Prototype implementation of adaptive beamforming-MIMO OFDMA system based on IEEE 802.16e WMAN standard and its experimental results

Abstract

This paper details the downlink performance analysis of a MIMO (Multi-Input Multi-Output) system that combines adaptive beamforming (ABF) and spatial multiplexing (SM) procedures. The combination of MIMO signal processing with ABF is applied to WiBro (Wireless Broadband), the South Korean orthogonal frequency division multiple access (OFDMA) system that follows the IEEE 802.16e standard. Performance analysis is based on the results of experiments and simulations obtained from a prototype system implementation and fixed-point simulator. Both the prototype experiments and simulations demonstrate that the ABF-MIMO OFDMA system improves the required signal to noise ratio (SNR) over the conventional MIMO OFDMA system by 3 dB (QPSK)/2.5 dB (16-QAM) for the frame error rate of 1% in the WiBro signal environments. From the implementation of the prototype system and its experimental results, we verify the feasibility of the ABF-MIMO technology for realizing a practical WiBro base station.