JPH06169235A - Rds receiver - Google Patents

Abstract

PURPOSE:To allow the RDS receiver to select an excellent reception station regardless of the presence of disturbing noise by discriminating the presence of disturbance when no RDS is acquired and an S meter output has a prescribed output or over and setting the S meter output to be zero thereby executing the AF switching operation. CONSTITUTION:When RDS data are inputted to a CPU 4, an RDS flag is set and then the presence of RDS is discriminated. Then the CPU 4 discriminates whether or not the RDS data are acquired based on the RDS flag and also discriminates whether or not the S meter indicates a value larger than a true electric field at which the RSD data are able to be acquired. It is decided that a disturbance station exists, when the RDS data is not obtained and the S meter indicates a value layer than a true electric field at which the RSD data are able to be acquired. In this case, the S meter is regarded forcibly to be 0 and the AF switching operation is executed. Furthermore, when the presence of a disturbing station is discriminated, the CPU 4 gives a special mark to the frequency in an AF list to place lower priority of switching to the station and to select an excellent station.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an RDS receiver.

[0002]

2. Description of the Related Art RDS receivers are widely used in Europe and the like, and have an AF switching function of updating and following the same program of different frequencies as it moves. That is, the RD sent from the broadcasting station after being multiplexed and modulated.
The S data includes AF list data that is a list of different frequency groups broadcasting the same program.
The RDS receiver momentarily receives the target frequency from the AF list, checks the electric field strength with a signal meter (S meter), and selects a frequency with a stronger electric field strength as compared with the currently receiving receiving station. Is configured to select.

[0003]

However, in the above-described conventional RDS receiver, since the reception band output by the S meter is wide, when an interference such as an adjacent interference occurs, the electric field strength of a certain frequency is weak. However, there is a problem that it is judged to be strong due to the influence of the interference and the frequency is switched to that frequency. Also, when adjacent stations increase in reception,
There is a problem that it is determined that the station receiving the signal has a strong electric field strength, and it is impossible to switch to another station in the AF list having a stronger field strength. The present invention aims to solve the above-mentioned problems of the prior art.

[0004]

In order to achieve the above object, the RDS receiving apparatus of the present invention uses an RDS of an RDS broadcast being received.
RDS data presence / absence determining means for determining the presence / absence of DS data, reception level determining means for determining whether or not the reception level exceeds a predetermined value when it is determined that there is no RDS data, and the reception level exceeds a predetermined value. Sometimes receiving RD
Detecting level correction means for forcibly correcting the reception level detection value of the S broadcasting station, and after the correction, the stations in the list are sequentially switched based on the AF list to make a better receiving station RD.
A switching means for switching S reception is provided.

[0005]

The RDS data presence / absence determining means determines presence / absence of RDS data of the RDS broadcast being received, and when it is determined that there is no RDS data, the reception level determining means determines whether or not the reception level exceeds a predetermined value. . When the reception level exceeds a predetermined value, the detection level correction means is receiving the RDS.
The reception level detection value of the broadcasting station is forcibly corrected downward, and after this correction, the switching means sequentially switches the stations in the list based on the AF list to switch RDS reception to a better receiving station.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an RDS receiving apparatus, in which a broadcast received by an FM tuner unit 1 is converted into a voice and output from a speaker via an audio control unit 2 and an audio amplifier unit 3.

The electric field strength of the broadcast received by the FM tuner unit 1 is input to the CPU 4 as an S meter, and the CPU 4
It is configured to be digitally converted internally to check the electric field strength. The RDS data received by the FM tuner unit 1 is decoded by the RDS decoder 5 and input to the CPU 4 as RDS data. When the RDS data is input, the CPU 4 sets the RDS flag and can determine the presence of RDS.

The CPU 4 also executes R by a predetermined program.
Based on the AF list included in the DS data, switching to the same program broadcasting station with a higher electric field strength A
The F switching operation is performed.

In addition to the above construction, this embodiment is constructed so that correct AF switching can be performed even when there is an adjacent interference. It is known that the obtainable electric field strength of RDS data is currently about 15 to 30 dB. In addition, when there is a strong adjacent station, the sensitivity decreases due to the AGC characteristic of the tuner, so the RDS data acquisition capability also decreases. Utilizing the above, the CPU 4 determines whether or not the RDS data is obtained by the RDS flag, and whether or not the S meter shows a value larger than the true value a (V) of the electric field for which the RDS data can be obtained. It is designed to judge. And, RDS data cannot be obtained, and S meter is a (V)
If it is larger than that, it can be determined that there is a jamming station,
At this time, the S meter is forcibly regarded as 0 and the AF switching operation is performed.

Even if the AF switch is performed by the above operation, there is a possibility of returning to the original disturbing station. That is, the switching comparison operation must be performed in an instant, and it is difficult to determine whether RDS data can be acquired in a short time. Therefore, the S meter determination described above is difficult, and there is a possibility of switching back. There is. Therefore, when it is determined that there is an interfering station, the CPU 4 puts a special mark on the frequency in the AF list to lower the priority for switching to that station.

The operation will be described with reference to FIG. RDS reception is performed (step 10), and it is determined whether or not there is RDS data (step 11). AF if there is RDS data
Based on the list, the stations in the list are sequentially switched and received to perform the switching operation (step 12, if there is the same program broadcasting station having a high electric field strength (step 13), switch to that station (step 20). If there is no such station, return to step 10. RDS in step 11.
If there is no data, the S meter voltage value a (V) at the electric field strength level at which RDS data can be obtained is compared purely with the S meter (step 14). If wo is correct, switching operation is performed (step 15), it is determined whether or not there is a better station (step 16), and if not, the process returns to step 10. If so, the station is switched to that station (step 20). When it is determined in step 14 that the S meter is a or more, S
The switching operation is performed by forcibly regarding the value of the meter as 0 (step 17). If there is the same program broadcasting station with a high electric field strength (step 18), the original frequency in the AF list is marked to lower the priority (step 1).
9) Then, switch to that station (step 20). If there is no such station, return to step 10.

According to the embodiment described above, the AF including not only the electric field strength but also the reception situation depending on the degree of noise is included.
Since the switching operation is performed, it is possible to accurately follow a station with a high electric field altitude. Also, since the original station that has been disturbed is marked and the priority is lowered, it is possible to prevent returning to the station.

[0013]

As described above, the RDS receiving apparatus of the present invention has the RDS data presence / absence determining means for determining the presence / absence of RDS data of the RDS broadcast being received, and the reception level thereof when it is determined that there is no RDS data. And a detection level correction means for forcibly correcting the reception level detection value of the receiving RDS broadcasting station downward when the reception level exceeds a predetermined value.
After the correction, the switching means for sequentially switching the stations in the list based on the AF list to switch the RDS reception to a better receiving station is provided, so that the same program broadcasting station can be accurately followed even if there is adjacent interference. There is an effect that can be.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of one embodiment of the present invention.

[Explanation of symbols]

1: FM tuner section, 2: Audio control section,
3: audio amplifier unit, 4: CPU, 5: RDS decoder, 6: display.

Claims (1)

[Claims] 1. RDS data presence / absence determining means for determining the presence or absence of RDS data of an RDS broadcast being received, and reception level determination for determining whether or not the reception level exceeds a predetermined value when it is determined that there is no RDS data. Means, a detection level correcting means for forcibly correcting the reception level detection value of the RDS broadcasting station being received when the reception level exceeds a predetermined value, and the stations in the list sequentially in accordance with the AF list after the correction. An RDS receiving apparatus comprising: a switching unit that switches and switches RDS reception to a better receiving station.