A LOW-POWER BASEBAND RECEIVER IC FOR FREQUENCY-HOPPED SPREAD-SPECTRUMCOMMUNICATIONS

A baseband receiver IC which will be incorporated into a low-power fre quency-hopped spread spectrum (FH/SS) transceiver for 902-928 MHz ISM band applications is presented, The chip performs noncoherent binary/q uaternary frequency shift keying (FSK) demodulation, equal-gain divers ity combining of dual antenna branches, and symbol and frequency synch ronization. The chip also accommodates variable data rates from 2 to 1 60 kb/s, programmable hop rates, and tunable bandwidth loop filters, T he core area of the 1-mu m CMOS chip is 3.9 mm x 3.9 mm with a power c onsumption of 4.5 mW at 10 MHz from a 3-V supply. A baseband transceiv er system utilizing this receiver chip for the prototype handset to de monstrate a point-to-point communication link is also described, Two X ILINX FPGA chips were used to implement the remainder of the baseband transceiver functions, including frequency control logic for FSK modul ation, acquisition control, data framing, symbol interleaving and dein terleaving, and interface control for data and voice.