Title :
Comparison of Two Suboptimal SISO Iterative Demodulators: LMMSE Estimation and Vector Gaussian Approximation
Author :
Zhang, Guomei ; Zhu, Shihua ; Wang, Shaopeng
Author_Institution :
Sch. of Electron. & Inf. Eng., Xi´´an Jiaotong Univ., Xi´´an
Abstract :
The linear minimum mean-square error (LMMSE) estimator and the vector Gaussian approximation (GA) demodulator are two popular low-complexity suboptimal SISO demodulating methods for soft interference cancellation based iterative detection. In this paper, the equivalence of the two demodulation methods is established. In addition, the complexities of the two demodulators with arbitrary mapping constellations are reduced by reducing the number of matrix inverse operations in the preceding block processing. The comparison of the computational complexities demonstrates that the LMMSE demodulator is simpler than the one using the vector GA algorithm. Since the performances of the two methods are equivalent, the less complex LMMSE method has the advantage over the vector GA one for the SISO iterative detection.
Keywords :
Gaussian processes; computational complexity; demodulation; genetic algorithms; least mean squares methods; matrix algebra; LMMSE estimation; block processing; computational complexities; genetic algorithms; iterative detection; linear minimum mean-square error; matrix inverse operations; suboptimal SISO iterative demodulators; vector Gaussian approximation demodulator; Computational complexity; Demodulation; Detectors; Gaussian approximation; Interference cancellation; Iterative decoding; Iterative methods; OFDM; Telephony; Vectors;
Conference_Titel :
Circuits and Systems for Communications, 2008. ICCSC 2008. 4th IEEE International Conference on
Conference_Location :
Shanghai
Print_ISBN :
978-1-4244-1707-0
Electronic_ISBN :
978-1-4244-1708-7
DOI :
10.1109/ICCSC.2008.59
