Performance of Uncoded and LDPC Coded MSK and GMSK in Nakagami Fading

Low density parity check (LDPC) codes are one of the best error correcting codes in today’s coding world and are known to approach the Shannon limit. As with all other channel coding schemes, LDPC codes add redundancy to the uncoded input data to make it more immune to channel impairments. In addition to coding, the best modulation techniques available today are MSK (Minimum Shift Keying) and GMSK (Gaussian Minimum Shift Keying). By using these modulation techniques in combination with LDPC codes, the paper compares the performance of coded MSK and coded GMSK with each other and with their uncoded counterparts over Nakagami fading channel for different values of m. The results show that a significant coding gain is obtained by using LDPC codes. It is also seen that although the error performance of LDPC coded MSK is slightly better than LDPC coded GMSK, the former is spectrally inefficient.