N-Ary Alamouti Space-Time Block Coding With and Without Golden Codewords
Hongjun Xu, Narushan Pillay, Fengfan Yang · IEEE Access · 2023
Information is conveyed by either time, antenna, and/or frequency in the conventional modulation. In this paper, we propose a novel technique to convey information in Alamouti space-time block coding systems. In the proposed technique, the information is conveyed by one channel’s phase component with orderN. The proposed technique is referred to as 2 ×NrN-ary Alamouti-STBC (N-STBC), whereNris the number of receive antennas. TheN-STBC with Golden codewords (GCs) is further proposed to improve error performance at high signal-to-noise ratios (SNRs). Moreover, the proposedN-STBC with and without GCs still preserves the orthogonal transmission matrix of the Alamouti-STBC which retains the simple linear maximum-likelihood (L-ML) detection for quasi-static frequency-flat Rayleigh fading channels. The transmitted symbols can be directly estimated by use of the L-ML detection in theN-STBC with and without GCs. However, only the GCs are estimated by use of the L-ML detection inN-STBC with GCs. The signal detection subset based ML detection is further employed to detect the transmittedM-ary quadrature amplitue modulation (MQAM) symbols inN-STBC with GCs. The lower error probability bounds of theN-STBC with and without GCs are derived and validated by simulation results. As an example, the proposed 2 × 4 16QAM 16-STBC with GCs almost maintain the error performance of the conventional Alamouti-STBC with GCs at SNRs.