A Linear Approximation of GMSK Modulation for GSM/EDGE Mobile Communications

Gaussian minimum shift keying (GMSK) modulation is one of the key technologies at the standard of GSM/EDGE mobile communications. The traditional algorithms are difficult to implement in VLSI design because of their complexity. This paper presents a new full digital scheme of linear approximation based on the partial response signaling and inter-symbol interference(ISI) properties. The theory for the full digital scheme is analyzed. And the modulator is realized on FPGA by using look-up table and sliding window technologies. The simulation results show that the new algorithm fully meet the performances of GSM/EDGE mobile communications. Furthermore, the digital scheme is suitable for large-scale integrated circuit design.