SS-CDMA flexible wireless network: approximately synchronized CDMA modem for uplink

We have proposed an intracell uplink of a spread-spectrum code-division multiple-access (SS-CDMA) flexible wireless network based on approximately synchronized (AS) CDMA. Since the AS-CDMA has no co-channel interference, complicated transmission power control is not required. A modem of the AS-CDMA has been designed and implemented for the Japanese 2.4 GHz industrial, scientific and medical band. Using the implemented modem, the degradation of E/sub b//N/sub 0/ from the theoretical limit is 1.0 dB at a bit error rate (BER) of 10/sup -3/. Under a 2-user environment, the degradation of carrier-to-noise ratio from the case without undesired signal is 0.5 dB at a BER of 10/sup -3/ when the desired-to-undesired signal ratio is -20.3 dB.