JPH02213234A - Diversity receiver - Google Patents

Abstract

PURPOSE:To attain automatic tracking to a broadcast station broadcasting one and same program with less multi-path by detecting an error rate of a digital data corresponding to each antenna input and selecting an antenna input with less error rate. CONSTITUTION:An error rate detection means 6b of a main microcomputer 6 detects an error rate of an RDS code outputted from error detection/correction circuits 5a, 5b corresponding to antenna inputs A, B, and a comparison means 6c compares the error rate of the antenna inputs A, B. When a multi-path is large, since the error rate is larger, a selection means 6d of the main microcomputer 6 selects the antenna input A or B with leas error rate. Thus, the changeover to a station having much multi-path with the degree of signal intensity only is avoided.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a diversity receiver that has two or more antenna inputs and selects the antenna input with the least multipath. This invention relates to a diversity receiver using a data multiplexing system.

<Prior art> RDS (Radio Data System) is a system that searches for and switches to another broadcasting station with good reception that is broadcasting the same program.RDS is a digital data multiplexing system standardized by the European Broadcasting Union. system,
This method multiplexes and transmits various digital data (data that can be used for automatic selection of the best receiving station, traffic information identification, broadcasting station name display, etc.) on FM radio broadcasts. Such digital data includes frequency codes (AF codes) of broadcast stations that broadcast the same program, PI codes that indicate the same broadcast program (program) even if the broadcast stations are different, and RDS compatible receivers ( Using these digital data, the RDS receiver can automatically follow broadcast stations that have the same broadcast content and have good received field strength one after another.

<Problems to be Solved by the Invention> However, since the RDS receiver automatically follows based on judgment only based on electric field strength, there is a problem in that it switches to a station with many multipaths.

From the above, it is an object of the present invention to provide an RDS compatible diversity receiver that is equipped with two or more antennas and can automatically follow broadcasting stations with few multipaths. The purpose of the present invention is to provide an RDS-compatible diversity receiver that detects multipath using the functions of the RDS9 receiver and does not require a separate expensive multipath detection circuit.

<Means for solving r:s problem> -1- The problem described in J3 of the present invention is to detect an error rate of digital data in a digital data multiplexing system corresponding to each antenna input. detection means;
The present invention is achieved by: (1) comparing means for comparing the error rates of each detected antenna input; and (1) selecting means for selecting an antenna input with a lower error rate according to the comparison result.

<Operation> The error rate detection means detects the error rate of the digital data corresponding to the human power of each antenna, and the comparing means compares the 1 error rate of each antenna input detected by the digital data multiplexing system. , the selection means selects an antenna input with a low error rate according to the comparison result.

<Embodiment> Figure 1 is a block diagram of the main parts of the diaphragm receiver according to the present invention.
It has a chuyuna configuration.

1a is a l) r,, L circuit, which transmits a predetermined voltage signal necessary for receiving antenna input A to F M 7 r.
Output to J client 2a. FM Fund End 2
a receives the antenna power A input from the antenna A N T a based on the voltage signal, and generates a predetermined intermediate frequency signal (IF). 3a is an intermediate frequency amplifier which converts the intermediate frequency signal converted by the FM front end 2a to a predetermined level, and also increases the signal strength (signal amplifier) of the intermediate frequency signal indicating the receiving shape. value) S, is detected. 4a is an RDS decoder, which receives AN' sent at a predetermined transmission timing.
5a is an error detection/correction circuit that detects errors in RDS data such as AF codes and PI codes demodulated by the RDS decoder 4a for each group. Detect and correct errors while synchronizing.

Similarly to section L, for antenna power B, PLT, circuit 1b-FM front end 21), intermediate frequency amplifier 3b
, RDS decoder 4b-error detection/correction circuit 5b
ffi is provided.

6 is a main microcomputer that controls the overall operation of the diversity receiver compatible with RDS, and an intermediate frequency amplifier 3a.
, the signal strength SA manually input from 3b.

Means 6a for detecting the receiving state of antennas A, H based on SG, error rate based on corrected digital data RDA, RDO output from error detection/correction circuit 5a p 5 b of digital data multiplex system E,
, E, corresponding to each antenna human power A, B, an error rate detection means 61) for detecting each antenna human power A,
Comparison means 6c for comparing the error rates of antennas B, selection means 6d for selecting the antenna force A or B with the lowest error rate according to the comparison result, 7 is the selected antenna force Δ, 13 8 is a switching circuit that switches the intermediate frequency signal output to the subsequent stage according to the
TJX demodulates the intermediate frequency signal input from the intermediate frequency amplifier 3d or 3b into a stereo signal. 9
An amplifier (AMII) amplifies the 5 stereo signals according to a volume setting value (not shown). Reference numeral 10 denotes a speaker, which is activated by an amplifier 9 and outputs an audio signal.

The error rate detection means 6b of the main microcomputer 6 is.

The respective AF codes etc. superimposed on antennas A and B are sent to RDS decoders 4 a + 4, b,
The RD of the AF code etc. output from the error detection/correction circuit 5 a p 5 b is obtained through the L2 through the error detection/correction circuit 5 a g 5 b and its error rate is identified. Flags such as no error, corrected, uncorrected 01, etc. are attached to the S data, and by counting these flags, the error rate of the data can be detected. The error rate is correlated with multipath, and as the multipath increases, the error rate also increases. This is because as multipath increases, distortion occurs in the antenna forces A and B, and this distortion destroys the RDS data sent superimposed on the antenna forces A and H.

Therefore, the error rate detection means 6b functions as a multipath detection means.

The first step is as follows according to the flowchart of the process of the present invention shown in FIG.
The operation of the diagram will be explained.

First, the main microcomputer 6 outputs a predetermined voltage signal to the FM front ends 2a and 2b, and receives antenna inputs A and B (step 101). Note that the antenna inputs A and B are input as in the case of diversity reception. It does not matter whether the signals are from the same broadcasting station or from different broadcasting stations as in the case of automatic tracking using an RDS code.The signal strength SA output from the intermediate frequency amplifiers 3a and 3b, It is assumed that both S and S indicate good reception conditions.

Next, the error rate detection means 6b of the main microcomputer 6 detects
RDS output from error detection/correction circuits 5a and 5b
Detecting the error rate of the code corresponding to the antenna human forces A and H (step 102), comparing the error rates of the antenna human forces A and H by the comparing means 6c (step 103),
In other words, if the multipath is large, the error rate is also large, so the selection means 6d of the main microcomputer 6 selects
Select antenna power A or B, which has a lower error rate.

Therefore, if it is determined in step 103 that the error rate of the antenna input A is lower than that of the antenna input B, the main microcomputer 6 causes the switching circuit 7 to input the intermediate frequency signal output from the intermediate frequency amplifier 3a to the MPX 8 ( Step 104).

On the other hand, if the error rate of antenna human power B is lower than that of antenna human power A as determined in step 103.

The main microcomputer 6 connects the switching circuit 7 to the intermediate frequency amplifier 3.
The intermediate frequency signal output from b is input to the MPX 8 (step 105).

By monitoring multipath based on the error rate in this way, the station will not be switched to a station with a large number of multipaths based solely on signal strength.

<Effects of the Invention> According to the present invention, the error rate detection means for detecting the error rate of digital data corresponding to each antenna input in a digital data multiplexing system and the detected error rate of each antenna input are compared. Since a comparison means and a selection means for selecting an antenna input with a low error rate according to the comparison result are provided, it is possible to automatically follow the same program broadcasting station with less multipath using a digital data multiplexing system. Moreover, since a multipath detection circuit is not required, it has the excellent advantage of reducing the manufacturing cost of the receiver.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of main parts of a diversity receiver according to the present invention, and FIG. 2 is a flowchart of processing according to the present invention. 1a, 1b...PLL circuit. 2a, 2b...FM front end. 3a, 3b...Intermediate frequency amplifier. 4a, 4b...RDS decoder, 5a, 5b...error detection/correction circuit, 6...main microcomputer. Patent applicant Alvine Co., Ltd. agent Patent attorney Chiki Saito Figure 2

Claims (1)

[Claims] A diversity receiver that is compatible with a digital data multiplexing system, has two or more antenna inputs, and selects an antenna input with less multipath, comprising: an error rate of digital data in the digital data multiplexing system; an error rate detection means for detecting the error rate corresponding to each antenna input, a comparison means for comparing the error rate of each detected antenna input, and a selection means for selecting an antenna input with a lower error rate according to the comparison result. A diversity receiver comprising: