraction unit 33 is intended to extract the noise component in this non-correlation period. The clock signal required for this extraction operation is supplied from the clock generation unit 41. The clock generation unit 41 also generates a clock signal based on the correlation signal from the correlator 32. From the noise component extracted by the interference wave extraction unit 33, the interference wave detection unit 34 detects the level of the interference wave and the generation period. This detection is performed only when the switching circuit 2 is on the receiving side (a side), and is not detected when switching to the transmitting side (b side). Therefore,
As in the case of FIG. 2, a memory unit 35 is provided to store data relating to the level and position of the interference wave detected at the time of reception.
When the switching circuit 2 is switched to the transmission side (b side), the transmission control unit 38 uses the data stored in the memory unit 35 and the comparison unit 36 to compare the interfering wave level with the reference level 37. Two
The same control as is performed on the transmitting unit 39. The normal signal component is extracted from the output signal of the correlator 32 by the correlation signal extraction unit 40.

[0017]

As described above, according to the present invention, I
In spread spectrum wireless communication using the SM band, the level and generation period of an intermittently radiated interfering wave such as a microwave oven mixed in the band is detected, and this interfering wave level is the required level. If it is larger than the above, it is possible to select and transmit the period during which no interference wave is emitted. As a result, communication that avoids the influence of interfering waves becomes possible, and the transmission quality in wireless communication can be improved.

[Brief description of drawings]

FIG. 1 is a main block diagram showing an embodiment of a wireless communication apparatus according to the present invention.

FIG. 2 is a block diagram of main parts showing another embodiment of the wireless communication device according to the present invention.

FIG. 3 is a block diagram of essential parts showing an embodiment of a wireless communication device for spread spectrum communication according to the present invention.

FIG. 4 is an explanatory diagram of an interference wave generated by a microwave oven.

[Explanation of symbols]

 1 antenna 2 switching circuit 3 receiving unit 4 transmitting unit 5 band pass filter (BPF) 6 detecting unit 7 interfering wave detecting unit 8 comparing unit 10 transmitting control unit 21 memory unit 22 transmitting control unit 32 correlator 33 interfering wave extracting unit 34 interference Wave detection unit 35 Memory unit 36 Comparison unit 38 Transmission control unit 39 Transmission unit

Claims (4)

[Claims] 1. In a wireless communication apparatus configured to switch one antenna to a receiving section side or a transmitting section side to perform reception or transmission, when the antenna is switched to a transmitting side, the antenna is received by the same antenna. A bandpass filter for extracting a required band component of the external interference wave, a detection unit for AM detection of the interference wave from the bandpass filter, and a level of the interference wave and a generation period are detected from the detection signal from the detection unit. The disturbing wave detection unit, a comparing unit for comparing the disturbing wave level detected by the disturbing wave detecting unit with a predetermined reference level, and controlling the comparing unit, the disturbing wave level is a reference level in the comparison of the comparing unit. When exceeding, based on the generation period of the interference wave detected by the interference wave detection unit,
A radio communication device, comprising: a transmission control unit that controls the transmission unit so as to perform transmission during a period in which the interfering wave does not exist. 2. In a wireless communication device configured to switch one antenna to a receiving section side or a transmitting section side to perform reception or transmission, when the antenna is switched to a receiving side, the antenna is received by the same antenna. A bandpass filter for extracting a required band component of the external interference wave, a detection unit for AM detection of the interference wave from the bandpass filter, and a level of the interference wave and a generation period are detected from the detection signal from the detection unit. An interference wave detection unit, a memory unit that stores each of the data related to the level of the interference wave and the generation period, a comparison unit that compares the interference wave level stored in the memory unit with a predetermined reference level, Controls the memory section and the comparison section, and switches the antenna from the reception side to the transmission side when the interference level exceeds the reference level in the comparison of the comparison section. And a transmission control unit that controls the transmission unit so that the transmission is performed during a period in which the interference wave does not exist, based on the generation period of the interference wave detected by the interference wave detection unit when replaced. Wireless communication device. 3. A wireless communication apparatus configured to switch one antenna to a receiving section side or a transmitting section side to receive or transmit a signal by a spread spectrum system, when the antenna is switched to a receiving side. , An interfering wave extracting unit for extracting an interfering wave existing in a non-correlation period from a correlation output signal from a correlator provided on the receiving unit side, and a level and a generation period of the interfering wave extracted by the interfering wave extracting unit. An interfering wave detecting section for detecting, a memory section for storing each of the data relating to the level and the generation period of the interfering wave, and a comparing section for comparing the interfering wave level stored in the memory section with a predetermined reference level. Controlling the memory unit and the comparing unit, and switching the antenna from the receiving side to the transmitting side when the interfering wave level exceeds the reference level in the comparison of the comparing unit. At this time, based on the generation period of the interference wave detected by the interference wave detection unit, a transmission control unit for controlling the transmission unit so as to perform transmission during the period when the interference wave does not exist Wireless communication device. 4. The transmission control unit controls the transmission unit so as to continuously transmit when the interference wave level detected by the interference wave detection unit is below a required level. The wireless communication device according to claim 2 or 3.