JPH03265227A - Receiver - Google Patents

Abstract

PURPOSE:To easily select an optimum reception system by employing fuzzy inference calculation to discriminate the reception states of respective reception systems respectively based on a reception signal, comparing the result of discrimination mutually and outputting the selective signal of a best reception system. CONSTITUTION:Plural reception systems 2-1-2-n process reception signals inputted from antennas ANT1-ANTn connected respectively and output reception signals. A discrimination means 3 discriminates the reception state of each reception system by a fuzzy inference operation based on the reception signal of each reception system respectively, compares the result of discrimination as to each reception system mutually to output the selective signal of a best reception system. A selective means 4 outputs the reception signal of the best reception state based on the selective signal of the discrimination means 3 while selecting them selectively. Thus, a selective switching circuit 3 selects the reception system by taking the reception state of each reception system into consideration totally to attain more accurate reception system selection.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a receiver, and particularly to a radio receiver using a selective diversity reception method.

[Conventional technology]

Conventionally, as a reception method that uses multiple antennas to obtain the optimal reception condition, dipersity (DIMERSIT7) has been used.
The reception method is known. Diperity reception methods include a selection diversity method, a switching diversity method, and the like. The selection diversity method will be explained below as an example.

In the selection diversity method, as shown in FIG. 6, a selection device SEL selects a plurality of receiving systems R, R, ...2R connected to antennas ANTI, ANT2, ..., ANTn, respectively. This is a method in which the output of the receiving system with the best reception condition is used as the received signal.

FIG. 7 shows a detailed block diagram of a conventional selection diversity type receiver. The receiver can be roughly divided into two receiving systems, a selector 300 for selecting the output of one of these two receiving systems, and a diversity controller 4 for controlling this selector 300.
It consists of 00 and.

The first receiving system is connected to the antenna ANTI and the RF
(Radio Frequency) A first receiving circuit 100 that processes the signal A1 and outputs the received signal BY, and detects a received level signal (for example, an S meter level signal) corresponding to the electric field strength and outputs the first received level signal. It has a first reception level detection circuit 102 that performs the following. The first receiving circuit 100 includes a front end, an intermediate frequency amplifier, a wave detector, etc. (not shown). The 1st level detection circuit 102 detects the received level signal S1 from the output signal of the latter stage of the intermediate frequency amplifier or detector, for example.

The second receiving system includes a second receiving circuit 200 and a second receiving level detecting circuit 202 similarly to the first receiving system.

In the first receiving system, the I-th receiving circuit 100 takes in the RF signal Al from the antenna ANTI and outputs the received signal B1 to the selector 300. The first reception level detection circuit 102 detects the reception level from, for example, an output signal of a subsequent stage of a detector (not shown) of the first reception circuit 100, and outputs the detection signal to the diversity controller 400 as a first reception level signal S1. do.

Similarly, the second receiving circuit 200 receives R from the antenna ANT2.
Take in the F double signal A and send the received signal B2 to the selector 30
Output to 0. Also in the second receiving system, the detection circuit 20
2 detects the second reception level signal S2 from the reception circuit 200 and outputs it to the diversity controller 400.

The diversity controller 400 outputs a selector control signal E for selecting one of the reception systems to the selector 300 based on each reception level signal S 13 . The selector 300 selects one of the received output signals based on the selector control signal E and outputs it as a selected received output signal. Thereby, the selector 300 outputs an output signal corresponding to the reception system with the best reception condition.

In this way, as shown in FIG. 8, the receiver selects the receiving system with the better reception condition from the two receiving systems, and always maintains the good reception condition. In FIG. 8, the receiving state of the receiving system R1 is shown by a solid line, the receiving state of the receiving system R2 is shown by a broken line, and the thick line indicates the selected receiving system. That is, it shows that the receiving systems R, R, R1, . . . are selected in this order as time passes.

In the conventional example described above, the diversity controller 400 performs control based on the reception level signal, but there is also a system that performs control using a noise level signal instead of the reception level signal.

[Problem to be solved by the invention]

The problem with the conventional diversity receiver described above is that the selection of the receiving system is not necessarily performed accurately.

That is, since the diversity controller 400 generates the selector control signal E based on the received level signals S1 and S2 or based on the noise level signal, both the received signal and the noise level are used as the reference. Never. As a result, if the reception level is high, problems such as being selected even when the noise signal level is high will occur, and the optimal reception system will not necessarily be selected.

In view of the above problems, an object of the present invention is to provide a receiver that can easily and stably select a receiving system with the best reception condition.

[Means to solve the problem]

FIG. 1 shows a diagram explaining the principle of the present invention.

The receiver 1 selects which one of the plurality of receiving systems 2-1 to 2-4 connected to each of the plurality of antennas ANTI to ANTn and the plurality of receiving systems 2-1 to 2 has the best reception state. a selection switching circuit 3 that selectively switches and outputs the output signal of the receiving system, and the selection switching circuit 3 determines the reception state of each receiving system by fuzzy inference calculation based on the received signal of each receiving system. a determining means 3 for outputting a selection signal of the best reception system by comparing the determination results for each reception system; and a selection unit for selectively switching and outputting the reception signal of the best reception system based on the selection signal. Means 4.

[Effect]

According to the present invention, the plurality of receiving systems 2-1 to 2-1 process input signals from the respective antennas ANTI to ANTn and output received signals.

The determining means 3 determines the reception status of each receiving system by fuzzy inference calculation based on the received signal of each receiving system, and compares the determination results for each receiving system with each other to determine the selection signal of the best receiving system. Output.

The selection means 4 selectively switches and outputs the received signal of the best receiving system based on the selection signal.

Therefore, the selection switching circuit 3 can select a receiving system by comprehensively considering the reception status of each receiving system, and can select a receiving system more accurately.

〔Example〕

Next, each embodiment of the present invention will be described with reference to the drawings.

First Embodiment A first embodiment of the present invention will be described with reference to FIG. FIG. 2 shows a case where there are two receiving systems.

Receiver equipment 0 is roughly divided into a first receiving system connected to ANTI, a second receiving system connected to ANT2, and a first receiving system connected to ANT2.
, a first receiving system that selects one of the outputs of the second receiving system.
It consists of a selector 41 and a diversity controller 30 that controls the first selector 41.

The first receiving system is an RF doubler A from the antenna ANTI.
A first receiving circuit 11 that processes I and outputs a received signal B1.
, a first reception level detection circuit 12 that detects a reception level signal (for example, an S meter level signal) corresponding to the electric field strength and outputs a first reception level signal S1, and a reception output signal C.
a first noise level detection circuit 13 that detects the signal level of noise included in the noise level signal N1 and outputs a first noise level signal N1;
It has . The first receiving circuit 1 includes a front end, an intermediate frequency amplifier, a wave detector, etc. (not shown). The first level detection circuit 2 detects the received level signal S1 from, for example, the output signal of the latter stage of the intermediate frequency amplifier or detector.

Like the first receiving system, the second receiving system includes a second receiving circuit 21, a second receiving level detection circuit 22 that outputs a second receiving level signal S2, and a second receiving level detecting circuit 22 that outputs a second noise level signal N. It has a noise level detection circuit 23.

The diversity controller 30 has a CPU and a memory, and uses its built-in program and membership function to perform fuzzy inference calculations based on the first received level signal S and the first noise level signal N1, and obtains the first fuzzy inference result. Signal F
A first fuzzy inference unit 31 outputs 1, and performs a fuzzy inference calculation based on the second reception level signal S2 and second noise level signal N2, and outputs a second fuzzy inference result signal F2 of 0.
and a second fuzzy inference section 32 that outputs a second fuzzy inference result signal FSF2, and further includes a second fuzzy inference section 32 for selecting one of the first or second receiving system based on the first and second fuzzy inference result signals FSF2. a comparison section 33 that outputs a selector control signal E;
It is configured with.

The comparison unit 33 includes, for example, a comparator.

The first selector 41 selects the received signal B1 or the received signal B2.
is switched and output as a reception output signal C based on the selector control signal E.

Next, the operation will be explained.

In the first receiving system, the first receiving circuit 11 processes the RF signal A1 from the antenna ANTI and outputs the received signal B1. The first reception level detection circuit 12 detects the reception level from, for example, an output signal of a subsequent stage of a detector (not shown) of the first reception circuit 11, and outputs a first reception level detection signal Sl.
Output. A first noise level detection circuit 3 detects the level of a noise signal included in the received signal B1 and outputs a first noise level detection signal N1.

Similarly, in the second receiving system, the second receiving circuit 21 processes the RF doubler A input from the antenna ANT2 and outputs the received signal B2. Second reception level detection circuit 2
2 detects a reception level from, for example, an output signal of a subsequent stage of a detector (not shown) of the second reception circuit, and outputs a second reception level signal S2. The second noise level detection circuit 23 detects the level of the noise signal included in the received signal B2,
A second noise level detection signal N2 is output.

The diversity controller 30 has a first reception level signal S1, a second reception level signal S1, a second noise level signal N1, and a second noise level signal N1.
2 is input. The first fuzzy inference result signal uses the first reception level signal S, the first noise level signal N, and the first
A fuzzy inference result signal F1 is output. More specifically, first, the membership function for the first reception level signal Sl and the reception level signal level (FIG. 3(a))
The grade of the first reception level signal is determined from the above. Next, the grade of the first noise level signal is determined based on the first noise level signal N1 and the membership function for the noise level signal level (FIG. 3(b)). Furthermore, the grade of the reception condition is determined by the minimax method etc. based on the grade of each of these signal levels (
3(C)), the first fuzzy inference result signal F1 corresponding to the grade is output. Similarly, the second fuzzy inference unit 32 uses the second reception level signal S1 and the second noise level signal N2 to output a second fuzzy inference result signal F2 based on a preset ship function. . The comparison unit 33 compares these fuzzy inference result signals F
1F2, a selector control signal E is output for selecting the first or second reception system with better reception condition.

Based on the selector control signal E, the first selector 4t selectively converts the received signal of one of the receiving systems into the received output signal C.
Output as .

As described above, according to this embodiment, fuzzy inference is performed based on the reception level signal and noise level signal of each reception system, and the fuzzy inference results of each reception system are compared to select the reception system. Therefore, it is possible to easily select the optimal reception system without setting strict conditions for optimal reception in advance.

Second Embodiment A second embodiment of the present invention will be described with reference to FIG. FIG. 4 shows a case where there are two receiving systems. The same parts as in the first embodiment will be described with the same reference numerals.

The difference from the first embodiment is that the comparator 33 has a hysteresis characteristic so that the reception system is not switched frequently when the reception level signal changes drastically, and the comparator 33
The present invention is also equipped with a hysteresis characteristic changing section 34 that can change the hysteresis characteristic based on the received level signal.

For example, as shown in FIG. 5(a), the comparison unit 33 equipped with the hysteresis characteristic changing unit 34 includes a Schmitt circuit 36 that includes an operational amplifier 35, a resistor R, and a resistor R2, and is capable of switching a feedback resistor R3, and a selector control circuit. a switching instruction section 37 that outputs a switching instruction signal G for selectively switching the feedback resistor R3 based on a reception level signal corresponding to the reception system selected based on the signal E;
The switch 38 selectively switches the feedback resistor R3 based on the switching instruction signal G.

Next, the operation will be explained.

In the first receiving system, the first receiving circuit 11 processes the RF signal A1 input from the antenna ANTI and outputs signals such as the received signal B1. First reception level detection circuit 1
2 detects the reception level from the input signal, and
A received level detection signal S1 is output. The first noise level detection circuit 13 detects the level of a noise signal included in the received signal B1, and outputs a first noise level detection signal N1.

Similarly, in the second receiving system, the second receiving circuit 21 processes the RF doubler AI input from the antenna AVIT2 and outputs the received signal B2. The second reception level detection circuit 22 detects the reception level from the input signal and outputs a second reception level signal S2. The second noise level detection circuit 23 detects the level of the noise signal included in the received signal B2, and outputs a second noise level detection signal N.

The diversity controller 30 has a first reception level signal S, a second reception level signal S, a second noise level signal N1, and a second noise level signal N.
2 is input. The first fuzzy inference section 31 uses the first reception level signal S1 and the first noise level signal N1 to output a first fuzzy inference result signal F1 based on a preset membership function. The second fuzzy inference section 32 uses the second reception level signal S1 and the second noise level signal N2 to output a second fuzzy inference result signal F2 based on a preset membership function.

The switching instruction section 37 outputs a switching instruction signal G that selectively switches the feedback resistor R3 based on the reception level signal corresponding to the selector control signal E. This results in
The feedback resistor R3 of the Schmitt circuit 36 is selectively switched by the changeover switch 38, and as a result, the hysteresis voltage vH (see FIG. 5(b)) becomes vH=R2/(R2+R3)×(vl-vl).

Here, ■i is the positive power supply voltage, ■.

is the negative power supply voltage.

Therefore, if the feedback resistor R3 is selected to increase the hysteresis voltage when the reception condition is not good, the selector control signal E output from the comparator will not switch frequently, and stable reception operation will be achieved. This means that you can do it.

Based on the selector control signal E, the first selector 41 selectively converts the received signal of one of the receiving systems into the received output signal C.
Output as .

As explained above, according to this embodiment, when the reception condition is not good, the hysteresis voltage is increased,
The configuration is such that the reception system cannot be easily switched, and when the reception condition is good, the hysteresis voltage is reduced to immediately select a more optimal reception system.

Therefore, when the received signal level changes rapidly, it is possible to reduce the occurrence of switching noise caused by unnecessary switching, and to easily and stably select a receiving system with a good reception condition. Hold stable.

In the second embodiment described above, the feedback resistance of the Schmitt circuit is switched based on one received level signal, but it is also possible to configure the switching to be performed using the average value of each received level signal. . It is also possible to weight each reception level signal and use their average value. Further, although the feedback resistor is switched like a switch, it is also possible to switch the feedback resistor continuously.

In each of the above embodiments, only the case where there are two receiving systems has been described, but the present invention can also be applied to a case where there are three or more receiving systems.

〔Effect of the invention〕

According to the present invention, since the reception status of each reception system is determined by fuzzy inference calculation, the reception status can be easily and comprehensively judged without setting strict conditions in advance for selecting the optimal reception system. The optimal reception system can be selected stably.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the principle of the present invention, Fig. 2 is a block diagram of the first embodiment, Fig. 3 is an explanatory diagram of the membership function, Fig. 4 is a block diagram of the second embodiment, and Fig. 5 is a block diagram of the first embodiment. FIG. 6 is an explanatory diagram of a comparison section, FIG. 6 is an explanatory diagram of a diversity receiver, FIG. 7 is an explanatory diagram of a conventional diversity receiver, and FIG. 8 is an explanatory diagram of receiving circuit selection operation. 1...Receiver 2 □~2-7...Receiving system 3...Selection switching circuit 5...Selection control signal 10.20...Receiver 11...First receiving circuit 12... - First reception level detection circuit 3...First noise level detection circuit 21...Second reception circuit 22...Second reception level detection circuit 23...Second noise level detection circuit 30... Dipercity controller 31...first
Fuzzy inference section 32... Second fuzzy inference section 33... Comparison section 34... Hysteresis characteristic changing section 35... Operational amplifier 36... Schmitt circuit 37... Switching instruction section 38... Changeover switch 41...First selector 42.43...Second selector 50151...Soft mute circuit 61...Emute driver 62...Second mute driver A, A,...RF times Signals ANTI to 8NTn... Antenna B, B2... Received signal C... Received output signal E... Selector control signal Fl... First fuzzy inference result signal F2... First fuzzy inference result Signal G...Switching instruction signal N1...First noise level signal N,...Second noise level signal B1...First reception level signal B2...Second reception level signal 1: Receiver

Claims (1)

[Claims] 1. A plurality of receiving systems connected to each of a plurality of antennas, and an output signal of one of the plurality of receiving systems having the best reception condition is selectively switched and outputted. In the receiver, the selection switching circuit determines the receiving state of each receiving system by fuzzy inference calculation based on the received signal of each receiving system, and performs the determination for each receiving system. 1. A receiver comprising discriminating means for comparing the results with each other and outputting a selection signal of the best receiving system. 2. In the receiver according to claim 1, the determining means:
a fuzzy inference calculation unit that performs fuzzy inference calculation based on the field strength detection signal or noise detection signal extracted from the received signal of each receiving system and outputs the inference result signal; a comparison unit that outputs a selection signal for selecting a reception system with a good reception condition;
A receiver characterized by comprising: 3. The receiver according to claim 1 or 2, wherein the determining means has a hysteresis characteristic. 4. The receiver according to claim 3, wherein the determining means, based on the output signal of the receiving system,
A receiver comprising a hysteresis characteristic changing section that changes the hysteresis characteristic during the comparison. 5. The receiver according to claim 4, wherein the hysteresis characteristic changing section changes the hysteresis characteristic based on the field strength detection signal. 6. The receiver according to claim 5, wherein the hysteresis characteristic changing section changes the hysteresis characteristic based on an average value of the field strength detection signals of each of the receiving systems.