Research And Implementation Of Joint Detection Algorithm In Hspa+System

TD-SCDMA HSPA+technology is an important evolution scheme of TD-SCDMA system and has a tremendous increase of efficiency by introducing Multi-Input Multi-Output (MIMO), high order modulation and enhanced L2layer. Joint Detection is a key technology and algorithm in TD-SCDMA HSPA+physical layer, it leads to a great enhance in system performance and larger the cover area of a cell due to distinguish treatment of noise and inference can relieve MAI and multi path inference. Additionally, Software Defined Radio technology (SDR) can realize high speed digital signal processing algorithm in flexible customized system. SDR has attracted more and more attractions, and many wireless signal processing algorithm and standards are verified and implemented in this system. This paper simulate the performance of HSPA+system physical layer both in float-point and fixed-point, also implement it in a real-time operation system of a SDR system. We first introduce the joint detection algorithm in theory aspect, make a discussion of high computing complexity of current joint detection algorithm, then research the principle and implement method of the algorithm, finally verify the algorithm’s performance by simulation. This paper discuss about the matrix inversion operation and its implement in down link physical in SDR system which based on high speed Digital Signal Processor (DSP) can process base band signal. We first transfer some float point variable to fixed variable in the algorithm, then make a trade-off between the time consumption and loss of performance, finally, further optimization is made to satisfy the precision and delay in link. Last, we summarize methods to optimize the program in DSP to make further optimization more easily.