Multi-user multi-relay downlink transmission method in multi-input multi-output cellular communication system

Abstract

The invention relates to a multi-user multi-relay downlink transmission method in a multi-input multi-output cellular communication system, which comprises the following main steps: (1) in a first time slot, a base station performs Tomlinson-Harashima precoding to transmit data to all relay and base station service users; (2) detection by the base station service users and amplification by the relays: in the first time slot, the base station service users receiving signals detect out original data information, and the relays directly amplify the received data; (3) in a second time slot, the base station and the relays perform interference alignment based precoding, the base station transmits a new symbol to a new base station service user, and the relays precode amplified and transmitted data and send the data to all relay service users; and (4) detection in the second time slot: the base station service users and all relay service users receiving the data in the second time slot detect out a sending signal. By using the method, the free degree of a space division channel is fully utilized, the frequency spectrum utilization rate is high, the system expense is low, and system timing is not sensitive.

Description

technical field [0001] The invention relates to a relay transmission method of a multiple-input multiple-output (MIMO) communication system, in particular to a downlink multi-user multiple-relay transmission method in a multiple-input multiple-output cellular communication system. Background technique [0002] Studies have shown that in a cellular communication system based on multiple input and multiple output, relay technology can effectively reduce the waste of power resources caused by path loss, improve the receiving signal-to-noise ratio of edge users, and expand the scope of communication coverage. The technology can make full use of the spatial freedom of the system and provide the system with higher data rate and spectral efficiency. Relay transmission schemes are divided into two types: decode-and-forward (DF) and amplify-and-forward (AF). Among them, AF relay is widely used due to its advantages of low complexity and fast processing speed. [0003] In an AF-based...

AI Technical Summary

Problems solved by technology

Among the existing technical schemes, some schemes adopt frequency division (FDD) or time division (TDD) methods to coordinate the transmission of different data on orthogonal time-frequency channels. These schemes do not make full use of the space division channels of the MIMO system characteristics, causing a certain loss of system resources

There are also some solutions that regard multiple relays as a virtual MIMO system, and use coordinated beamforming among different relays to eliminate interference between users. These solutions require the exchange of user channel information and data information between relays, increasing the It reduces the system overhead and is very sensitive to the timing of relay transmission, so it puts forward high requirements for the realization of the system

[0004] To sum up, the existing multi-relay technology still has certain defects in solving multi-user interference, making full use of space division channels, and system implementation complexity. How to design a suitable multi-relay system that can eliminate Interference between users, making full use of space-divided channel information, and a multi-relay transmission scheme suitable for real-world scenarios are of great significance

Images