Direct conversion transceiver design in the 863-870-Mhz band Application: Wireless sensor network

Simulation results of a 863-870-MHz frequency-hopped spread-spectrum transceiver with binary frequency shift keying (BFSK) modulation at 20 kb/s for wireless sensor applications is presented. The various blocks parameters of the transmit/receive RF front end like noise figure (NF), gain, 1 dB compression point (P-1dB), and IIP3 are simulated and optimized to meet transceiver specifications. The receiver simulations show 51.1 dB conversion gain, -7 dBm IIP3, -15 dB return loss (S11) and 10 dB NF. The transmitter simulations show an output ACPR (Adjacent Channel Power Ratio) of -22 dBc, 3.3 dBm P-1dB of PA and transmitted power of 0 dBm. The transceiver simulations show an RMS frequency error of 1.45 Khz. Correlating BFSK detector and Arctangent-differentiated BFSK demodulator have been chosen and their BER performances have been co simulated with the analog receiver. The receiver achieves a BER of 10 at 10.5 dB of EbtoNo. Key-Words: Wireless sensor, FHSS, Direct conversion transmit/receive RF front , ACPR, P-1dB, NF, IIP3, RMS frequency error, Conversion gain. Arctan-differentiated demodulator,BER