PURPOSE: A parallel hopping direct sequence/slow frequency hopping composite CDMA system is provided to obtain a low bit error rate by dividing an entire frequency bandwidth, selecting a partial bandwidth and transmitting a direct sequence spread signal in parallel. CONSTITUTION: A bandwidth spreader(300) receives a signal to be transmitted, and spreads the signal by multiplying a PN(Pseudo-random Noise) to it. SFH(Slow Frequency Hopping) units(311-31M) respectively receive the bandwidth-spread signal, multiply a carrier to the bandwidth-spread signal, and output it. Gate function generators(321-32M) respectively receive corresponding outputs of the SFHs(311-31M), and controls output of an applied gate function, that is, output of corresponding frequency hopping signals of sub-band. A combiner(330) combines a signal outputted from the gate function generators(321-32M) and outputs it. The signal outputted from the combiner(330) is outputted through an RF(Radio Frequency) transmitter.
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