Energy‐efficient orthogonal frequency division multiplexing scheme based on time–frequency joint channel estimation

Abstract

Time-domain synchronous orthogonal frequency division multiplexing (TDS-OFDM) enjoys the higher spectrum efficiency and faster synchronisation than the classical cyclic prefix OFDM (CP-OFDM). However, TDS-OFDM suffers from performance degradation especially under severely fading channels with long delays. To solve these problems, the authors propose an energy-efficient OFDM scheme called time-frequency-training orthogonal frequency division multiplexing (TFT-OFDM) based on the time-frequency joint channel estimation under the framework of compressive sensing (CS). The power of the guard interval (GI) in the proposed scheme can be reduced to achieve higher energy efficiency, which is infeasible for CP-OFDM. This method first utilises the time-domain pseudo noise sequence to acquire partial support information of the channel, and then some frequency-domain pilots are used for the exact channel estimation. Simulation results show that TFT-OFDM with CS can achieve much higher energy efficiency than the classical CP-OFDM, and outperforms the conventional OFDM schemes in both static and mobile environments. Moreover, for the channel with long delay spread, the TFT-OFDM scheme with CS can demonstrate robustness and much better performance than the conventional OFDM schemes. In this way, the TFT-OFDM scheme can use the same GI length for larger broadcasting coverage and hence further achieve higher energy efficiency.

Integrated power line and visible light communication system compatible with multi‐service transmission

“…However, VLC cannot be the information source directly and the only way for VLC to become the access point (AP) is to connect with the backbone network. Power line communication (PLC) [8, 9], which has a mature coded modulation scheme [10, 11], noise cancellation method [12–14], and channel estimation approach [15, 16], can be a good solution for this problem by combining PLC and VLC to a whole. The power line provides power to LEDs of the VLC system, and simultaneously acts as the signal source of VLC.…”

A positioning compatible multi-service transmission system based on the integration of VLC and PLC

“…Power line communication (PLC) [5], which has a mature coded modulation scheme [6] [7], noise cancellation method [8] [9], and channel estimation approach [10] [11], can be a good solution for this problem by the method of combining VLC and PLC to a whole. The power line provides power to LEDs of the VLC system, and simultaneously acts as the signal source of VLC.…”

Structured compressive sensing based narrowband interference mitigation for vehicular communications

“…The essential idea of the CS theory can be summarized that a "sparse" signal that has a high dimension can be recovered exactly from the measurement vector whose size is much smaller than that of the desired sparse signal [12]. CS has been applied to many areas such as channel estimation [13], [14]. The CS algorithms for signal recovery are studied by many researchers, such as the sparsity adaptive matching pursuit (SAMP) [15] and subspace pursuit (SP) [16].…”