COMPLEXITY REDUCTION AND PERFORMANCE IMPROVEMENT OF A DECISION-FEEDBACK EQUALIZER FOR 16QAM IN LAND MOBILE COMMUNICATIONS

This paper proposes a complexity-reduced decision feedback equalizer (DFE) for 16-ary quadrature amplitude modulation (16QAM) using tap gain interpolation, hi-directional equalizing (BDE) and space diversity combining (SDC) to achieve high spectral efficiency and high quality data transmission over frequency-selective fading channels in land mobile communications. To reduce the amount of computation required for BDE and SDC, we propose a tap gain interpolation scheme and pre-decision schemes for both processes. Computer simulation confirms that the proposed scheme improves frequency-selective fading compensation performance by 6 dB or more white using only 27% of the computation of conventional single branch DFE receivers.