A novel modulation/RF architecture for long battery life-time PCS mobile units

A novel modulation/RF architecture is proposed for digital cellular and PCS applications to improve the system power efficiency. By introducing controlled cross-correlation to the I and Q channels in an offset QPSK system and employing modified baseband filtering techniques, the proposed modulation architecture provides a constant envelope modulated signal and improves the power efficiency by 4-7 dB as compared to conventional QPSK. By implementing this new system architecture in a cellular phone, portable computer, or other PCS mobile units, the battery life time could be significantly improved.