A Time-Domain Precoder to Improve the Bandwidth Efficiency of TD-LTE Systems

This paper designs a new precoding for an OFDM system without cyclic prefix (CP), to achieve the same function with CP used in CP-OFDM system. After the analysis of CP-OFDM system, this paper constructs a modulation matrix; on this basis, introduces memory characteristics, as well as symbols feedback, and designs a time domain precoding (TDP) module. By adding the TDP module into TD-LTE link, its bit error ratio (BER) performance decreases slightly, compared to the CP system; however, due to the new system, it does not need to send CP signals; therefore, it eliminates redundancy, so the bandwidth efficiency increases.