发明授权
- 专利标题: Spread spectrum transmitter and communications system using multiple spreading codes
- 专利标题(中): 扩频发射机和通信系统使用多个扩展码
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申请号: US432907申请日: 1995-05-01
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公开(公告)号: US5790591A公开(公告)日: 1998-08-04
- 发明人: Robert Gold , Robert C. Dixon
- 申请人: Robert Gold , Robert C. Dixon
- 申请人地址: CO Colorado Springs
- 专利权人: Omnipoint Corporation
- 当前专利权人: Omnipoint Corporation
- 当前专利权人地址: CO Colorado Springs
- 主分类号: H04B1/707
- IPC分类号: H04B1/707 ; H04J14/00 ; H04L7/04 ; H04K1/00
摘要:
A spread spectrum transmitter for generating a plurality of spread spectrum codes comprises a shift register having a plurality of stages, with a plurality of tap sets connected to selected ones of said stages. Each tap set defines a different spread spectrum code, which may be maximal or non-maximal. Outputs from the tap sets are combined using exclusive-OR gates and fed back to through a table of logic gates to the input of the shift register. A serial data register is loaded from a data stream and clocked periodically into a parallel data register. The parallel data register corresponds to a data symbol and is connected to the table, whereby one of the spread spectrum codes at a time is selected. A code portion of the spread spectrum code up to a designated length is generated for each data symbol. More than one code portion may be simultaneously sent using offset quadrature phase shift keying. A receiver may detect the code portion or code portions sent by delaying the received signal and combining it with a plurality of delayed versions thereof, the delay period for each delayed version corresponding to the tap locations in the tap set of the transmitter shift register.
公开/授权文献
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