Separation method and receiving device of digital broadcasting analog-to-digital (A/D) signal at frequency modulation (FM) broadcast band

Abstract

The invention provides a separation method and receiving device of a digital broadcasting analog-to-digital (A/D) signal at a frequency modulation (FM) broadcast band. The separation method comprises the following steps: adding two neighboring vector signals in in-band-on-channel (IBOC) A/D mixed signals S, eliminating component of a digital signal dm to obtain x<2m>+x<2m>+1, and then obtaining amplitude and phase, wherein, the nth component of x<2m> and x<2m>+1 can be those of phase modulation signals ej alpha and ej beta; solving parameters theta and delta to obtain x<2m> and x<2m>+1; and restoring the digital signal dm. In the method, the designed antenna of the receiving device is sequentially connected with a tuning module, an A/D converter, a digital down converter (DDC) and a re-sampling module; output of the re-sampling module is switched in an A/D signal separation module with a concrete calculation program to obtain corresponding analog FM signals and digital signals; the signals are respectively accessed to a digital signal demodulator/decoder of an analog FM receiver; and finally an analog sound signal, a digital audio signal and a data signal which are sent from a sending end are obtained finally. The separation method has the advantages of good A/D signal separation effect, capability of eliminating mutual interferences and reliable performance and is easy to achieve.

Description

(1) Technical field [0001] The invention belongs to the technical field of digital audio broadcasting, and in particular relates to a method for separating analog-to-digital signals of FM broadcast frequency band digital broadcasting and a receiving device. (2) Background technology [0002] AM (Amplitude Modulation, AM) broadcasting began in 1920, and FM (Frequency Modulation, FM) broadcasting began in 1940. In my country, from the 1950s to the 1960s, medium and short-wave broadcasting developed rapidly. In the 1970s, FM broadcasting rose rapidly, and the sound quality of broadcasting was significantly improved. FM broadcasting has been widely used. Although with the rapid development of TV, Internet, and mobile communication network, traditional audio broadcasting has once become a secondary important media method, and its development speed is far behind other major communication methods, but audio broadcasting has its specific application environment and Demand, is still...

AI Technical Summary

Problems solved by technology

Using COLT and other methods of the above-mentioned hybrid digital broadcasting can restore and separate the analog FM signal, and then eliminate the analog FM signal from the analog-digital mixed signal to obtain a digital FM signal, but at this time the residual analog FM signal becomes the background of the digital signal Noisy, recovered digital signal does not work well

[0014] Therefore, in the real TIBOC digital-analog audio broadcasting system with the same frequency and the same band, the spectrum of the analog main FM signal and the digital modulation signal completely overlap. Using the traditional FM separation technology, the demodulated analog FM signal will become a part of the OFDM signal, and The residual noise power from the analog FM signal will be much greater than the power of the OFDM signal, so that the recovered digital modulation signal cannot meet the requirements of a certain signal-to-noise ratio, affecting the receiving quality of the digital modulation signal

At the same time, the interference of the digital modulation signal to the analog main frequency modulation signal makes the analog main frequency modulation signal unable to recover accurately

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