An implementation of a CMA adaptive array for high speed GMSK transmission in mobile communications
Takeo Ohgane, T.M. Shimura, N. Matsuzawa, Hideichi Sasaoka · IEEE Transactions on Vehicular Technology · 1993
The hardware implementation of an adaptive array as a technique for compensating multipath fading in mobile communications is described. The number of the antenna elements is four. The target communication system is modulated by 256 kbps Gaussian-filtered minimum shift keying (MSK) and has a time-division multiplexing (TDM) architecture with 24 time slots. Based on the digital beamforming concept, all of the signals and the array weights are digital-signal processed. The constant modulus algorithm (CMA) is employed for weight optimizing. In an additive white Gaussian noise channel, this system has 5.6-dB gain in an energy-per-bit-to-noise-density ratio at a bit error rate (BER) of 1.0*10/sup -3/, compared with a single antenna system. The result of the basic field test shows that the gain at a BER of 1.0*10/sup -3/ reaches 22.3 dB in a nonselective, slow Rayleigh fading channel given a 5 Hz maximum Doppler shift.>