Showing papers by "Yanxiang Jiang published in 2012"

Method for estimating pilot frequency and communication channel of space division multiple access (SDMA) multi-antenna transmission down link

Abstract: The invention discloses a method for estimating a pilot frequency and a communication channel of a space division multiple access (SDMA) multi-antenna transmission down link, which provides possibility of saving orthogonal pilot frequency resources. In terms of the method, the pilot frequency signals in a transmitting antenna domain of different users can occupy the same time-frequency resource, thereby being capable of greatly reducing the pilot frequency cost for system resources. The method comprises: on account of the multi-antenna transmission down link which adopts precoding to carry out space division multiple access and at the transmitting terminal of a base station, firstly, determining the number of the orthogonal pilot frequency resources occupied by each user in a precoding domain as the number or the occupied space dimension of data streams which can be transmitted, and further carrying out precoding capable of implementing space division multiple access which is also carried out on the data signals on the orthogonal pilot frequency of the precoding domain so as to obtain the pilot frequency signals in the transmitting antenna domain of the users; and carrying out orthogonality on the pilot frequency in the precoding domain of each user in a frequency domain or a code domain, wherein the pilot frequencies in the precoding domain of different users can be differentor same; and the pilot frequency signals in the transmitting antenna domain of different users can occupy the same time-frequency resource.

A simplified equalization method for asynchronous cooperative relay systems

Abstract: In this paper, asynchronous cooperative relay systems based on distributed linear convolutional space-time codes are investigated. By utilizing the banded Toeplitz property of the equivalent channel matrix, a block minimum mean square error (MMSE) equalization method employing the Trench algorithm to solve the Toeplitz linear equations is proposed, which avoids the high order matrix inversion operation in the traditional MMSE equalization method. The computation of the equalization operation is further simplified greatly by converting the high order banded Toeplitz linear equations to the low order ones. Simulation results show that satisfactory system performance can be achieved by employing non-minimum-order non-trace-orthogonal generator polynomials.