Time-domain synchronous OFDM space-frequency coding time-frequency combination channel estimating method

Abstract

The estimation method for time-frequency joint channel in TDS-OFDM space-frequency code comprises: 1) the transmission antennas of T1 and T2 executes space-frequency diversity code; 2) for some rule, alternative transmitting the TPS information after error correction coding carried on OFDM sub-carrier; 3) taking time-frequency joint channel estimation with time-domain PN sequence and TPS information; 4) space-frequency decoding to recovery transmission information. This invention changes little to original transmitter system, simple, fast and accurate, and supports soft-failure to improve reliability.

Description

technical field [0001] The invention belongs to the field of digital information transmission, and more specifically relates to a time-frequency joint channel estimation method of space-frequency coding (Space-frequency) in a Time Domain Synchronous OFDM (TDS-OFDM) system. Background technique [0002] An important basis for terrestrial digital TV broadcasting or mobile communication is the propagation of radio waves, which propagate from transmitting antennas to receiving antennas in a variety of ways, including free space waves, tropospheric reflection waves, ionospheric waves, and ground waves. Free space waves, also known as direct waves, propagate along a straight line and are used for satellite and external space communications, as well as ground-line-of-sight propagation (for example, between two microwave towers). The troposphere, 10 miles above the Earth, is a heterogeneous medium whose reflective index decreases with altitude. Between 40 and 400 miles in the atmos...

AI Technical Summary

Problems solved by technology

In 1998, Tarokh introduced it in "Tarokh V, Seshadri N, and Calderbank A. Space-time codes for high data rate wireless communications: performance criterion and code construction. IEEE Trans. on Information Theory, 1998, 44(2): 744-765" The concept of space-time trellis coding (STTC) is designed, which designs channel coding and antenna diversity as a whole. This method can theoretically obtain the maximum gain, but it needs to change the design of the entire transmitting system and the decoding of the receiving end. The complexity is also greatly increased

Shortly thereafter, Alamouti proposed a space-time block code (STBC) scheme in his classic paper "Alamouti S.A simple transmit diversity technique for wireless communications. IEEE Trans.onSelect Areas in Communications, 1998, 16(8): 1451-1458" , although the coding gain of STTC cannot be obtained, the coding structure and decoding algorithm are very simple, and the diversity gain can also be obtained

Images