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, bi-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 of a (16QAM/TDMA system) confirms that the proposed scheme improves frequency-selective fading compensation performance by 6 dB or more while using only 27% of the computation of conventional single branch DFE receivers. >

[1]  Hideki Imai,et al.  Design of a directional diversity receiver using an adaptive array antenna , 1991 .

[2]  M. Kuramoto,et al.  Overall system performance in a digital cellular system based on Japanese standard , 1993, IEEE 43rd Vehicular Technology Conference.

[3]  Asrar U. H. Sheikh,et al.  Adaptive equalization and diversity combining for mobile radio using interpolated channel estimates , 1991 .

[4]  Dominique Godard,et al.  Channel equalization using a Kalman filter for fast data transmission , 1974 .

[5]  H. Takai.  In-room transmission BER performance of anti-multipath modulation PSK-VP , 1993 .

[6]  Saeed S. Ghassemzadeh,et al.  Broadband-CDMA overlay , 1995, Int. J. Wirel. Inf. Networks.

[7]  Hiroshi Suzuki,et al.  Dual‐mode equalization for digital mobile radio , 1991 .

[8]  Seiichi Sampei,et al.  Performance of a decision feedback equalizer under frequency-selective fading in land mobile communications , 1990 .

[9]  Yasutaka Ogawa,et al.  An LMS Adaptive Array for Multipath Fading Reduction , 1987, IEEE Transactions on Aerospace and Electronic Systems.

[10]  W. C. Y. Lee,et al.  Overview of cellular CDMA , 1991 .

[11]  S. Sampei,et al.  Performance of multi-level QAM with post-detection maximal ratio combining space diversity for digital land-mobile radio communications , 1993 .

[12]  Hideichi Sasaoka,et al.  An implementation of a CMA adaptive array for high speed GMSK transmission in mobile communications , 1993 .

[13]  J. G. Proakis.  Adaptive equalization for TDMA digital mobile radio , 1991 .

[14]  Seiichi Sampei.  Development of Japanese Adaptive Equalizing Technology toward High Bit Rate Data Transmission in Land Mobile Communications , 1991 .