JP3017896B2 - Multiplex broadcast receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to multiplexing of RDS receivers and the like.
It relates to a broadcast receiver .

[0002]

2. Description of the Related Art Multiplex broadcasts implemented in Europe and the like, for example,
RDS receiver for receiving RDS broadcast is prevalent in and Europe, and a continue to follow updates according to the movement of the same program at different frequencies AF switching function. That is, the RDS data transmitted from the broadcast station after being multiplex-modulated includes AF list data which is a list of different frequency groups broadcasting the same program. The RDS receiver receives the target frequency from the AF list for a moment, checks its electric field strength with a signal meter (S meter), and determines a frequency having a stronger electric field strength as compared with the receiving station currently receiving. It is configured to be selected.

[0003]

However, in the above-mentioned conventional RDS receiver, since the reception band output from the S meter is wide, when interference such as adjacent interference is present, the electric field strength at a certain frequency is weak. However, there is a problem that the frequency is determined to be strong due to the influence of the interference and the frequency is switched to that frequency. Also, when adjacent interference increases in the receiving station,
There is such a problem that it is determined that the electric field strength of the receiving station is strong, and it is not possible to switch to another station on the AF list having a stronger electric field strength. An object of the present invention is to solve the above-mentioned problems of the conventional technology.

[0004]

Means for Solving the Problems] multiplex broadcasting receiver of the present invention in order to achieve the above object, a multi-data existence determining section determines the presence or absence of multiple <br/> data multiplex broadcasting being received, multi
When it is determined that there is no duplicate data, a reception level determining means for determining whether the reception level exceeds a predetermined value, and when the reception level exceeds a predetermined value, the reception level detection value of the multiplex broadcasting station being received is Detection level correction means for forcibly correcting downward, and switching means for sequentially switching stations in the list based on the AF list after the correction to switch multiplex broadcast reception to a better reception station. .

[0005]

The multiplexed data presence / absence determining means determines whether or not multiplexed broadcasting is being received.
It determines the presence of multiple data, when it is determined that no multiplex data, 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 forcibly corrects the reception level detection value of the multiplex broadcasting station being received downward, and after this correction, the switching means sequentially switches the stations in the list based on the AF list. Switch to switch to multiplex broadcast 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 the RDS receiver. The broadcast received by the FM tuner 1 is converted into audio from a speaker via an audio controller 2 and an audio amplifier 3 and output.

[0007] The electric field strength of the broadcast received by the FM tuner unit 1 is input to the CPU 4 as an S meter,
It is configured so that digital conversion is performed inside to check the electric field strength. The RDS data received by the FM tuner 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 an RDS flag and can judge that RDS is present.

The CPU 4 also executes R
A for switching to the same program broadcasting station with higher electric field strength based on the AF list included in the DS data
An F switching operation is performed.

In addition to the above configuration, this embodiment is configured so that correct AF switching can be performed even if there is adjacent interference or the like. It is known that the retrievable electric field strength of the RDS data is currently about 15 to 30 dB. Also, when there is a strong adjacent station, the sensitivity decreases due to the AGC characteristic of the tuner, so that the ability to acquire RDS data also decreases. Utilizing the above, the CPU 4 determines whether or not the RDS data has been obtained based on the RDS flag, and determines whether or not the S meter indicates a value larger than the true value a (V) of the electric field from which the RDS data can be obtained. The judgment is made. Then, the RDS data cannot be obtained and the S meter is a (V)
If it is larger than this, it can be determined that there is an interfering station,
At this time, the S meter is forcibly regarded as 0 and the AF switching operation is performed.

[0010] Even if the AF switch is performed by the above-mentioned operation, there is a possibility that the station may return to the original station having the interference. That is, the switching comparison operation must be performed instantaneously, and it is difficult to determine whether or not the RDS data can be acquired in a short period of time. There is. Therefore, when the CPU 4 determines that there is an interfering station as described above, the CPU 4 puts a special mark on the frequency in the AF list and lowers the priority for switching to the 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 a switching operation (step 12, if there is the same program broadcasting station with a large electric field strength (step 13), switch to that station (step 20). If there is no such station, return to step 10. In step 11, RDS
If there is no data, the S meter voltage value a (V) at the purely RDS data acquirable electric field strength level is compared with the S meter (step 14). wo is determined to be correct and a switching operation is performed (step 15). It is determined whether or not there is a better station (step 16). If so, switching to that station is performed (step 20). If it is determined in step 14 that the S meter is equal to or larger than a,
The switching operation is performed by forcing the value of the meter to be 0 (step 17). If there is the same program broadcasting station having a large electric field strength (step 18), the original frequency in the AF list is marked to lower the priority (step 1).
9), switching to that station is performed (step 20). If there is no such station, return to step 10.

According to the above-described embodiment, not only the electric field strength but also the AF including the reception status depending on the degree of noise is used.
Since the switching operation is performed, it is possible to accurately follow a station having a large electric field height. Also, the original station where the interference occurred is marked and the priority is lowered, so that it is possible to prevent returning to that station.

[0013]

As described above, the multiplex broadcast receiving apparatus of the present invention is
The transceiver is a multiplex data presence / absence determining means for determining the presence / absence of multiplex data of the multiplex broadcast being received, and a reception level determining means for determining whether or not the reception level exceeds a predetermined value when it is determined that there is no multiplex data. Detection level correction means for forcibly correcting the reception level detection value of the multiplex broadcasting station being received downward when the reception level exceeds a predetermined value, and sequentially switching the stations in the list based on the AF list after the correction. And a switching means for switching multiplex broadcast reception to a better receiving station, so that the same program broadcasting station can be tracked with high accuracy even if there is adjacent interference or the like.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one 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 section, 4: CPU, 5: RDS decoder, 6: display.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H03J 5/00-7/28 H04B 1/16

Claims (1)

(57) [Claims] 1. A multiplexed data presence / absence determining means for determining the presence / absence of multiplexed data of a multiplex broadcast being received, and a reception level determination for determining whether or not the reception level exceeds a predetermined value when it is determined that there is no multiplexed data. Means, detection level correction means for forcibly correcting the reception level detection value of the multiplex broadcasting station being received downward when the reception level exceeds a predetermined value, and sequentially changing the stations in the list based on the AF list after the correction. It switched multiplex broadcast receiver, characterized in that it and a switching means for switching the multiplexed broadcasting receiving the better reception station.