Symbol Detection Using Discrete Prolate Spheroidal Sequences under the Plasma Sheath Channel

The plasma sheath has a serious impact on the propagation of electromagnetic waves, resulting in the radio blackout problem in aerospace communications. Existing studies have shown that the coherence time of the plasma sheath channel can be as low as 0.1μs, which is smaller than the symbol period in aerospace telemetry communications. However, the traditional symbol detection method based on correlation filters only uses the orthogonality of transmission symbols, without considering the channel variation within one symbol period. In this paper, a new symbol detection scheme is proposed under the high-dynamic plasma sheath channel. Firstly, the discrete prolate spheroidal sequences are used to expand the dynamic channel. Then, based on an analysis of the log-likelihood ratio, a linear combination detection scheme is proposed, which has a simple form and is suitable for symbol detection under the plasma sheath channel. In particular, we show that the performance of communication systems under the plasma sheath channel can be improved by spreading the signal dimension. Finally, simulation results are carried out based on the shock tube experimental data, showing that the proposed detection scheme has better performance compared with the correlation-based detection method.