An Autonomous Resource Block Assignment Scheme for OFDMA-Based Relay-Assisted Cellular Networks

Abstract

Abstract-Terminal relaying offers an effective means for improving the performance of OFDMA-based wireless networks. However, with the increase in the number of relaying terminals (RTs), their coordination becomes a cumbersome task. To address this drawback, in this paper an autonomous scheme is proposed whereby the RTs assign resource blocks (RBs) to incoming wireless terminals (WTs) in a way that minimizes the number of hit occurrences at which the same RB is assigned to multiple WTs. The proposed scheme uses cyclic group generators to determine the sequence of RBs to be assigned by each RT. This scheme is particularly beneficial in terminal relaying systems in which the distribution of the WTs is nonuniform and the channel quality indicators are not available. Simulation results show that the proposed scheme performs significantly better than currently available autonomous assignment schemes.

An efficient greedy-based autonomous resource block assignment scheme for 5G cellular networks with self-organizing relaying terminals

“…To maintain autonomy, RB assignments can be performed randomly [4] or according to prescribed assignment sequences [5] with entries corresponding to available RBs. In either approach, no coordination with the BS or other RTs is required.…”

“…sequences. A more practical approach is the one in which the exhaustive search is restricted to cyclically-generated sequences [5], that is, sequences generated from a single element in the sequence.…”

“…These schemes offer a significant reduction in the overhead necessary to acquire the CQIs, but the lack of coherence in their structure results in, otherwise avoidable, RB allocation conflicts. This drawback is alleviated by the scheme proposed in [5] wherein the RB assignment sequences are endowed with a multiplicative cyclic group (MCG) structure. In [5], this structure was used to obtain cyclically-generated RB assignment sequences and an exhaustive search was performed to select the sequences that minimize the number of RB allocation conflicts between RTs.…”

“…This drawback is alleviated by the scheme proposed in [5] wherein the RB assignment sequences are endowed with a multiplicative cyclic group (MCG) structure. In [5], this structure was used to obtain cyclically-generated RB assignment sequences and an exhaustive search was performed to select the sequences that minimize the number of RB allocation conflicts between RTs. Despite its advantages, when the number of RTs increases, the cost of exhaustive search over cyclically-generated sequences becomes impractical.…”

“…This implies that it suffices for the greedy algorithm to be run once offline, independently of the number of RTs to be used in the system. This is in contrast with the sequences designed with exhaustive search [5], which is re-run each time the number of RTs in the network changes. To summarize, the proposed greedy algorithm possesses the following features:…”