Capacity scaling of (long) non-regenerative MIMO multi-hop channels

Abstract

We consider coherent wireless MIMO multi-hop communication where n S non-cooperating source antennas communicate to n D fully cooperating destination antennas via L clusters of n R non-cooperating relay antennas each. Assuming i.i.d. zero-mean (slow) fading coefficients of finite variance, the sum-capacity of this channel is proven to scale linearly in min{n S , n D } in the limit Lrarrinfin, when the receive SNR is kept constant and n R isinOmega(min{n S , n D }). This capacity scaling is achieved by a quantization based forwarding strategy. Moreover, we show that Slepian & Wolf compression allows to reduce the growth rate of the transmit power per cluster that is necessary to sustain a constant receive SNR at the destination antennas from exponential to linear in L.