Patent Number: 7,085,307

Title: Methods and apparatus for transmitting data over a CDMA network

Abstract: The use of cyclic prefixes with OFDM transmissions is known. Typically the prefix length is chosen to be at least as long as the duration of significant multipath in the transmission channel. However, OFDM has disadvantages in terms of DSP load and transmitter power amplifier specifications. The use of a cyclic prefix with periodic CDMA codes has been found to yield equivalent performance in terms of orthogonality in a dispersive channel and yet overcomes the disadvantages of cyclicly prefixed OFDM transmissions. Examples are given of Walsh Hadamard binary periodic codes.

Inventors: Hudson; John E (Stansted, GB)

Assignee: Nortel Networks Limited

International Classification: H04L 27/30 (20060101)

Expiration Date: 8/01/02018