A 32 Mbit/s mobile radio link

Quadrature amplitude modulation (QAM) for digital data transmission at 32 Mbits/s over mobile radio channels is considered. At this transmission rate intersymbol interference (ISI) will generally occur, causing problems in accurately recovering the received signal. The authors consider a novel QAM equalizer which gives the wideband system superior performance to the narrowband system by virtue of the inherent diversity in multipath transmission. The authors also consider a novel clock recovery scheme capable of working well with QAM signals corrupted by ISI which overcomes some of the problems associated with previous QAM clock recovery systems