Title :
A virtual channel detector for iterative receiver in overloaded MIMO OFDM systems
Author :
Denno, Satoshi ; Taya, Akihito ; Morikura, Masahiro
Author_Institution :
Grad. Sch. of Natural Sci. & Technol., Okayama Univ., Okayama, Japan
Abstract :
Iterative MIMO receivers with virtual channel are known to outperform linear detectors in overloaded multiple-input multiple-output systems with orthogonal-frequency division multiplex (MIMO-OFDM). This paper proposes a novel virtual channel detector that enables iterative MIMO receivers to achieve superior performance to the conventional receivers. Moreover, this paper proposes a novel signal estimation technique named as “extended maximum a posteriori probability (MAP) estimation” to select more reliable virtual channel. The proposed technique estimates the virtual channel with not only the a priori information on the virtual channels but also that on the real signals. The performance of the proposed detector with the extended MAP estimation is verified in a 6 × 2 MIMO OFDM system where the Turbo code is applied. The receiver with the proposed detector achieves much better performance than the conventional receivers. Actually, the proposed detector enables the MIMO receiver to achieve a gain of 3.0 dB at the BER of 10-5, compared with conventional receivers with virtual channels, e.g., the soft input soft output (SISO) MAP detector with the same Turbo decoder. It is confirmed that the proposed receiver has by about one-fifth less complexity than the receiver with the SISO MAP MIMO detector.
Keywords :
MIMO communication; OFDM modulation; channel coding; channel estimation; iterative methods; maximum likelihood estimation; probability; radio receivers; signal detection; turbo codes; MAP estimation; SISO MAP MIMO detector; Turbo code; Turbo decoder; extended maximum a posteriori probability estimation; gain 3.0 dB; iterative MIMO receiver; linear detectors; orthogonal-frequency division multiplex; overloaded MIMO OFDM systems; overloaded multiple-input multiple-output systems; signal estimation technique; soft input soft output MAP detector; virtual channel detector; virtual channel estimation; Decoding; Detectors; Estimation; Iterative decoding; MIMO; Receivers; Vectors;
Conference_Titel :
Signal Processing and Communication Systems (ICSPCS), 2014 8th International Conference on
Conference_Location :
Gold Coast, QLD
DOI :
10.1109/ICSPCS.2014.7021069