Decision feedback equalisation of coded I-Q QPSK in mobile radio environments
The bit error rate (BER) performance of equalised I-Q quadrature phase-shift keying (QPSK) is evaluated for wideband cellular systems. Decision feedback equalisation with the square-root Kalman updating algorithm is employed for I-Q coded systems. A gain of about 6 dB is achieved in favour of the I-Q scheme compared with the conventional Gray-mapped QPSK at a BER of 10–3.