10 mbit/s CFO-SS (carrier frequency offset-spread spectrum) system using 2.4 GHz ISM band

The design of wireless communications systems with a transmission rate of 10 Mbit/s is presented for the 2.4 GHz Japanese ISM band, in which a spread spectrum technique named “CFO-SS” scheme is employed. In the CFO-SS system, a single PN code is commonly assigned to all the synchronized multiplexed carriers, and the frequency separation between carriers is determined by the transmission rate of each carrier. The detailed principle of the CFO-SS scheme, together with a configuration of the 10 Mbit/s CFO-SS system, is discussed. The bit and packet error performance under severe multipaths environments with/without the RAKE receiver, degradation by channel bandwidth limitations, frequency inaccuracy of the hardware and CCI is presented. The simulation results confirm that sufficient performance for wireless LAN systems using the 2.4 GHz ISM band is obtained under typical indoor environments by the 10 Mbit/s CFO-SS system