Analysis of a Cooperative Strategy for a Large Decentralized Wireless Network

Abstract

Abstract-This paper investigates the benefits of cooperation and proposes a relay activation strategy for a large wireless network with multiple transmitters. In this framework, some nodes cooperate with a nearby node that acts as a relay, using the decode-and-forward protocol, and others use direct transmission. The network is modeled as an independently marked Poisson point process and the source nodes may choose their relays from the set of inactive nodes. Although cooperation can potentially lead to significant improvements in the performance of a communication pair, relaying causes additional interference in the network, increasing the average noise that other nodes see.We investigate how source nodes should balance cooperation vs. interference to obtain reliable transmissions, and for this purpose we study and optimize a relay activation strategy with respect to the outage probability. Surprisingly, in the high reliability regime, the optimized strategy consists on the activation of all the relays or none at all, depending on network parameters. We provide a simple closed-form expression that indicates when the relays should be active, and we introduce closed form expressions that quantify the performance gains of this scheme with respect to a network that only uses direct transmission.Index Terms-Cooperative communication, interference, network management, outage probability, decode and forward, marked Poisson point processes.

Limited-Feedback Distributed Relay Selection for Random Spatial Wireless Networks

“…Based on the first hop location and channel knowledge, the work [11] considered the selection of the closest relay to the source in order to relay the messages to the destination. In [12], the optimum relay activation probability was analyzed when relays were selected based on their distances to the source node. In [13], a random relay selection policy choosing a relay in an area around the source-destination mid-point was proposed and its outage was compared with the nearest-neighbor relay selection.…”

“…τ ) 1 { s(X)≤T } N = n ] = nPr { s (U ≤ T )},where U is a generic random variable uniformly distributed over B (0, τ ). Using this observation, we can write µ (T, τ ) as µ (T, τ ) = λπτ 2 Pr { s (U ) ≤ T } (12). …”

Interference Modeling for Cellular Networks Under Beamforming Transmission

“…This work can be extended to model interference in more complicated propagation environments, including those with a probabilistically parametrized LOS and NLOS channel model, and to more heterogeneous network deployment such as those involving relaying nodes [13]- [15].…”

Location-Based Optimum Relay Selection in Random Spatial Networks

“…Without considering any time-scale separation between fading and relay location processes, they also studied the outage performance of both random and best relay selections from this QoS region. In [9], the optimum relay activation probability was analyzed for decodeand-forward (DF) relays selected based on their distances to the source node. In [10], the outage probability was analyzed with imperfect channel state information (CSI) when the relay having the best channel to the destination is selected to forward messages.…”