A low power demodulator LSIC for personal communications: high performance coherent detection demodulator

This paper presents a low power coherent π/4-shift QPSK demodulator LSIC for personal communication systems in Japan. The developed LSIC, implemented on a CMOS 0.8 μm standard cell with 2-V operation, achieves better frame error rate performance and lower power consumption than conventional demodulators. It uniquely employs (1) a reverse-modulation carrier recovery scheme with a -π/4 signal-phase rotator and a band-width-varied carrier filter, (2) a clock recovery scheme using initial clock phase estimation, (3) a fully digital orthogonal detection scheme suitable for low power consumption, and (4) a burst detection scheme using phase information in preamble. Performance evaluation confirms that the demodulator LSIC reduces the irreducible frame error rate by 40%, and achieves an Eb/No improvement of 3 dB at the frame error rate of 10% compared with differential detection under the Rayleigh fading channel common in personal communication