Cross-Layer Design Using Superposition Coding Scheme for Multiuser OFDM Systems

Transmission completion time minimization in digital network coding assisted two-way relay OFDM networks

“…There have been continuing interest in the resource allocation problem for network coding aware OFDM networks in the literature (see e.g., [19][20][21][22][23]). In [19] and [20], the authors studied the joint optimization problem of subcarrier-pairing-based relay selection, relay power allocation, and subcarrier assignment, where however, the network coding was not taken into account.…”

“…In [21], the power allocation under total power constraint to maximize the MSR for ANC-based two-way relay networks and, in [22], the subcarrier-paring, relay selection, and power allocation were jointly optimized to maximum the MSR for twoway relay networks. In [23], energy-efficient resource allocation was studied for OFDMA-based two-way relay channel, where the physical-layer network coding was considered.…”

“…Firstly, in most of the previous works (see, e.g., [22,23,25]), it was assumed that the sources always have a constant, stable, and equal mount of data to exchange. Therefore, all the data received at the relay node can be network coded and then forwarded.…”

“…As such, we investigate the resource allocation problem for both source phase and relay phase, for accomplishing a whole round of two-way relay transmission. Some of the aforementioned previous works (see, e.g., [23]) considered only the relay stage of the two-way relay transmission. Thirdly, in many other works, to achieve more coding opportunities, complex queue management was involved [28], which may lead to higher complexity of system implementation and larger transmission delay for flows.…”