A multicarrier GMSK modulator for base station

In conventional base station solutions, transmitted carriers are combined after power amplifiers (PAs). This paper describes an architecture in which four GMSK modulated signals are combined in the digital domain. This saves a large number of analog components, many of which require production tuning. Consequently, an expensive and tedious part of manufacturing is eliminated. The proposed multicarrier GMSK modulator does not use an analog I/Q modulator. Therefore the difficulties of adjusting the dc offset, the phasing and the amplitude levels between the in-phase and quadrature phase signal paths are avoided.