A fixed point DSP implementation of a novel MIMO P2P radio link

In this paper we present the performance of DSP implementation for VBLAST receiver design used in our previously proposed enhancement of a P2P radio system. The system proposed uses a cochannel dual spatial dual polarisation mode allowing the transmission of 622 Mbps STM4 signals on four subchannels. Previously we have presented results using a LMS interference canceller at the receiver which, although it successfully cancelled the major interference effects, it did not fully utilise the possible diversity gains offered by this novel system configuration, or included the effects of fading in the channel. In this paper we present results from DSP implementations of both the existing system and a new receiver structure which employs both a MRC and ZF-VBLAST. The results show that a fixed point arithmetic implementation of the ZF-VBLAST receiver is able to give a 10 dB improvement in system performance for an increase in complexity of 1.2 times that of the floating point arithmetic LMS receiver.