Multilevel coding strategy for two-hop single-user networks

Abstract

In this paper, a two-hop network in which the information is transmitted from a source via a relay to a destination is considered. It is assumed that both channels are quasi-static fading and all nodes are equipped with a single antenna. The knowledge of the channel for each transmission hop is only available at the corresponding receiver. The relay is assumed to be simple, i.e., not capable of data buffering over multiple coding blocks or rescheduling tasks. Considering a continuum of multilevel codes at both of the source and the relay, in conjunction with decode and forward strategy, we present a scheme to optimally allocate the available source and relay powers to different levels of their multilevel codes. Assuming Rayleigh fading, the performance of this scheme is also evaluated and compared with the previously known strategies.

The achievable average rate- outage probability trade off curve in two-hop block fading channels

“…R avg,o is the average rate at the destination when g 1 s th1 and g 2 s th2 . Considering the conditional pdf of the source-relay and the relay-destination links are denoted, respectively, by f g1 (x|x s th1 ) and f g2 (y|y s th2 ), following the same approach in [4], the conditional average rate at the destination can be formulated as 1 ,…”

“…From now on, for ease of notation, the conditional pdf of f g1 (x|x s th1 ) and f g2 (y|y s th2 ) are represented by f g1 (x|s th1 ) and f g2 (y|s th2 ), respectively. Since the optimization problem is not in the isoperimetric form, we rewrite it as two-step optimization problem and solve by Euler-Lagrange equations [4].…”

“…When there is no direct link between transmission ends, the destination can merely receive the relay's transmitted signal which is a degraded version of the relay's. In this case, it is argued that the DF strategy is optimal [4]. Accordingly, using the broadcast strategy, the achievable average rate of two-hop channel in the presence of DF relay is numerically computed in [4].…”

“…In this case, it is argued that the DF strategy is optimal [4]. Accordingly, using the broadcast strategy, the achievable average rate of two-hop channel in the presence of DF relay is numerically computed in [4].…”

Infinite-layer codes for single-user slowly fading MIMO channels

“…Reference [5] combine the multi-layer scheme with the Hybrid Automatic Retransmission Request (HARQ) and show that this approach results in high throughput and low latency. The twohop extension of [1] is also discussed in [6] and [7].…”