Recently, it has been proven that retransmission based on networkcoding(NC) can greatly improve the performance of wireless networks with broadcast erasure channels. However, networkcoding also introduces additional...
详细信息
Recently, it has been proven that retransmission based on networkcoding(NC) can greatly improve the performance of wireless networks with broadcast erasure channels. However, networkcoding also introduces additional delay at the both sending and receiving sides, resulting in the decline of the Quality of user Experience(QoE). In this paper, we consider the users' waiting time and the decoding delay as the performance metrics and then propose Mix Code, a novel NC-based loss recovery method, to improve the delay performance in heterogeneous wireless networks. Mix Code incorporates opportunistic network coding(ONC) with Random Linear networkcoding(RLNC), where a NC packet can be decoded by simply XORing operation at some destinations, but by Gaussian elimination at other destinations. Simulation results show that our proposed algorithm can efficiently reduce both the waiting time and the decoding delay in comparison with the existing NC-based schemes.
Next-generation cellular networks are expected to be assisted by femtocaches (FCs), which collectively store the most popular files for the clients. Given any arbitrary non-fragmented placement of such files, a strict...
详细信息
ISBN:
(纸本)9781479959532
Next-generation cellular networks are expected to be assisted by femtocaches (FCs), which collectively store the most popular files for the clients. Given any arbitrary non-fragmented placement of such files, a strict no-latency constraint, and clients' prior knowledge, new file download requests could be efficiently handled by both the FCs and the macrocell base station (MBS) using opportunistic network coding (ONC). In this paper, we aim to find the best allocation of coded file downloads to the FCs so as to minimize the MBS involvement in this download process. We first formulate this optimization problem over an ONC graph, and show that it is NP-hard. We then propose a greedy approach that maximizes the number of files downloaded by the FCs, with the goal to reduce the download share of the MBS. This allocation is performed using a dual conflict ONC graph to avoid conflicts among the FC downloads. Simulations show that our proposed scheme almost achieves the optimal performance and significantly saves on the MBS bandwidth.
In this paper, a feedback-based opportunisticnetwork-coded cooperative scheme is proposed to be combined with cooperative communication in wireless uplink multi-relay networks. Different from previous network-coded s...
详细信息
ISBN:
(纸本)9781479903061
In this paper, a feedback-based opportunisticnetwork-coded cooperative scheme is proposed to be combined with cooperative communication in wireless uplink multi-relay networks. Different from previous network-coded schemes that conduct networkcoding all the time, we propose a scheme that conducts networkcoding and direct transmission alternately according to the quality of the channels. The outage probability is analyzed theoretically and the approximate expression of outage probability is derived. Compared with the previous schemes, the proposed scheme achieves a performance gain in terms of outage probability. The validity of the proposed scheme is verified by theoretical analysis and simulation results.
暂无评论