JPH04103227A - Rds receiver - Google Patents

Abstract

PURPOSE:To always attain desired preset channel selection operation by searching a broadcast wave having a same network recognition code so as to select a channel. CONSTITUTION:With a preset channel button 14 depressed, a frequency data is read from a preset channel memory 11 to receive a frequency in response to a read frequency data and a PI code is detected for a prescribed time to discriminate whether or not the reception PI code is detected. When the PI code is detected, the PI code stored in advance is compared with the reception PI code and when they are coincident, the channel selection is finished. In this case, it means that the channel selection frequency is automatically selected. Thus, the desired preset channel selection is simply implemented.

Description

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

[Prior Art] Generally, when a broadcast station broadcasts, information related to the program content is transmitted as data through multiplex modulation, and the receiving side can select the desired program content based on the demodulated data. There is a system RDS that can provide this service to radio listeners. This RDS data includes network identification code (PI), traffic information bureau identification code (TP), and traffic announcement identification code (TA).
), a program service name information code (PS) such as a broadcasting station name or network name, and a side wave number information code (AF) of a group of network stations broadcasting the same program.

(Problems to be Solved by the Invention) Incidentally, in the case of a vehicle-mounted receiver, the broadcast wave reception condition may deteriorate as the vehicle moves.

As a result, broadcast waves may not be received satisfactorily at the preset frequency. Therefore, in the RDS receiver, a method can be considered in which the frequency data (AF data) of a group of network stations broadcasting the same program is stored in advance in the memory of each recent channel. A large memory area is required to store data, and a controller with a larger RAM capacity than that used in conventional radio receivers must be used or a separate storage element must be provided, resulting in cost issues. The problem was that it was disadvantageous in terms of space.

This invention was made in order to solve the above-mentioned problem, and by ensuring a minimum memory area, even if the channel frequency data at the time of preset operation becomes inappropriate due to movement of the vehicle, the same network can be used. Recognition code (P
By searching for and selecting broadcast waves with the I code), it is possible to always perform the desired preset tuning operation.
The purpose is to obtain a DS receiver.

[Means for Solving the Problem] The RDS receiver according to the present invention includes a preset memory that stores frequency data and a network recognition code for each recent channel, reads frequency data from the preset memory in response to a read command, and reads the frequency data from the preset memory in response to a read command. means for receiving a frequency according to frequency data; means for sequentially changing the receiving frequency within the FM frequency range when the network recognition code of the received frequency cannot be received or does not match the stored network recognition code; means for rewriting the frequency in the corresponding precent memory to the frequency of the broadcast station when a broadcast station with the same broadcast content of a predetermined level or higher is received based on the network recognition code stored in the process of changing; This system is equipped with a means for receiving the original broadcasting station in the event that the original broadcasting station cannot be received.

[Function] In this invention, the frequency data is stored in the preset memory.
If you memorize the network recognition code at a time other than the evening, and the network recognition code received when selecting a preset channel is different from the stored one, or if the network recognition code cannot be received, seek within the FM broadcast frequency range and read the stored network. When a broadcast station with the same broadcast content at a predetermined level or higher is received based on the recognition code, the frequency in the corresponding preset memory is rewritten to the frequency of the broadcast station, and if the broadcast station with this condition cannot be received, the original broadcast is rewritten. Receive a station.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. 1st
The figure shows the configuration of the RDS receiver according to this embodiment, and the FM multiplex broadcast waves received by the antenna 1 are transmitted to the front end 2.
A desired station is selected, converted into an intermediate frequency IF, and then supplied to the F'M detection section 3. The front end 2 is controlled by a PLL circuit 6 including a programmable frequency divider, and a controller 10 sets a frequency division ratio and performs a channel selection operation. The detection output of the FM detection section 3 is sent to the multiplex demodulation circuit (MPX) via the noise canceller (NK) 4.
) 5, and in the case of stereo broadcasting, L (left) and R (
right) is separated into audio signals. Also, the FM detection section 3
The detected output is input to the RDS decoder 9 via the 57K) Iz bandpass filter 8, and is converted into distinguishable data by the controller 10. The controller 10 receives receiving station information (the above-mentioned PI, AF, PS, TP, T
A), and if the station currently being received is the same as the frequency data in the preset channel memory 11, the PI
PI code storage area (16 bits) corresponding to the code
Write it inside. Further, there is a level detection unit 7 that detects a received signal (electric field strength) based on the TF signal level, and an FM detection unit 3 that detects a signal when the IF signal level is a predetermined level or higher
A station detecting section 12 is provided which detects a receiving station and outputs a station detection signal when the detected output of the S curve characteristic is within a predetermined level range. The station detection signal output from the station detection section 12 is supplied to the controller 10. Further, the operation section 13 is provided with a preset channel button 14, and by pressing the preset channel button 14, the user can select a desired station.

Next, the operation when the preset channel button 14 is pressed to perform a channel selection operation will be described using the flowcharts shown in FIGS. 2(^) to 2(C). It is assumed that the frequency data and PI code desired by the user have already been written in the frequency data storage area and PI code storage area in the preset channel memory 11, as shown in Table 1.

When the preset channel button 14 in Table 1 is pressed, step S
At step t, a frequency corresponding to the frequency data stored in the preset channel memory is received, and step S
In step 2, the PI code is detected for a predetermined period of time to determine whether the received PT code can be detected. If it cannot be detected, the process advances to step S4, and if it can be detected, the pre-stored PI code and the received PI code are compared in step S3, and if they match, the process advances to step S14, where the channel selection operation is performed. end. If the stored PI code and the received PI code do not match, the process advances to step S4, and a first round PI search is performed. In step S4, it is determined whether the currently received frequency is the upper limit of the FM frequency range, that is, 1 0 8 MHz. If the frequency is the upper limit band edge, the lower limit band edge 9 7 MHz is determined in step S6. 5 MHz, and if it is not the upper limit band edge, it is one step higher in step S5 (
25Kl (z or 50Kl (z or 100K
Hz) Jl wave number is received. Next, in step S7, it is determined whether the received frequency matches the search start frequency, and if they do not match, it is determined in step S8 whether or not there is a station detection signal, and if there is a station signal, step In S9, it is determined whether or not the reception bell is at a predetermined level or higher, and if it is at a predetermined level or higher, it is determined in step SIO whether or not the received PI code and the stored PI code match. this is,
Search for a broadcasting station with the same broadcast content and good reception condition by repeating the above procedure until it is determined in step S7 that the station has returned to the original station, in other words, until it has made one round within the FM reception frequency range. It is. P in step 10
If the I codes match, that is, if the same broadcast content station is detected, the process proceeds to step Sll, the received frequency is rewritten in the corresponding frequency storage area in the memory, and the preset channel selection operation is completed. In this case, the selected frequency has been automatically switched. On the other hand, if the station returns to the original station in step S7, the process advances to step S12, where the PM code is detected again for a predetermined period of time, and if reception is possible, the stored PI code is rewritten to the received PI code in step S13, and the PI code is If the channel cannot be received, the channel preset tuning operation is ended in step S14 without rewriting the contents of the stored PI code. If the stored PI code is not rewritten, there will be no broadcast station with good reception of the same broadcast content in this area.

[Effects of the Invention] As described above, according to the present invention, by simply adding a storage area for each PI code to each preset channel, even if the vehicle moves and leaves the service area of the frequency stored in the preset channel memory, it is easy to do so. Therefore, a desirable preset channel selection operation can be performed at all times.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an RDS receiver according to the present invention, and FIGS. 2(A) to 2(C) are flowcharts showing the preset tuning operation of the RDS receiver according to the present invention. 2...Front end, 3...FM detection section, 5...
・Multiplexer demodulation circuit, 6... PLL circuit, 7.
...Level detection section, 9...RDS decoder, 10...
- Controller, 11... Preset channel memory, 2... Station reception section, ... Operation section.

Claims (1)

[Claims] In an RDS receiver that receives RDS broadcast waves including a network recognition code, there is a preset memory that stores frequency data and a network recognition code for each preset channel, and a preset memory that reads frequency data from the preset memory in response to a read command. means for sequentially changing the receiving frequency within the FM frequency range when the network recognition code of the received frequency cannot be received or does not match the stored network recognition code; and a process for changing the receiving frequency. means for rewriting the frequency in the corresponding preset memory to the frequency of the broadcast station when a broadcast station with the same broadcast content of a predetermined level or higher is received based on the network recognition code stored in the network recognition code; 1. An RDS receiver comprising means for receiving an original broadcast station when