Performance Analysis of Soft Spread Spectrum Based on Walsh Orthogonal Sequence

Aiming at the problem of poor correlation and insufficient anti-interference ability of soft spread spectrum base code based on cyclic shift in complex environment, this paper proposes an improved method based on Walsh orthogonal spread spectrum. Different from the traditional cyclic shift method based on base code, the system uses Walsh code as the base code. Walsh code is an orthogonal code with zero cross-correlation, which can effectively reduce the bit error rate. By using the specific bits of the original information to map the corresponding rows of the Walsh matrix for spread spectrum, the correlation of the base code is enhanced to increase the maximum number of errors allowed in the correlation reception. This helps to better correct transmission errors in the RS decoding process, restore raw data, and improve the anti-interference performance of communication systems in complex electromagnetic environments. The simulation results show that the communication system based on Walsh coding shows good bit error rate performance in multipath fading channel under complex electromagnetic environment, and the bit error rate of the system is better than that of the traditional communication system based on cyclic shift spread spectrum in the channel environment with interference. Especially in low SNR conditions, this advantage is more obvious.