Reconfigurable digital baseband modulation for wireless computer communication

Abstract

A reconfigurable all digital modulation technique that enables high speed data transmission (up to 16 Mb/s) has been developed for applications to wireless computer data communications. A low power, single chip digital implementation and experimental results of a modem baseband processor are presented. The digital modulator accommodates memory or memoryless modulation methods including K. Feher's (1991) Quadrature Phase Shift Keying (FQPSK), Offset Quadrature Phase Shift Keying (OQPSK), Superposed Quadrature Amplitude Modulation (SQAM), Minimum Shift Keying (MSK), and /spl pi//4-QPSK to list a few. The design was tested at 1 Mb/s and 4 Mb/s and consumed less than 35 mW of active power with a typical standby power of less than 150 /spl mu/W-making it well suited for portable designs. Carrier modulated test results show high spectral efficiency in a nonlinear amplified (NLA) channel. A new method of in-system reconfiguration using a microcontroller and an IEEE standard 1149.1 Joint Test Application Group (JTAG) interface is also presented. This technique has applications in in-field (remote) service. Since the design is completely digital with low complexity, it is suitable for the first generation of wireless modem systems, giving prospects for future personal communication services (PCS) data transmission applications. >