We consider spatially-coupled protograph-based LDPC codes for the three terminal erasure relay channel. It is observed that BP threshold value, the maximal erasure probability of the channel for which decoding error probability converges to zero, of spatially-coupled codes, in particular spatially-coupled MacKay-Neal code, is close to the theoretical limit for the relay channel. Empirical resul...

In a bi-directional relay channel, two nodes wish to exchange independent messages over a shared wireless half-duplex channel with the help of relays. Recent work has considered information theoretic limits of the bi-directional relay channel with a single relay. In this work we consider bi-directional relaying with multiple relays. We derive achievable rate regions and outer bounds for half-du...

The authors investigate the performance of amplify-and-forward relaying with two different pilotsymbol-assisted channel estimation methods. In the first estimation method, the cascaded channel consisting of source-to-relay and relay-to-destination links is estimated at the destination terminal. No channel estimator is required at the relay terminal. In the second estimation method, the estimati...

Combining-type relay systems can benefit from distributed array gain if the signals retransmitted from different relays are superimposed coherently at the destination. For this purpose, we propose a low-complexity hybrid framework in which the non-regenerative multiple-input-multiple-output relaying matrix at each relay is generated by cascading two substructures, akin to an equalizer for the b...

i−1 1) Fig. 1. Relay channel. The user, aided by the relay, sends the message M to the receiver. The relay channel is a channel in which there is one sender and one receiver with an intermediate node that acts as relay to help the communication. The channel model consists of four finite sets X , X 1 , Y, Y 1 , and a collection of conditional pmfs p(y, y 1 |x, x 1) on X × X 1 × Y × Y 1. The send...

In this paper, we investigate the capacity problem of Gaussian fading multiple access relay channel with orthogonal components from the senders to the relay receiver and from the senders and relay to the receiver. This model is motivated by the practical constraint that a node cannot send and receive at the same time or in the same frequency band. We derive a capacity region for the model where...

This paper considers the partial decode-and-forward (PDF) strategy for the Gaussian multiple-input multiple-output (MIMO) relay channel. Unlike for the decode-and-forward (DF) strategy or pointto-point (P2P) transmission, for which Gaussian channel inputs are known to be optimal, the input distribution that maximizes the achievable PDF rate for the Gaussian MIMO relay channel has remained unkno...

Cooperative communication is used as an effective measure against fading in wireless communication systems. In a classical one-way cooperative system, the relay needs as many orthogonal channels as the number of terminal it assists, yielding a poor spectral efficiency. Efficiency is improved in two-way relaying systems, where a relay simultaneously assists two terminals using only one timeslot....

In this two part paper we consider a wireless network in which a source terminal communicates with a destination and a relay terminal is occasionally present in close proximity to the source without source's knowledge, suggesting oblivious protocols. The source-relay channel is assumed to be a fixed gain AWGN due to the proximity while the source-destination and the relay-destination channels a...