Two-Dimensional Information Transmission Method in DSSS

In this paper, a two-dimensional information transmission method based on k step-complex spread spectrum (KS-CSS) is proposed. The aim is to solve the contradiction between the bandwidth and processing gain of a traditional direct-sequence spread spectrum (DSSS) channel, and to achieve better system performance (such as by obtaining higher processing gain and higher bandwidth utilization). Using the multi-domain characteristics of DSSS signals, based on the time–frequency characteristics of a DSSS, the code-domain characteristics are further combined. The KS-CSS method calculates the control coefficients such as modulation order, PN code group, and conversion time. Thus, dependence mapping for additional two-dimensional data transmission is established. Then, the spread spectrum pseudo-code is mapped and processed with one-dimensional data. Theoretical analysis and simulation results show that the time–frequency domain characteristics of the KS-CSS signal are consistent with those of traditional DSSS signals. However, the information transmission rate can be increased by more than 100%, and the bit error rate of data can be significantly improved. The high-speed transmission performance and low bit error rate of the KS-CSS method can provide a theoretical basis and technical reference for high-performance spread spectrum communication.