Patent ID: 6657985
Filing Date: 2003-12-02
Classification: H04B,H04J

Abstract:
A code division multiple access (CDMA) communication system comprising:a transmitter for modulating input digital signals using an orthogonal code hopping multiple access technique and transmitting the modulated digital signals, said transmitter comprising: a hopping orthogonal code generator for generating orthogonal codes according to a hopping pattern prescribed between the transmitter and the receiver, wherein said hoping orthogonal code generator comprises an orthogonal code generator for generating the orthogonal codes according to the hopping pattern, and a hopping controller connected to said orthogonal code generator for generating said hopping pattern; a plurality of mixers each connected to the hopping orthogonal code generator, for multiplying the input digital signals by corresponding orthogonal codes; a summer connected to outputs of the mixers, for summing output signals of the mixers; a pseudo noise sequence generator for band-spreading the modulated digital signals; a modulator for modulating an output signals of the summer; an antenna; and a power amplifier for amplifying an output signal of the modulator and transmitting the amplified signal through the antenna; and a receiver for receiving the digital signals using the orthogonal code hopping multiple access technique and restoring the digital signals.