A Minimum Mean-Square-Error (MMSE) Decoder for Quasi-Orthogonal Space–Time Block Code

Abstract

The quasi-orthogonal space–time block code (QO-STBC) was introduced to achieve a full transmission rate for the four antennas system. In this paper, a decoding method for the QO-STBC is proposed to improve the bit-error-rate (BER) and to solve a rank-deficient problem. The proposed algorithm is based on the minimum mean-square-error (MMSE) technique. To overcome the implementation problem from the MMSE, an estimation method of the noise variance is developed in this paper. The proposed algorithm is implemented without matrix inversion, therefore, the proposed algorithm achieves a better BER than the conventional algorithms, as it has a low computational complexity. The simulation results show the low BER of the proposed algorithm in a Rayleigh fading channel.

Minimum Mean Square Error Algorithm for Improving Spectral Efficiency by Reducing Power Consumption of Beamforming in 5G Networks

“…A Minimum mean square error (MMSE) estimator can be described as "an estimation technique employed in statistics and signal processing that reduces the Mean square error (MSE), a popular indicator of estimator quality, of the fitted values of a dependent variable" [15][16][17][18]. The MMSE estimator`s shape is typically restricted to fall within a particular class of functions since computing the posterior mean is laborious [19].…”

Performance Analysis of Multiple Input Multiple Output (MIMO) Multi-Carrier Code-Division Multiple Access (MC-CDMA) Combined with Quasi-Orthogonal Space Time Block Coding (QO-STBC) in Rayleigh Fading Channel

“…The detection matrix used to decode the received signal is 𝐷 4 , 𝐻 𝜐 is the hermitian of 𝐻, and 𝑐 𝑛 is the channel's noise. The detection matrix for QO-STBC in this study can be shown below [18]:…”