Signal sending method based on code book precoding in MIMO (Multiple Input Multiple Output) relay system

Abstract

The invention provides a signal sending method based on code book precoding in an MIMO (Multiple Input Multiple Output) relay system. The method comprises the steps of: constructing code books W1 and W2 which both comprise an optimal precoding matrix and a power allocation matrix respectively for a first jump channel and a second jump channel according to a minimized average quantization error criterion; selecting optimal code words from the code books W1 and W2 by a relay end and a terminal respectively according to the state information of the first jump channel and the second jump channel and feeding back index values of the optimal code words in corresponding code books respectively to a source end and the relay end; and acquiring corresponding optimal code words from corresponding code books by the source end and the relay end, encoding according to the optimal precoding matrix and the power allocation matrix which are contained in the optimal code and sending signals. The methodcan improve the property of the whole MIMO relay system and reduce the feedback delay of system feedback.

Description

technical field The present invention relates to a signal transmission method based on codebook precoding in a MIMO relay system, in particular to a codebook construction and distributed codeword suitable for a MIMO relay system that combines power allocation and precoding matrix Method of choosing. Background technique With the development of wireless communication, high data rate and high quality of service have become the basic goals of communication system design. Therefore, limited wireless spectrum resources force the next generation of wireless communication technology to greatly improve spectrum utilization. MIMO technology has been widely studied because it introduces multiple antennas at the transmitting end and receiving end, which can greatly improve the channel capacity and spectrum efficiency without increasing the system bandwidth and power. However, due to the constraints of mobile terminal quality, volume and power consumption requirements, the existing mul...

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Problems solved by technology

However, the noise introduced by the relay end due to the way of amplification and forwarding makes the Grassmannian codebook not the optimal codebook for the MIMO relay system; when there is no direct transmission path between the source end and the terminal, if the terminal uses the maximum To select codewords based on the capacity criterion, a matrix inversion process will be introduced into the system capacity formula, which will increase its complexity; moreover, in traditional codeword selection, the terminal must feed back the selected codebook index value to the source. and the relay end, which will introduce a large feedback delay in the two-hop MIMO relay system with no direct transmission link between the source end and the terminal; the existing distributed codeword selection criteria only consider the minimum eigenvalue of the two-hop channel, Therefore, the selected codeword cannot approach the optimal value; in addition, the traditional codebook design criterion only considers the quantization of the precoding matrix, and the average power allocation is used in the MIMO relay system, so the system performance cannot reach the optimum

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