Multi-resource optimization algorithm for DF (Decode-and-Forward) multi-relay OFDM (Orthogonal Frequency Division Multiplexing) system making full use of time slot to transmit information

Abstract

The invention relates to the field of wireless communications, and discloses a transmission strategy that fully utilizes double time slots to transmit information, and a multi-resource joint optimization algorithm in a DF (Decode-and-Forward) cooperative multi-relay OFDM (Orthogonal Frequency Division Multiplexing) system under the transmission strategy. The multi-resource joint optimization method comprises the following steps: considering a time-division half-duplex relay, and sending information by a source node on each subcarrier in two time slots; and under a total power constraint condition, performing joint optimization on multi-relay selection and cooperative transmission, time slot freedom, transmission mode, subcarrier pairing and power allocation and other resources, so as to maximize the system transmission rate. The whole system structure is composed of one source node, one target node and K relay nodes, and a selective transmission bandwidth is divided into N subcarriers through an OFDM technology. Compared with the prior art, the optimization algorithm of the invention has a higher information transmission rate and spectral efficiency.

Description

technical field [0001] The invention belongs to the related field of wireless cooperative relay communication technology, and relates to a DF (Decode-and-Forward, decoding and forwarding) multi-relay OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing) aiming at maximizing system capacity A joint optimization method for various resources in the system (including time freedom, selection and cooperative communication of multiple relays, selection of transmission mode, how to pair subcarriers, and power allocation). Background technique [0002] In the traditional wireless communication cellular structure, in order to enhance the communication capacity and extend the signal coverage, a large number of base stations are required, which increases the cost of communication services. The use of low-complexity cooperative relay nodes in wireless communication can effectively expand the coverage of signals in the cell, enhance the reliability ...

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Problems solved by technology

[0004] For the DF multi-relay OFDM system, the existing domestic and foreign related literatures have jointly optimized one or two of resources such as power allocation, subcarrier pairing, and relay selection, such as: "Relay selection and power allocation in Cooperative cellular networks" only optimizes power allocation, and only selects one relay for each subcarrier to forward information, but does not analyze subcarrier pairing, transmission mode, multi-relay coordination, time freedom, etc.; "Sum Rate Maximized Resource Allocation in Multiple DFRelays Aided OFDM Transmission" and "WSR Maximized Resource Allocation in Multiple DF Relays Aided OFDMA Downlink Transmission" analyzed power allocation, multi-relay selection and coordination, but for subcarrier pairing, transmission mode, and time freedom "Asymptotically Optimal Resource Allocation in OFDM-Based Cognitive Networks with Multiple Relays" analyzed power allocation and subcarrier pairing. Each subcarrier pair only selects one relay to forward information, but for multiple relays Cooperative communication, transmission mode, and time degrees of freedom were not analyzed; the first inventor of the present invention conducted further research on the joint optimization of multiple resources in the document "Joint Resource Allocation with Subcarrier Pairing in Cooperative OFDM DF Multi-Relay Networks" , but did not analyze the time degree of freedom, dual-slot information transmission strategy, etc.

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