Gaussian Diamond Primitive Relay with Oblivious Processing

Abstract

We examine the frequency-selective Gaussian primitive diamond relay channel, where the signal received at both relays is described by identical frequency-selective Gaussian channels, and where the relays are connected to the destination via noiseless fronthaul links of a given capacity. The frequency response of the filters are available to all system components. We characterize analytically the Gaussian input frequency power distribution that maximizes the optimal information rate of the oblivious (code independent) relay operation achieved by joint decompression-decoding (or optimized Wyner-Ziv) procedure.

Information Bottleneck for a Rayleigh Fading MIMO Channel with an Oblivious Relay

“…The IB problem for this kind of communication scenario has been studied in [12,[20][21][22][23][24][25][26]. In [20], the IB method was applied to reduce the fronthaul data rate of a C-RAN network.…”

“…References [21,22], respectively, considered Gaussian scalar and vector channels with IB constraint and investigated the optimal tradeoff between the compression rate and the relevant information. In [23], the bottleneck rate of a frequency-selective scalar Gaussian primitive diamond relay channel was examined. In [24,25], the rate-distortion region of a vector Gaussian system with multiple relays was characterized under the logarithmic loss distortion measure.…”

“…Reference [12] further extended the work in [25] to a C-RAN network with multiple transmitters and multiple relays and studied the capacity region of this network. However, all of References [12,[20][21][22][23][24][25] considered block fading channels and assumed that the perfect channel state information (CSI) was known at both the relay and the destination nodes. In [26], the IB problem of a scalar Rayleigh fading channel was studied.…”

The Filtered Gaussian Primitive Diamond Channel

“…1, to the destination accounting for limited available communication rate at the fronthaul links, connecting the RRHs to the CU. This problem was examined in [1] where we used the oblivious CF with distributed compression. Here we expand the system model by allowing the relays to do time-sharing between CF and DF.…”

“…Here we expand the system model by allowing the relays to do time-sharing between CF and DF. As in [1] we extend the examination to account for frequency selective channels, assuming equal characteristics, from the mobile device to the RRHs. The optimal solution divides time and frequency assignments between CF and DF.…”