A Novel Scheme for Space-Time Block Coding with Variable Transmit Diversity Gain in Time-Frequency-Shift Keying Systems
一种可变分集增益的空时/时频调制编码新方案

A novel scheme for unitary space-time block coding with variable transmit diversity gain is proposed for TFSK (Time-Frequency-Shift Keying) systems. Each modulated TFSK symbol is divided into two orthogonal sub-symbols, and the new scheme is constructed by differently combining the sub-symbols with the different transmit diversity gain able to be achieved by noncoherent processing at the receivers. The results of computer simulation show that the new scheme has advantage of anti-flat-fading over Alamouti space-time block coding and space-time frequency-shift keying, and ST-TFSK systems with two diversity gain enjoy the superior coding rate and the inferior anti-fading performance to the ones with four diversity gain, which approve the theoretical analysis