Experiments on Real-Time 1-Gbps Packet Transmission Using QRM-MLD with ASESS in MIMO-OFDM Broadband Packet Radio Access

Abstract- This paper presents experimental results on real-time packet transmission of greater than 1 Gbps using 4-by-4 multiple-input mul-tiple-output multiplexing (MIMO) employing Maximum Likelihood Detection (MLD) with a decreased level of computational complexity in Orthogonal Frequency Division Multiplexing (OFDM) radio access. We apply our original algorithm called adaptive selection of surviving sym-bol replica candidates based on the maximum reliability (ASESS) in MLD employing QR decomposition and the M-algorithm(QRM-MLD) to reduce the extremely high level of computational complexity in the conventional MLD. The experimental results using multipath fading simulators are in good agreement with the computer simulation re-sults, confirming the effectiveness of our original signal detection algo-rithm, channel estimation filter, and likelihood function generation for successive soft-decision Turbo decoding based on real-time hardware implementation. We further show that the extremely high-speed real-time packet transmission of greater than 1 Gbps in a 100-MHz channel bandwidth (i.e., 10 bits/second/Hz) is achieved at the average received signal energy per bit-to-background noise power spectrum density ratio (Eb/N0) per receiver antenna of approximately 12 dB using 16QAM modu-lation and Turbo coding with the coding rate of 8/9 in 4-by-4 OFDM multiplexing. I