A SINGLE-CHIP 12.7-MCHIPS/S DIGITAL IF BPSK DIRECT-SEQUENCE SPREAD-SPECTRUM TRANSCEIVER IN 1.2-MU-M CMOS

This paper describes a fully integrated digital spread spectrum transceiver chip fabricated through MOSIS in 1.2 mu m CMOS. It includes a baseband spread spectrum transmitter and a coherent intermediate frequency (LF) receiver consisting of a Costas loop, an acquisition loop for the pseudo-noise (PN) sequence, and a clock recovery loop with a 406.4 MHz on-chip numerically controlled oscillator (NCO), The transceiver is capable of operating at a maximum IF sampling rate of 50.8 MS/s and a maximum chip rate of 12.7 Mchips/s (Mcps) with selectable data rates of 100, 200, 400, and 800 kbps, At the maximum operating speed of 50.8 MS/s, it dissipates 1.1 W, In an additive white Gaussian noise channel the IF receiver achieves a receiver output SNR within 1 dB of theory and can acquire code with a wide range of input SNR from -17 dB to over 30 dB, The transceiver chip has been interfaced to an RF up/down converter to demonstrate a wireless voice/data/video link operating in the 902-928 MHz band.