Visual dsp++环境下QPSK调制程序

comsim

Visual dsp++环境下QPSK调制程序 Description : This function maps the input bits to the corresponding symbols in the look up table. Assumptions : 1. The bitstream is stored in a character array where the start of the bitstream is at the LSB of the first character 2. All the characters are full (i.e. the bitstream size is at least a multiple of 8) 3. Since two characters from the input bitstream are read at a time, the bitstream size should be a multiple of 16 (i.e. the no. of chars in the i/p array should be even) 4. The size of the I and Q arrays is 4 times that of the input array 5. The I and Q channel outputs corresponding to the input two bit symbols should be stored in the table in the following manner: I/P data I Q 00 table[0](LB) table[0](HB) 01 table[2](LB) table[2](HB) 10 table[1](LB) table[1](HB) 11 table[3](LB) table[3](HB) where LB - lower byte HB - Higher byte Note that the IQ components of symbol 01 are stored in table[2] and for 10 are in table[1]. This is so because, the bitstream is assumed to start from the LSB and continue till the MSB of the first character and then start again from the LSB of the next char and so on. Hence a '01' in the register is equivalent to a '10' in the actual bitstream. qpsk.rar (8 K) 下载次数:0 （转自通信仿真网，http://www.comsim.cn/read.php?tid=28）

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canito777

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