Joint SCMA and waveform optimisation for WPDM-based logging cable telemetry systems under sampling clock offset

摘要

This study introduces sparse code multiple access (SCMA) and wavelet packet division multiplexing (WPDM) to logging cable telemetry systems (LCTSs). The authors study the feasibility of SCMA for LCTSs and provide a WPDM-based system model, as well as the associated optimal waveform design under sampling clock offset (SCO) via a genetic algorithm. The performance advantages of the designed scheme over the conventional WPDM and orthogonal frequency division multiplexing (OFDM) are demonstrated by both analytical and simulation methods. Numerical results show the performance of the SCMA-based mapping method over quadrature amplitude modulation in terms of improved spectral efficiency. Furthermore, the new scheme outperforms conventional WPDM and OFDM in bit error rate performance and transmission rate under SCO. Such advantages with the flexible design of basis functions make SCMA and WPDM a significant candidate for LCTSs.