JPH04189033A - Rds receiver - Google Patents

Abstract

PURPOSE:To surely select a most excellent station in one switching by comparing reception levels of all frequencies in one and same network station group and selecting a reception frequency after the best station is detected. CONSTITUTION:An audio mute section 12 is set and a PI data and a frequency of a broadcast station received at present are stored and a reception signal level and a frequency are written in a best station memory of a memory 11. A head address(n=1) of AF data f1-f2 stored in advance in the AF memory of the memory 11 is read and the station of the frequency is received. The reception signal level is detected and it is compared with a signal level stored in the best station memory, and when the signal level of the reception station is higher than the reception level of the best station memory, the frequency and the signal level of the reception station are written in the best station memory and when the signal level of the reception station is not higher than the reception level of the best station memory, the best station memory is not rewritten. When the detection of all frequency is finished, the frequency data of the best station memory is received, the audio mute section 12 is reset to release the audio mute.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radio data system (RDS) receiver implemented in Europe.

[Conventional technology]

Conventionally, when a broadcast station broadcasts, information related to the program content is transmitted as data using multiplex modulation, and the receiver side can select the desired program content based on the demodulated data. There is an RDS system that provides services. This RDS data includes network identification code PI, traffic information station identification code TP, traffic announcement identification code TA, program service name information code PS such as broadcasting station name and network name, and network stations broadcasting the same program. There are frequency information codes such as AP.

By the way, in the case of a vehicle-mounted receiver, the condition of the broadcast wave being received may deteriorate as the vehicle travels. However, in the case of RDS broadcasting, it is possible to obtain AP data of a group of network stations broadcasting the same program, so by storing this AP data in memory, it is possible to ) or other stations on the same network that are larger.

[Problem to be solved by the invention]

In the above-mentioned conventional device, an audible discomfort may occur in the receiving state when selecting stations within the same network station, and a receiving frequency selection method for an RDS receiver that reduces this discomfort is proposed in Japanese Patent Application No. 63-259040. proposed by No. This method uses A from the current receiving station and the current receiving station.
After detecting the presence of the receiving station, the received signal t\ with one station from the frequency group of other same network stations given by the P data is compared, and the presence of the receiving station is detected again. Since the method involves switching from station to station with a high reception level, there was a possibility that switching would be repeated several times until the station was switched to the best station in the area where the vehicle was driving.

This invention was made in order to solve the above-mentioned problems, and provides an RDS receiver that can reliably select the best station by switching operation of -degrees, and that does not cause any discomfort to the listener. The purpose is to obtain.

[Means to solve the problem]

The RDS receiver according to the present invention includes a second memory that stores the frequency and signal level of a receiving station, and a same network that is stored in the first memory including the signal level of the frequency stored in the second memory. means for comparing the signal levels of all frequencies of the station group, updating the signal level with the frequency of the station with the highest signal level, and storing the level in a second memory;
means for comparing the network recognition codes of the two stations when the frequency of the station initially stored in the second memory and the frequency of the station finally stored in the second memory do not match; In addition to receiving the frequency of the station
means for receiving the frequency of the station first stored in the second memory when the compared network recognition codes do not match; 2 is provided with an audio mute means for cutting off audio output while switching the reception frequency to the station first stored in the memory of No. 2.

[For production]

In this invention, the signal levels of all frequencies of the same network station group are compared, and the frequency and signal level of the station with the highest signal level are stored in the second memory and received. If this new receiving frequency and the first receiving frequency do not match and the network recognition codes also do not match, the switching is made to the first receiving frequency again. Also, the audio is muted until the station with the highest reception level is received and again while switching to the first receiving station.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. 1st
The figure is a block diagram of an RDS receiver according to this embodiment. The front end 2 selects a desired station from the FM multiplex broadcast wave received by the antenna, converts it into an intermediate frequency TF, and then supplies it to the FM detection section 3. The front end 2 is controlled by a PLL circuit 6 including a programmable frequency divider, and is configured to perform channel selection by setting a frequency division ratio using a controller 1o. F
The detection output of the M detection section 3 is a noise canceller (N, K) 4.
The signal is supplied to a multiplex demodulation circuit (MPX)-5 via a stereo broadcast, and is separated into L (left) and R (right) channel audio signals, which pass through an audio mute section 13 and become audio output. Audio mute section 13
is controlled on and off by the controller 10. Also, F
The detection output of the M detection section 3 is input to the RDS decoder 9 via the 57 KHz bandpass filter 8, and is converted into data that can be determined by the controller 10. The controller 10 takes in information of the receiving station (PI, TP, TA, PS, AF, etc.) and stores it in the memory 11. Level detection section 7
detects the received No. 4 level (different strength) based on the IP signal level, and the detected received No. 4 level is supplied to the controller 10.

Next, the automatic channel selection operation executed by the controller 10 in the RDS receiver having the above configuration will be explained with reference to the flowchart shown in FIG. First, in step S1, the audio mute unit 12 is turned on, in step S, the PI data and frequency of the broadcasting station currently being received are held, and in step S, the reception level and reception frequency are stored in the memory 1.
Write in the corresponding area in the best station memory No. 1 as shown in Table 1. f, is the reception frequency, and ■, is the signal level when f is received.

In steps 34 to S6 of Table 1, the first address (n=]) of the AF data f1 to f stored in advance in the AF memory of the memory 11 as shown in Table 2 is read out, and the station of that frequency is read out. actually received.

In step S8 of Table 2, the level of this reception No. 4 is detected, and this signal level is compared with the signal level stored in the best station memory, and the signal level of the receiving station is higher than the reception level of the best station memory. If higher, the frequency and signal level of the receiving station are written in the best station memory in step SI. If it's not expensive,
Do not rewrite the contents of the best station memory. The above procedure is repeated until n is reached (S, .), in other words until all comparisons of frequency groups f, ~f, in the AP memory have been made. If n is the final value in step S1, that is, if the detection of all frequency groups is completed, the frequency data in the best station memory is received in step S311, and the process proceeds to step S1.
At step f, the audio mute section 12 is turned off to cancel audio muting. In step S12, it is determined whether or not the frequency in the best station memory matches the original received frequency. If they are different, it is determined in step S14 whether or not the PI code matches. Continue to receive the best stations.

If the PI codes do not match, step S1. Turn on the audio mute section 12 to cut off the audio output, and then proceed to step S.
At step 17, the original reception frequency is received, and at step S, the audio mute is canceled. Also, if they match in step S13, it means that there is no other station with better reception conditions on the same network frequency, and the best station is continued to be received without checking whether the PI codes match. .

[Effects of the Invention] As described above, according to the present invention, the reception levels of all frequencies of the same network station group are compared and the reception frequency is switched after detecting the best station. You can reliably select the best station by switching between. Furthermore, since the audio output is not cut off during the comparison of the network recognition codes, the audio mute time is shortened, and the audible discomfort can be reduced.

[Brief explanation of the drawing]

FIGS. 1 and 2 are a block diagram and a flowchart showing the operation of the RDS receiver according to the present invention. ■...Antenna, 2...Front end, 3...
FM detection section, 5...Multiplex demodulation circuit, 7...
Level detection section, lO...controller, I 109.
Memory, l2...Audio mute section.

Claims (1)

[Claims] A receiving means for receiving an RDS broadcast wave including a frequency information code and a network recognition code of the same network station group, a first memory for storing the frequency information code of the same network station group, and a level for detecting the level of the received signal. a detection means, a holding means for holding the frequency of the receiving station and a network identification code, a second memory for storing the frequency and signal level of the receiving station, and a signal level of the frequency stored in the second memory. Means for comparing the signal levels of all frequencies of the same network station group stored in the first memory, and updating and storing the frequency and signal level of the station with the highest signal level in the second memory. a means for comparing the network recognition codes of the first station stored in the second memory and the frequency of the last station stored in the second memory when they do not match;
means for causing the receiving means to receive the frequency of the station stored in the second memory, and means for causing the receiving means to receive the frequency of the station first stored in the second memory if the compared network recognition codes do not match; A sound that cuts off audio output until the station finally stored in the second memory is received, and also cuts off the audio output while changing the receiving frequency to the frequency of the station that was first stored in the second memory. An RDS receiver characterized by being equipped with a mute means.