United States Patent 7,876,806
Pan , et al. January 25, 2011
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Orthogonal frequency division multiplexing-code division multiple access system
Abstract
An orthogonal frequency division multiplexing (OFDM)-code division multiple access (CDMA) system is disclosed. The system includes a transmitter and a receiver. At the transmitter, a spreading and subcarrier mapping unit spreads an input data symbol with a complex quadratic sequence code to generate a plurality of chips and maps each chip to one of a plurality of subcarriers. An inverse discrete Fourier transform is performed on the chips mapped to the subcarriers and a cyclic prefix (CP) is inserted to an OFDM frame. A parallel-to-serial converter converts the time-domain data into a serial data stream for transmission. At the receiver, a serial-to-parallel converter converts received data into multiple received data streams and the CP is removed from the received data. A discrete Fourier transform is performed on the received data streams and equalization is performed. A despreader despreads an output of the equalizer to recover the transmitted data.
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Inventors: Pan; Jung-Lin (Selden, NY), Zhang; Guodong (Farmingdale, NY), Tsai; Yingming (Boonton, NJ)
Assignee: InterDigital Technology Corporation (Wilmington, DE)
Appl. No.: 11/385,168
Filed: March 21, 2006
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Related U.S. Patent Documents
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Application Number Filing Date Patent Number Issue Date
60664868 Mar., 2005
60665442 Mar., 2005
60665811 Mar., 2005
60666140 Mar., 2005
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Current U.S. Class: 375/130 ; 375/260
Current International Class: H04B 1/707 (20060101)
Field of Search: 375/260,130,140,146,147,259
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