Power Allocation and Hybrid Relaying Strategies for F/TDMA Ad Hoc Networks

Abstract

Abstract-In this paper, we study the power allocation problem at the relay nodes for two-hop F/TDMA networks with multiple sources and destinations. Each relay node is assumed to be capable of assisting multiple source nodes and of selecting one of regenerative decode-and-forward (RDF), nonregenerative decode-and-forward (NDF), amplify-and-forward (AF) and compress-and-forward (CF) relaying strategies to assist each source node. Considering the sum capacity as the performance metric, we solve the problem of optimally allocating the total power of each relay node between the transmissions it is assisting. We first obtain the optimum power allocation policies for the relay nodes when the relaying strategies of all source nodes are given. Next, to obtain higher sum capacities, we investigate the optimum power allocation problem jointly with relaying strategy selection. We observe that optimum power allocation with the appropriate hybrid relaying strategies provides higher sum capacity than pure RDF, NDF, AF or CF relaying strategies.

Cooperative transmission based on decode-and-forward relaying with partial repetition coding

“…3 shows the optimum choice of δ (δ opt ) for decode-andforward with parallel coding and with partial repetition when all nodes lie on a straight line, i.e., d sd = 1, d rd = 1 − d sr , and P s = P r = P . The optimal value of δ is found using an exhaustive grid search over the feasible set of solutions to (21) and (22). It can be seen that the optimal δ increases as d sr increases for a given spectral efficiency.…”

“…Decode-and-forward (DF) [4], [6] and amplify-and-forward (AF) [4], [5] are two well-studied relaying protocols in the literature. Some other strategies such as hybrid relaying have been studied as well [22], [23]. One advantage of DF is the possibility to vary the communication rate on the S − R and R − D links, which is not possible using the AF protocol in a straightforward fashion [7].…”

Joint Subcarrier Matching and Power Allocation for OFDM Multihop System

“…The AF cooperative relay scheme was developed and analyzed in (Shastry & Adve, 2005), where a significant gain in the network lifetime due to node cooperation was shown. Power allocation is studied and compared for AF and DF relaying strategies for relay networks, which improves the channel capacity (Serbetli & Yener, 2006). However, DF means that the signal is decoded at the relay and recoded for retransmission.…”

Iterative Power Allocation Algorithms for Amplify/Estimate/Compress-and-Forward Multi-Band Relay Channels

“…The optimum source and relay transmit power and time-slot allocation has been investigated for the three node half-duplex relay channel in reference [4]. The optimum relay transmit power allocation was investigated in [17] for various relaying transmission schemes for a relay assisted F/TDMA network with multiple source-destination pairs where all channels of all sources nodes and relay nodes are orthogonal. The bandwidth and power allocation for the relay networks where a single source and destination pair with multiple relay nodes employing amplify-and-forward and decode-and-forward schemes was investigated in [16].…”