实现π/4-DQPSK调制的一种快速算法

A Fastπ/4-DQPSK Modulation Arithmetic

针对π/4-DQPSK调制数字化实现的运算量大、高速调制难的问题,提出了一种适合于数字调制的快速算法。该算法基于TMS320C54xDSP处理器,应用查找表的方法完成π/4-DQPSK的差分编码与符号映射,应用波形存储的方法完成I、Q通道的成形滤波,用选通直读的方法实现载波调制,整个调制过程中不需要乘法运算,节约了调制时间。仿真结果验证了该方法的有效性。

Aiming at that the π/4-DQPSK digital modulation need large amount of operation and fast modulation is achieved difficultly. A fast arithmetic based on digital modulation is present in this paper. The arithmetic bases on TMS320C54x DSP processor. Difference coding and signal mapping is completed by look-up tables, Shaping FIR filtering for channel I and Q is completed by wave storage and Carrier modulation is completed by strobe and reading directly. There are no multiplications in whole modulation. The speed of modulation is faster. Simulating result proves the effectivity of the arithmetic.