Baseband signal processing network modulator, transmit amplifier and antenna systems for plurality of baseband signals and for providing cross-correlated in-phase and quadrature-phase processed and filtered baseband signals to one or more quadrature modulators for modulation. Time Division Multiple Access (TDMA) cross-correlated processed Time Constrained Signal (TCS) waveforms and Long Response (LR) filtered in-phase (I) and quadrature-phase (Q) baseband signals and spread spectrum Code Division Multiple Access (CDMA) or processed Code Division Multiplexed (CDM) signal, third generation (3G) systems, including TDMA Gaussian Minimum Shift Keying (GMSK) modulated systems. A signal selector device for selecting and providing one of the modulated signals to a set of one or more transmit amplifiers to amplify the selected modulated signal. Transmit amplifiers operated in a Non-Linearly Amplified (NLA) mode for amplification of processed TDMA modulated signals and amplifiers operated in a linearly amplified mode for amplification of processed spread spectrum modulated signals.