Simulation Study of a GMSK Modem

• Main Authors: Hsu, Tsung-Ming, 許宗銘
• Other Authors: Thomas T. Fang
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/04345325930409738750

碩士 === 國立中正大學 === 電機工程學系 === 86 === Gaussian minimum shift keying (GMSK)with constant envelope and compact spectrum is an attractive modulation technique for satellite communications and mobile radio applications. Some communication systems such as GSM and DECT, use GMSK as their modulation method. Although GMSK have many advantages, it suffers from significant intersymbol interference(ISI) because of lower bandwidth (the lower the bandwith, the more the ISI) and the demodulator becomes very important. The demodulator roughly includes the detector and the symbol timing and frequency offset estimator. In this paper, we introduce some differential detectors and the timing and frequency offset estimator . Due to the advantages of the time-division multiple access(TDMA) and it has been the standard of some communication systems, the simulation of the performance also follows this channel architecture. We will simulate the systems in AWGN channel and fading channel to test the system performance especially the ability of symbol timing and frequency offset estimation in GMSK signal.