Bandwidth Efficient Gaussian Minimum Frequency-Shift Keying Approach for Software Defined Radio

This paper proposes a bandwidth efficient Gaussian Minimum Frequency-Shift Keying (GMSK) approach for software defined radio (SDR) platforms. The proposed demodulator applies a Gaussian filter with impulse response longer than the symbol period, which results in higher spectral efficiency. On the other hand, an impulse response longer than the symbol period causes inter-symbol interference (ISI), which may compromise the bit error rate (BER) performance. To address this issue, this paper proposes a new demodulation technique that takes into account the previous received bit at the demapping process. The proposed approach has been implemented and evaluated in Matlab and further described in VHDL and synthetized in a DIGILENT ZYBO ZynqTM - 7010 development board. Results show that the proposed method presents significantly reduced bit error rate when compared with other methods in the literature.