The Design Of WiMAX Adaptive Modem Based On DSP

According to the defects of the WiMAX modem at present, such as low real-time property, complex structure and high price, the existing bit and power allocation algorithm is improved, and hardware and software design for the WiMAX adaptive modulation and demodulation scheme based on this algorithm are presented in this paper. The main contents of this paper are as follows:(1) Based on the analysis of current development of WiMAX modem and the defects of this modem, the adaptive algorithm of the existing WiMAX modem is improved and a kind of reliable WiMAX modem with high real-time property is designed.(2)Based on the simulation analysis of the existing WiMAX adaptive bit and power allocation algorithm, a new algorithm-floating threshold algorithm is suggested as an improvement of the existing fixed threshold algorithm. Through the simulation by matlab, the simplicity and high real-time property of the improved algorithm is proved, and the stability of channel utilization and bit error rate of the system can be greatly improved.(3)A hardware and software scheme is designed for the WiMAX adaptive modulation and demodulation. A high-speed DSP chip TMS320C6000 is chosen as the main chip to achieve the modulation and demodulation functions of the system. Meanwhile, bit and power allocation is achieved adaptively by the floating threshold algorithm, and the modem's real-time property and stability are improved.(4)The test for the WiMAX adaptive modem is given to verify its accuracy and stability. The result shows that this modem can operate reliably and stably.