Modulation and demodulation method and device for GFDM signal

Abstract

The invention discloses a modulation and demodulation method and device for a GFDM signal. The modulation method comprises the following steps: carrying out channel coding on a binary signal to be transmitted, and carrying out grouping mapping to obtain a multi-system symbol; generating a corresponding ZC cyclic shift keying sequence after cyclic shift of the primitive ZC sequence according to the multi-system symbol; taking the ZC cyclic shift keying sequence as a spread spectrum code string, and adopting CCSK to carry out spread spectrum on binary data; carrying out serial-parallel conversion on the spread spectrum data to generate data blocks, and enabling column vectors of the data blocks to be a column of ZC cyclic shift keying sequences; taking the column vector of the data block as a sub-symbol of the GFDM; according to the primitive ZC sequence and the corresponding cyclic shift value, obtaining an IDFT form of the sub-symbol; and performing cyclic shift filtering on the IDFT form of each sub-symbol, and performing superposition to generate a baseband signal waveform. Aiming at the characteristics of low channel signal-to-noise ratio, large signal path fading, sensitivity to a signal peak-to-average power ratio and the like in satellite communication, the PAPR of a transmission signal is reduced, and the anti-interference performance is improved.

Description

technical field

[0001] The invention belongs to the communication field, and in particular relates to a method and device for modulating and demodulating GFDM signals. Background technique

[0002] Satellite communication has always been an important means of communication due to its wide-area coverage, but its limited transmission rate once limited its development in public communication. The reason is that due to the limitations of the platform and terminal volume, the satellite communication system is a power-limited system. Orthogonal Frequency Division Multiplexing (OFDM, Orthogonal Frequency Division Multiplexing) is one of the key technologies in 4G LTE and 5G NR. As a multi-carrier waveform technology, it greatly improves spectrum utilization, thereby improving network data transmission. The speed meets people's requirements for high-speed personal communication. However, when we apply OFDM to satellite communications, we have to face the problem of power backoff o...

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