Nokia Mobile Phones Limited

Rodolfo Vadillo

Ari T Hottinen

Zhi-Chun Honkasalo

John W Noneman

Mika Laukkanen

Jussi Kahtava

A method and apparatus for varying the data transmission rate of a code division multiple access (CDMA) telecommunications system. The method and apparatus may be implemented into an existing system operating according to a standard designed for a base data transmission while utilizing the Walsh modulator length, the data transmission frame structure, the channel encoding scheme, or the I/Q modulation level of the existing system. Serial data is input to a transmitter/modulator at a data rate which is higher than the base data transmission rate. The serial data is received over a time period having a duration equal to the duration of the transmission frame and demultiplexed into a plurality of sets of input data. Each of the plurality of sets of input data is then processed in one of a plurality of subchannels using the system channel encoding and interleaving scheme to generate a plurality of sets of processed data. A output serial data stream is then generated by multiplexing the plurality of sets of processed data from the subchannels together. The serial output stream is generated so that the originally received serial data included in the serial output data stream, is generated at the first data rate. The serial output data stream is spread to generate at least one spread data stream and is then transmitted on the channel during a second time period having a duration equal to the duration of the transmission frame, so that the serial data included in the at least one spread data stream is transmitted at the first data rate.

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Camberley, United Kingdom

Rodolfo Vadillo