A low-complexity demodulation method for continuous phase modulation based on threshold decision

Abstract

The invention belongs to the technical field of wireless communication, and discloses a low-complexity demodulation method for continuous phase modulation based on threshold judgment; including: (1) symbol mapping; (2) continuous phase modulation; (3) converting modulated signals into frequency (4) Transform the frequency domain signal into a time domain signal; (5) Send the modulated signal; (6) Receive the signal containing noise; (7) Separate multiple users to obtain the time domain signal of each user; (8) Based on Continuous Phase Modulation and Demodulation of Decision Threshold. The present invention adopts the method based on the threshold judgment, calculates the phase similarity between the received signal and the local reference signal, sets the threshold, reduces the grid number of the matched filter and Viterbi decoding, can greatly reduce the complexity of demodulation, overcomes the The problem of high demodulation complexity in the prior art enables the present invention to effectively reduce the complexity of the receiver and increase the practicability of the system.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, in particular to a low-complexity demodulation method for continuous phase modulation based on threshold judgment. Background technique [0002] At present, the closest prior art: In the field of mobile communication, limited available spectrum resources and complex wireless transmission environment are two restrictive factors in the field of wireless communication. The requirements of these communication systems for modulated signals are characterized by high requirements on spectral characteristics and insensitivity to nonlinear distortion. Continuous phase modulation (Continuous Phase Modulation, CPM) signal is a general term for a type of constant envelope modulation signal, compared with multi-ary phase shift keying (M-ary Phase Shift Keying, MPSK), it occupies a narrower bandwidth and has sidelobe attenuation Faster, with better spectral efficiency and power efficiency. At ...

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Problems solved by technology

However, the shortcomings of this method are: this method cannot maintain a constant envelope signal, has high requirements on the power amplifier, and the system spectrum utilization rate and power utilization rate are low

However, this method still has disadvantages: this method can only reduce the number of matched filters, but cannot reduce the number of grid searches in Viterbi decoding, and it destroys the structure of the optimal receiver, and the system performance is poor

[0006] (1) A continuous phase multi-carrier modulation method in the prior art cannot maintain a constant envelope signal, and has high requirements for power amplifiers, and the system spectrum utilization rate and power utilization rate are low

[0007] (2) The existence of two continuous phase modulation frequency domain equalization modulation and demodulation methods in the prior art can only reduce the number of matched filters, cannot reduce the grid search number of Viterbi decoding, and destroys the structure of the optimal receiver, poor system performance

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