JP3234542B2 - Radio data receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio data receiver, and more particularly to a radio data receiver compatible with RDS (Radio Data System).

[0002]

2. Description of the Related Art In Europe, an RDS for multiplexing and transmitting various data during program broadcasting of a general broadcasting station has already been provided.
(Radio Data System) has been put to practical use. In this system, various digital data can be superimposed on an FM radio broadcast signal and transmitted. The message transmitted by the digital data is the program identification code (PI code) of the currently received FM broadcast.
, Broadcast station name code (PS code), broadcast station frequency list during the same program broadcast (AF data), program content identification code (P
(TY code), broadcast state identification code (DI code), code that identifies whether music is being broadcast or conversation is being broadcast
(M / S code), identification code of traffic information broadcasting station (TP code), identification code during traffic information broadcasting (TA code), and the like.

On the other hand, conventional receivers are often provided with a function of automatically searching for a receivable station and an auto-preset function of memorizing the frequency, but the same function is set within the entire receivable frequency range. In many cases, there are a plurality of frequencies broadcasting a program, and thus there is a problem that these are duplicated and preset. For example, the problem described above occurs when the same broadcasting station has a plurality of transmitting stations and can receive signals from at least two of them at the same time.

In order to avoid such a problem, for example, Japanese Patent Application Laid-Open No. 4-126403 (H03J 7/18, H04B 1/06, H04B
The invention of 1/16) includes an RDS-compatible receiver
A method is disclosed in which a broadcast station having the same PI code as a preset broadcast station is not preset by using a code (program identification code).

[0005]

However, the above-mentioned Japanese Patent Application Laid-Open
In the invention of Japanese Patent Application Laid-Open No. 4-126403, there is a problem that it takes time since it is necessary to perform all processes such as broadcast station detection and RDS data demodulation for all broadcast station frequencies.

The present invention has been made in view of the above circumstances, and when one broadcast station is preset, its AF data (broadcast station frequency list during the same program broadcast) is stored, and An object of the present invention is to provide a radio data receiver capable of shortening a time required for an auto preset process by skipping a frequency without performing a search.

[0007]

SUMMARY OF THE INVENTION A radio data receiver according to the present invention includes a receiving means for receiving a radio broadcast wave including list data indicating the frequency of another broadcasting station which is broadcasting the same program; Data demodulation means for extracting and demodulating list data from the received radio waves, search means for automatically searching for frequencies of receivable stations in a predetermined order within a receivable frequency range, and receivable searched by the search means Frequency data storage means for storing the frequency of the station; and list data storage means for receiving and storing list data included in the radio wave searched by the search means from the data demodulation means, wherein the search means stores the list data at the time of the search. It is characterized in that the frequency stored in the means is skipped.

In such a radio data receiver of the present invention, the frequency stored in the list data storage means is skipped during the search by the search means, so that the time required for searching the entire receivable frequency range is reduced. Is done.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings showing the embodiments. FIG. 1 is a block diagram showing a configuration example of a radio data receiver according to the present invention.

In FIG. 1, reference numeral 1 denotes an antenna. The broadcast wave received by this antenna 1 is
In the front end 2, a station desired by the user is selected, and the frequency of the selected station is changed to the intermediate frequency conversion circuit 3.
And then supplied to the detection circuit 4.

The front end 2 is constituted by, for example, a PLL synthesizer system using a PLL (Phase Locked Loop) circuit 5 including a programmable frequency divider. A microcomputer 6 controls the frequency division ratio of the programmable frequency divider. Thus, a channel is selected.

The detection output from the detection circuit 4 is supplied to a multiplex demodulation circuit 7 and demodulated into an audio signal. If the broadcast wave being received is a stereo broadcast,
It is separated into audio signals of both L / R channels.

The detection output of the detection circuit 4 is also supplied to a radio data demodulation circuit 8. The radio data demodulation circuit 8 extracts and demodulates a radio data signal. As shown in the schematic diagram of FIG. 2, the radio data output from the radio data demodulation circuit 8 is composed of 4 blocks (104 bits), and each block is 26 bits. The 26-bit data of each block consists of a 16-bit (m0 to m15) information word and a 10-bit (c0
To c9) check word and other (offset word). Of these, 16 bits of information bits
The above various information including AF data is included.

The radio data output from the radio data demodulation circuit 8 is supplied to an error detection / correction circuit 9 where an error detection and an error correction of an information word are performed based on a check word, and then the microcomputer 6 outputs the data. Given.

The output of the PLL circuit 5 is a broadcast station detection circuit.
Intermediate frequency (IF: Intermediate Frequenc
y) The signal level and frequency are checked. At this time, when the level of the IF signal is equal to or higher than a predetermined value and the frequency is within a predetermined range, the broadcast station detection circuit 10 determines that a receiving station exists.

The microcomputer 6 determines the result of the determination by the broadcast station detection circuit 10 and the error detection / correction circuit 9
Input the radio data corrected by the
In addition to performing channel selection by controlling the frequency division ratio of the programmable frequency divider, it also functions as search means for performing auto-preset processing as described later. Further, the microcomputer 6 is provided with a frequency data memory 61 and an AF list memory 62 for the automatic preset processing.
However, these memories can be realized by using an appropriate area of an internal memory provided in a general microcomputer.

Reference numeral 11 denotes an operation unit for various operations (tuning, volume adjustment, etc.) by the user, and reference numeral 12 denotes a display unit for displaying a tuning frequency and the like.

Next, the procedure of the auto-preset processing executed by the microcomputer 6 will be described with reference to the flowchart of FIG.

First, when the auto-preset processing is started, the microcomputer 6 initializes the counter I to "1" and the reception frequency f to 87.50 MHz.
(Step S11). In this embodiment, the reception frequency f is 50 kHz in the range of 87.50 MHz to 108.00 MHz.
This is the z (0.05 MHz) step.

After the initialization of the counter I and the reception frequency f is completed, the microcomputer 6 controls the PLL circuit 5 to receive the current reception frequency f, and the broadcast station transmitting the current reception frequency f The presence or absence is determined (step S12). This determination is made by the broadcast station detection circuit 10 based on whether or not the level of the IF signal at the current reception frequency f is equal to or higher than a predetermined value.

If there is no broadcasting station transmitting the current reception frequency f (“NO” in step S12), the microcomputer 6 proceeds to step S19 described later, If there is a broadcasting station transmitting ("YES" in step S12), the microcomputer 6 presets the reception frequency f in the preset number P (I) of the frequency data memory 61 corresponding to the counter I (step S12). S13), the counter I is incremented by "1" (step S14).

Next, the microcomputer 6 checks whether or not the value of the counter I has exceeded the maximum preset number M (step S15), and if it has exceeded it ("YES" in step S15).
"), The auto-preset processing ends. If the value of the counter I does not exceed the maximum preset number M, the microcomputer 6 determines whether or not AF data is included in the reception wave of the current reception frequency f. (Step S16) If no AF data is included (Step S16)
If “NO” in S16), the process proceeds to step S19 described later.

If the AF data is included in the above step S16 ("YES" in step S16), it means that there is another frequency broadcasting the same program as the current reception frequency f. The microcomputer 6 adds and stores a frequency higher than the current reception frequency f among those frequencies in the AF list memory 62 (step
S17) If a frequency lower than the current reception frequency f is already stored in the AF list memory 62, it is deleted (step S18).

Next, the microcomputer 6 increments the current reception frequency f by 50 kHz (0.05 MHz) (step S19), and the result is the upper limit of the reception frequency of 108.00 MHz.
It is determined whether or not the number has exceeded (step S20). If the received frequency f after the increment exceeds 108.00 MHz
("YES" in step S20), the microcomputer 6
Terminates this auto-preset processing, but if it has not exceeded ("NO" in step S20), the microcomputer 6 checks whether or not the incremented reception frequency f is stored in the AF list memory 62. (Step S21).

If the received frequency f after the increment is stored in the AF list memory 62 (step S21)
"YES"), the microcomputer 6 returns the process to the above-described step S19. Received frequency f after increment
If is not stored in the AF list memory 62 ("NO" in step S21), the microcomputer 6 returns the processing to the above-described step S12, and repeatedly executes the processing from step S12 onward for the reception frequency f after the increment. Is done. That is, when the reception frequency f after the increment is stored in the AF list memory 62, the reception frequency f
With regard to, the processes from step S12 to step S18 described above are skipped.

According to the auto-preset processing of the radio data receiver of the present invention, for example, when a certain broadcasting station broadcasts the same program by superimposing radio data at 90.00 MHz and 95.00 MHz, First, in step S19, when the processing returns to step S12 after the reception frequency f after the increment becomes 90.00 MHz, the reception frequency f
= 90.00 MHz is preset to the preset number P (n) and stored in the frequency data memory 61. In this case, AF data exists in step S16 (95.00MHz, 107.00MHz)
, And each is stored in the AF list memory 62.

When the receiving frequency f becomes 95.00 MHz in step S19, this 95.00 MHz
Since it is determined that MHz has already been stored in the AF list memory 62, the process returns to step S19, and the reception frequency f is further incremented by 0.05 MHz. Accordingly, steps S12 to S12 relating to the reception frequency f = 95.00 MHz
The processing of S18 will not be performed.

The processing in step S18 is stored in the AF list memory 62 when the auto-preset processing has been performed before, and if the auto-preset processing is not determined to be receivable in this auto-preset processing, extra data is stored. Needed to erase the.

Furthermore, in the above embodiment, the search is performed in 0.05 MHz steps from the lower end (87.50 MHz) of the entire receivable frequency range, but the search may be performed in any other order. Needless to say.

[0030]

As described in detail above, according to the radio data receiver of the present invention, there is provided a receiving means for receiving a radio broadcast wave including list data indicating another broadcast station frequency which is broadcasting the same program. A data demodulating means for extracting and demodulating list data from radio waves received by the receiving means, a searching means for automatically searching for frequencies of receivable stations in a predetermined order within a receivable frequency range, and a searching means. Frequency data storage means for storing the frequencies of the receivable stations searched; list data storage means for receiving and storing list data contained in radio waves searched by the search means from the data demodulation means; In this case, the frequencies stored in the list data storage means are skipped, so that all the receivable frequencies Time required for the scope of the search is reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration example of a radio data receiver according to the present invention.

FIG. 2 is a schematic diagram of radio data received by the radio data receiver of the present invention.

FIG. 3 is a flowchart showing a procedure of an auto preset process by the radio data receiver of the present invention.

[Explanation of symbols]

 3 Intermediate frequency conversion circuit 4 Detection circuit 5 PLL circuit 6 Microcomputer 8 Radio data demodulation circuit 10 Broadcast station detection circuit 61 Frequency data memory 62 AF list memory

Claims (1)

(57) [Claims] 1. A receiving means for receiving a radio broadcast wave including list data indicating another broadcasting station frequency which is broadcasting the same program, and extracting and demodulating the list data from the radio wave received by the receiving means. Data demodulation means, search means for automatically searching for frequencies of receivable stations in a predetermined order within a receivable frequency range, and frequency data storage means for storing frequencies of receivable stations searched by the search means A list data storage unit for receiving the list data included in the radio wave searched by the search unit from the data demodulation unit and storing the list data, wherein the search unit is stored in the list data storage unit when searching. A radio data receiver characterized in that it is adapted to skip frequencies.