JPH1117597A - Combination diversity reception system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combination diversity reception system by which deterioration in reception sensitivity caused on the occurrence of a fault of an antenna is minimized. SOLUTION: The system has antenna fault detection sections 7-1, 7-2 that detect an antenna fault and output the fault signals and a weight phase combination section 9 consisting of weight sections 9a-1, 9a-2 that apply weighting to signals based on a reception level of a reception signal from each antenna system, of a phase combination section 9c that puts together the weighted signals, and switch sections 9b-1, 9b-2 that block the weighted signal given to the phase combination section 9c based on a fault signal from the antenna fault detection section, and in the case that a fault is detected in the antenna, the weighted signals are stopped to be given to the phase combination section 9c the signals and deterioration in the reception sensitivity of the combination diversity is minimized by using only the reception signal of the system where no fault is in existence in the antennas 1-1, 1-2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combined diversity receiving system, and more particularly, to a combined diversity receiving system used in a radio apparatus for mobile communication.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing a conventional combined diversity receiving system. In the figure, signals of two systems received by two independent antennas 1-1 and 1-2 are respectively IF signals 4-1 and 4 which are intermediate frequency band signals by receiving units 2-1 and 2-2. Converted to -2. At the same time, the receiving units 2-1 and 2-2 output the received electric field detection signals 3-1 and 3-2 indicating the electric field strength of the received signal. Further, each of the IF signals 4-1 and 4-2 is supplied to a phase detector 5
-1, 5-2, and the result is output as phase information signals 6-1 and 6-2. The weighting / synthesizing unit 9 includes weighting units 9a-1 and 9a-2 and a phase synthesizing unit 9c. First, the weighting units 9a-1 and 9a-2 convert the phase information signals 6-1 and 6-2 into the reception electric field detection signal 3 respectively. −
Weighting is performed based on 1, 3-2. The weighted two-phase information signals are input to the phase synthesizer 9c and synthesized. The combined phase information is supplied to the demodulation unit 11 as a combined phase information signal 10. The demodulation unit 11 performs demodulation based on the combined phase information signal 10 and outputs demodulated data 12 as a result. That is, a method has been adopted in which the weighting when combining the two systems of received signals is determined by the reception level, and the two are combined according to the weight.
This technology is described in, for example, Japanese Patent Application Laid-Open No. 7-202775.

[0003]

In the conventional combined diversity receiving method, even when a failure occurs in an antenna and a received signal cannot be received from the antenna at all, the noise level of the receiver is detected and the failure is detected. There is a problem that the reception sensitivity is extremely deteriorated because the weighting synthesis is performed with the reception signal from the antenna system which is not performed.

[0004] The reason is that received signals of a system in which an antenna has failed are also subjected to weighting synthesis.

It is an object of the present invention to provide a combined diversity reception system capable of minimizing deterioration of reception characteristics when a failure occurs in an antenna of a device.

It is another object of the present invention to minimize the reduction of the service area of the base station and maintain the service quality even when a failure occurs in the antenna.

[0007]

According to a combined diversity receiving method of the present invention, in a combined diversity receiving method having a means for performing weighted combining, a detection result of a means for detecting an antenna abnormality is used for the means for performing weighted combining. It is characterized by.

That is, the combined diversity receiving method according to the present invention is a combined diversity receiving method that includes means for combining the phases of at least two reception signals having different phases weighted by the reception intensity from the antenna and the receiving means. It is characterized by having means for stopping the phase synthesis of the system using the detection result of the detecting means.

The means for suspending the phase synthesis of the system may include a switching means for disconnecting the input of the phase synthesis means for the phase information of the system by using the detection result of the means for detecting the antenna abnormality. There may be provided a multiplying means for invalidating the weighting of the reception signal of the system using the detection result of the means for detecting the antenna abnormality.

[0010] The combined diversity receiving system of the present invention comprises:
When an abnormality occurs in the antenna, the signal received from the antenna system is removed from the target of the weighting synthesis. More specifically, an antenna abnormality detection unit (7-1 and 7-2 in FIG. 1) for detecting abnormality of each antenna and a weighting unit (weighting a reception signal from each antenna system according to a reception level) 9a-1 and 9a-2 in FIG. 1 and a phase synthesizing unit (9c in FIG. 1) for synthesizing the weighted results;
When an abnormality occurs in the antenna, a switch unit (9b-) that prevents synthesis of a result weighted by the phase synthesis unit as an antenna abnormality detection signal (8-1, 8-2 in FIG. 1).
1, 9b-2).

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [1] Description of Configuration Next, a first embodiment of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1, a signal received from an antenna 1-1 is converted into an IF signal 4-1 by a receiving section 2-1 and a reception level is detected. And the result is output. IF signal 4-
1 is input to the phase detector 5-1 where the phase is detected, and the result is the phase information signal 6-1. An antenna abnormality detecting section 7-1 for detecting an abnormality of the antenna 1-1 is provided at an end of the antenna, and an antenna abnormality detection signal 8-1 for notifying the presence or absence of the abnormality is output. There is another similar receiving system including an antenna 1-2 and a receiving unit 2-2.
, An IF signal 4-2, a phase detector 5-2, a phase information signal 6-2, an antenna abnormality detector 7-2, and an antenna abnormality detection signal 8-2. The weighting / synthesizing unit 9 includes weighting units 9 a-1 and 9 a-2 and a switch unit 9.
b-1 and 9b-2, and a phase synthesizer 9c. The weighting section 9a-1 (9b-1) receives the received electric field detection signal 3-
1 (3-2), the phase information signal 6-1 (6-2) is weighted, and the antenna abnormality detection signal 8-1 (8-
The switch section 9b-1 (9b-
The signal is input to the phase synthesizer 9c via 2). The phase synthesizer 9c synthesizes the weighted phase information signals, and outputs the result to the demodulator 11 as a synthesized phase information signal 10. The demodulation unit 11 receives the synthesized phase information signal 10
Demodulation operation based on the demodulated data 1
2 is output.

In this configuration, there are two antenna systems. However, the number of antenna systems is not particularly limited to two, but may be three or more. [2] Description of Operation Next, the operation of FIG. 1 will be described with reference to the drawings.

Normally, the signals received from the antennas 1-1 and 1-2 are input to the receiving units 2-1 and 2-2, respectively, and the signals received by the receiving units 2-1 and 2-2 are IF signals. The signals are converted into signals 4-1 and 4-2, and the level of the signals is detected. The detected signal level is converted into a digital value from an analog voltage corresponding to the normal level, and then input to the weighting synthesis unit 9 as the received electric field detection signals 3-1 and 3-2. On the other hand, the IF signals 4-1 and 4-2 are subjected to, for example, delay detection by the phase detectors 5-1 and 5-2, and are output as phase information signals 6-1 and 6-2 indicating a state of a phase change. The operation of the weighting synthesis will be described with reference to FIG. 2 in addition to FIG. The weighting unit 9a-1 weights the phase information signal 6-1 of the signal received from the antenna system 1-1 according to the received electric field detection signal 3-1. In FIG. 2, it is assumed that the amount of change in the phase indicated by the phase information signal 6-1 is φ1, and the coefficient of weighting by the received electric field detection signal 3-1 is 3. The weighting section 9a-2 similarly weights the other system. In this system, it is assumed that the amount of change in the phase indicated by the phase information signal 6-2 is φ2, and the weighting coefficient by the received electric field detection signal 3-2 is 5. The signal after weighting is represented by the two vectors in FIG. The weighted signals are input to the switches 9b-1 and 9b-2, respectively. When the antenna is normal, the switch sections 9b-1 and 9b-2 are set to the ON state by the antenna abnormality detection signals 8-1 and 8-2.
As a result, the weighted phase information signal from each antenna is combined by the phase combining unit 9c. 2 in FIG.
Angle φ indicated by the vector obtained by combining the two vectors
Combined phase information signal 1 whose combination is output from phase combining section 9c
It becomes 0.

Next, a case where an abnormality occurs in the antenna will be described. Here, it is assumed that the antenna 1-2 is damaged. In this case, the receiver 2-2 performs level detection using the noise component of the receiver as a received signal. Therefore, the level of the noise is input to the weighting unit 9a-2 according to the received electric field detection signal 3-2. The phase information signal 6-2 also becomes phase information as a result of noise detection, is input to the weighting unit 9a-2, and is weighted by the received electric field detection signal 3-2.
The antenna abnormality detection unit 7-2 detects the abnormality of the antenna and notifies the switch unit 9b-2 that the antenna is abnormal by the antenna abnormality detection signal 8-2. The switch section 9b-2 receives this signal and switches the switch to the off state. As a result, the weighted phase information of the antenna system is not input to the phase synthesis unit 9c, and as a result, only the phase information of the other normal antenna system is transmitted to the demodulation unit 11 via the phase synthesis unit 9c. It is input and demodulated. [3] Another Embodiment of the Invention Next, a second embodiment of the present invention will be described.

FIG. 3 is a block diagram of the combined diversity receiving system according to the second embodiment. In this embodiment, the received electric field strength detection signals 3-1 and 3-2 and the weighting units 9a-1 and 9-9 are used.
Multiplication units 13-1 and 13-2 are provided between a-2. To the multiplication units 13-1 and 13-2, the received electric field strength detection signals 3-1 and 3-2 and the antenna abnormality detection signals 8-1 and 8-2 of the respective antenna systems are input, respectively. The antenna abnormality detection signal is set to 1 when the antenna is normal and to 0 when an abnormality occurs in the antenna. Multiplication unit 1
In 3-1 and 13-2, the received electric field strength detection signals 3-1 and 3-2
-2 is multiplied by the antenna abnormality detection signals 8-1 and 8-2, and the result is input to the weighting units 9a-1 and 9a-2. If the antenna has an abnormality, the received electric field strength detection signal is multiplied by 0, so that the weighting coefficient in the weighting section is 0. As a result, the phase synthesizing section 9c does not synthesize the phase information of the system and performs demodulation. It will not be used. When the antenna is normal, the received signal strength detection signal is simply multiplied by 1, so that a normal combining operation is performed.

[0017]

An advantage of the present invention is that deterioration of receiving sensitivity at the time of antenna failure can be minimized.

The reason is that if the antenna fails,
This is because, by removing the phase information obtained from the system in which the antenna has failed from the target of weighting synthesis, it is possible to synthesize and demodulate only the original signal information received from the normal antenna system without combining information due to noise. .

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of a combined diversity system according to the present invention.

FIG. 2 is a diagram illustrating an operation of weighting synthesis according to one embodiment of the present invention;

FIG. 3 is a block diagram of another embodiment of the present invention.

FIG. 4 is a block diagram of a conventional combining diversity system.

[Explanation of symbols]

 1-1, 1-2 Antenna 2-1, 2-2 Receiver 3-1, 3-2 Received electric field detection signal 4-1 and 4-2 IF signal 5-1 and 5-2 Phase detector 6-1 , 6-2 Phase information signal 7-1, 7-2 Antenna abnormality detection section 8-1, 8-2 Antenna abnormality detection signal 9 Weighting phase synthesis section 9a-1, 9a-2 Weighting section 9b-1, 9b-2 Switch section 9-c Synthesis section 10 Synthetic phase information signal 11 Demodulation section 12 Demodulation data 13-1, 13-2 Multiplication section

Claims (4)

[Claims] 1. A combined diversity receiving system having means for performing weighted combining, wherein a detection result of a means for detecting an antenna abnormality is used as the means for performing weighted combining. 2. A combined diversity receiving system having means for combining phases of at least two reception signals having different phases weighted by reception intensity from an antenna and a receiving means, wherein a detection result of the means for detecting an antenna abnormality is used. A combining diversity receiving method comprising means for stopping the phase combining of the system. 3. A means for stopping the phase synthesis of the system, using a detection result of the means for detecting an antenna abnormality,
3. The combined diversity receiving system according to claim 2, further comprising a switching unit that disconnects an input of the phase combining unit for the phase information of the system. 4. The combination according to claim 2, wherein the means for canceling the phase synthesis of the system includes a multiplication means for invalidating the weight of the reception signal of the system using a detection result of the means for detecting an antenna abnormality. Diversity reception method.