초록 ▼

A novel and improved method and apparatus for high rate CDMA wireless communication is described. In accordance with one embodiment of the invention, a set of individually gain adjusted subscriber channels are formed via the use of a set of orthogonal subchannel codes having a small number of PN spr

A novel and improved method and apparatus for high rate CDMA wireless communication is described. In accordance with one embodiment of the invention, a set of individually gain adjusted subscriber channels are formed via the use of a set of orthogonal subchannel codes having a small number of PN spreading chips per orthogonal waveform period. Data to be transmitted via one of the transmit channels is low code rate error correction encoded and sequence repeated before being modulated with one of the subchannel codes, gain adjusted, and summed with data modulated using the other subchannel codes. The resulting summed data is modulated using a user long code and a pseudorandom spreading code (PN code) and upconverted for transmission. The use of the short orthogonal codes provides interference suppression while still allowing extensive error correction coding and repetition for time diversity to overcome the Raleigh fading commonly experienced in terrestrial wireless systems. In the exemplary embodiment of the invention provided, the set of sub-channel codes are comprised of four Walsh codes, each orthogonal to the remaining set and four chips in duration. The use of four sub-channels is preferred as it allows shorter orthogonal codes to be used, however, the use of a greater number of channels and therefore longer codes is consistent with the invention.

대표청구항 ▼

[ We claim:] [1.] A method for generating modulated data for transmission from a first subscriber unit in a set of subscriber units to a base station in communication with the set of subscriber units comprising the steps of:a) modulating first data with a first orthogonal code to generate first chan

[ We claim:] [1.] A method for generating modulated data for transmission from a first subscriber unit in a set of subscriber units to a base station in communication with the set of subscriber units comprising the steps of:a) modulating first data with a first orthogonal code to generate first channel data;b) modulating second data with a second orthogonal code to produce second channel data;c) summing said first channel data and said second channel data to generate summed data;d) modulating said summed data with a long code to generate the modulated data;e) gain adjusting said first channel data by a first amount; andf) gain adjusting said second channel data by a second amount.