Patent ID: 7570705
Filing Date: 2009-08-04
Classification: H04L

Abstract:
1. A Gaussian Minimum Shift Keying (GMSK) modulator comprising: a dual-port memory configured to respectively output in-phase waveform data and quadrature phase waveform data to a first port and a second port in response to an in-phase waveform address signal and a quadrature phase waveform address signal, the in-phase waveform data and quadrature phase waveform data being stored in the dual-port memory; an address generator configured to generate the in-phase waveform address signal and the quadrature phase waveform address signal based on a differential encoded bit stream; and a signal provider configured to select one of the in-phase waveform data and the quadrature phase waveform data in response to the differential encoded bit stream, and configured to output a continuous GMSK in-phase channel signal and a continuous GMSK quadrature phase channel signals, wherein the address generator includes: a serial-to-parallel converter configured to output parallel data having at least one previous bit of the differential encoded bit stream, a present bit of the differential encoded bit stream and at least one next bit of the differential encoded bit stream; a pattern selector configured to generate at least one waveform pattern selection signal for designating one of the in-phase and quadrature phase waveform pattern samples in response to the present bit; an in-phase address generator configured to generate an in-phase address signal that sequentially designates each of sample values of the in-phase and quadrature phase waveform pattern samples selected by the at least one waveform patter selection signal and a quadrature phase address generator configured to generate a quadrature phase address signal that designates in a reverse sequence each of The sample values of the in-phase and quadrature phase waveform pattern samples selected by the at least one waveform pattern selection signal.