A Proposal of New Hybrid ARQ Scheme Suitable for Multi-Hop Transmissions Using LDPC Codes

摘要

Multi-hop ad-hoc networks are promising candidates for next generation wireless communications. When using HARQ for multi-hop transmissions, each relay node has to decode received messages and request retransmission to its previous node when it detects errors. Thus, every relay node is required to spend extra power and time because of retransmissions and decodes for collaboration of transmission by the source node. We propose a new HARQ scheme that can reduce the load of the relay nodes but maintain high throughput. In this scheme, every relay node neither decodes the received messages nor requests retransmission to reduce the load. Only the destination node decodes messages by using LDPC codes. RC-LDPC codes, which are suitable for Type-II HARQ, are utilized in the proposed ARQ scheme. Throughput performance of the proposed scheme is evaluated to show its effectiveness.