Signal demodulation system and signal demodulation method

Abstract

The embodiment of the invention relates to the field of communication, and discloses a signal demodulation system and demodulation method, and the system comprises a signal synchronizer which is usedfor calculating a frequency offset estimation value and a frame synchronization estimation result according to an inputted frequency modulation signal and a local signal, a frequency offset eliminatorwhich is used for eliminating estimated residual frequency offset in the frequency modulation signal according to the frequency offset estimation value to obtain a first signal, and an adaptive modulation coefficient coherent demodulator which is used for outputting a demodulation result of the frequency modulation signal according to the first signal and the frame synchronization estimation result, wherein the modulation coefficient of the signal synchronizer and the modulation coefficient of the adaptive modulation coefficient coherent demodulator are preset to be the same coefficient value, and different coefficient values correspond to different demodulation frameworks. According to the invention, the modulation coefficient of the signal synchronizer and the modulation coefficient ofthe adaptive modulation coefficient coherent demodulator are preset to be the same coefficient value, and different coefficient values correspond to different demodulation frameworks, so that coherentdemodulation is realized, and the influence caused by the changed modulation coefficient is eliminated.

Description

technical field [0001] The embodiments of the present invention relate to the communication field, and in particular to a signal demodulation system and demodulation method. Background technique [0002] The FSK (Frequency Shift Keying) signal is a signal used for high-speed data transmission. The transmitting end of the FSK modulated signal usually sets a range for the FSK modulation coefficient. For example, the FSK modulation coefficient of the BT architecture is usually set to 0.28-0.35, and the FSK modulation coefficient of the BLE architecture is usually set to 0.45-0.55. The usual receiving end cannot perform coherent demodulation for changing modulation coefficients. During the demodulation process of FM signals, the residual frequency offset in the FM signal needs to be considered. The existence of these residual frequency offsets makes the demodulation process of FM signals not coherent demodulation. , thus affecting the demodulation result of the FM signal. In t...

AI Technical Summary

Problems solved by technology

The usual receiving end cannot perform coherent demodulation for changing modulation coefficients. During the demodulation process of FM signals, the residual frequency offset in the FM signal needs to be considered. The existence of these residual frequency offsets makes the demodulation process of FM signals not coherent demodulation. , thus affecting the demodulation result of the FM signal

In the existing schemes, non-coherent demodulation methods are mostly adopted, such as split filter envelope detection method, zero-crossing detection method, etc., but these methods have low frequency band utilization and are difficult to accurately detect

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