Multicode spread spectrum communications system
US6320897A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 3, 1999 |
| Grant date | Nov 20, 2001 |
| Priority date | — |
| Expiry date | Sep 3, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/709
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
MultiCode Spread Spectrum (MCSS) is a modulation scheme that assigns a number N of Spread Spectrum (SS) codes to an individual user where the number of chips per SS code is M. When viewed as Direct Sequence Spread Spectrum, MCSS requires up to N correlators (or equivalently up to N Matched Filters) at the receiver with a complexity of the order of NM operations. In addition, a non ideal communication channel can cause InterCode Interference (ICI), i.e. interference between the N SS codes. In this patent, we introduce three new types of MCSS. MCSS Type I allows the information in a MCSS signal to be detected using a sequence of partial corrrelations with a combined complexity of the order of M operations. MCSS Type II allows the information in a MCSS signal to be detected in a sequence of low complexity parallel operations which reduce the ICI. MCSS Type III allows the information in a MCSS signal to be detected using a filter suitable for ASIC implementation or on Digital Signal Processor, which reduces the effect of multipath. In addition to low complexity detection and reduced ICI, MCSS has the added advantage that it is spectrally efficient.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.