Channel searching device and method for broadcasting receiver

Abstract

The invention discloses a channel searching device and method for a broadcasting receiver. The channel searching device comprises a channel switching module, an automatic gain control module, an automatic frequency control module, a received signal strength estimation module, a received signal quality estimation module, a demodulated signal quality estimation module and a judgment module, wherein the output end of the channel switching module is connected with the input end of the automatic gain control module; the output end of the automatic gain control module is connected with the input end of the automatic frequency control module; the output end of the automatic frequency control module is connected with the input ends of the received signal strength estimation module, the received signal quality estimation module and the demodulated signal quality estimation module; and the output ends of the received signal strength estimation module, the received signal quality estimation module, the demodulated signal quality estimation module and the automatic frequency control module are connected with the judgment module. The channel searching device and method for a broadcasting receiver can preferably reflect the strength and quality of the wanted signal in a channel and the quality of the demodulated signal, maintain the optimal gains input from radio frequency to demodulation, improve the estimation accuracy on the strength, quality and signal-to-noise ratio of the received signal, improve the estimation accuracy on the number of the quality burrs of the demodulated signal, and realize rapid and effective channel searching.

Description

technical field [0001] The present invention relates to a communication device and method, and in particular to a device and method in a broadcast receiver. Background technique [0002] Broadcast receivers are mainly used to receive FM and AM signals. Among them, the channel search module is a very important device. The early receivers only used the received signal strength RSSI as the criterion for the quality of the station. This method is applicable to the situation that there is no external interference and the noise and interference of each station inside the receiver are consistent. However, there are many external interferences in the FM and AM broadcast frequency bands, and the interference and noise of different channels are also very different, and the performance of the receiver itself in different channels is also different, which requires better criteria. Recently, many receivers have introduced some signal quality-related criteria, and these methods are eith...

AI Technical Summary

Problems solved by technology

[0004] A major problem with existing products is that when there is a lot of air noise in the channel, the received signal strength RSSI cannot reflect the strength of the useful signal in the channel

[0005] Another problem with existing products is that when the channel signal is very weak, although the signal-to-noise ratio of the demodulated output is high enough, the signal-to-noise ratio of the intermediate frequency signal may be very poor, so the counting results obtained by intermediate frequency counting cannot be accurate. reflect signal quality

[0006] Another problem with existing products is that after changing channels, the gain from RF to demodulation input is not optimal, and the channel frequency may also be inaccurate, which also affects the accuracy of received signal strength RSSI and IF counting

[0007] Another problem with existing products is that under different frequency offsets, even if the signal-to-noise ratio of the input signal is the same, the counting results of the intermediate frequency counting will vary greatly, resulting in this indicator not being able to accurately and effectively reflect the signal quality of the channel.

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