The Design And Implementation For TD-SCDMA Receiver Based On The General Purpose Processor

For TD-SCDMA system, the Joint-Detection algorithm is the key technology as part of the receiver. It can eliminate multiple access interference, multipath interference and near-far effect in the result of the improvement of system performance as well as increase of the cell coverage. On the other hand, the Intel CPU as the representative of a series of general-purpose processor (GPP) has got a very wide range of applications in the software area. For the real-time signal processing applications, compared to the conventional digital signal processor (DSP) and other dedicated processor, the general-purpose processor also has great potential for development. So at this stage, regardless of theory or practice, the design and development for TD-SCDMA receiver based on the general purpose processor has important practical significance.This paper’s subject is from school-enterprise cooperation projects between Beijing University of Posts and Telecommunications and China Mobile Research Institute. This paper is divided into two parts. One is the research for Joint-Detection algorithm theory in TD-SCDMA receiver. The other is the design and development for the Joint-Detection algorithm based on general-purpose processors.First, according to overall model of TD-SCDMA baseband uplink transmission system, we analyze and clarify the basic principles for Joint-Detection algorithm. Meanwhile, for the shortcomings of high complexity, we introduce the advanced algorithm which can effectively solve the ZF-BLE equations through fast inversion of matrix—approximate Cholesky-decomposition algorithm.Apart from theoretical research, this paper completed module design and code optimization for the approximate Cholesky-decomposition algorithm. Also this paper put forward the solution about how to do the software efficiency optimization when we develop real-time signal processing on the general-purpose processors platform. Methods of how to take advantage of the instruction pipelining, parallel processing technology, SIMD instruction set and other enhanced instruction set are explained in detail. Besides that, combined with the personal experiences accumulated in the process of debugging and optimization, the author summarized the methods such as data structure optimization, program structure optimization which have some versatility.The research results will greatly reduce the system overhead, lower the cost for base station. Also it can have broad application prospects and business value in the practical receiver in TD-SCDMA system.