We investigate cooperative wireless relay networks in which the nodes can help each other
in data transmission. We study different coding strategies in the single-source single-
destination network with many relay nodes. Given the myriad of ways in which nodes can
cooperate, there is a natural routing problem, i.e., determining an ordered set of nodes to
relay the data from the source to the destination. We find that for a given route, the
decode-and-forward strategy, which is an information theoretic cooperative coding
strategy, achieves rates significantly higher than that achievable by the usual multi-hop
coding strategy, which is a point-to-point non-cooperative coding strategy. We construct
an algorithm to find an optimal route (in terms of rate maximizing) for the decode-and-
forward strategy. Since the algorithm runs in factorial time in the worst case, we propose a
heuristic algorithm that runs in polynomial time. The heuristic algorithm outputs an optimal
route when the nodes transmit independent codewords. We implement these coding
strategies using practical low density parity check codes to compare the performance of the
strategies on different routes.