Multicode direct sequence spread spectrum
USRE37802E1 · kind E1 · reissue
Assignee
Inventors
Key dates
| Filing date | Sep 10, 1998 |
| Grant date | Jul 23, 2002 |
| Priority date | — |
| Expiry date | Sep 10, 2018 |
Classification
- Technology area (CPC —)General
Abstract
In this patent, we present MultiCode Direct Sequence Spread Spectrum (MC-DSSS) which is a modulation scheme that assigns up to N DSSS codes to an individual user where N is the number of chips per DSSS code. When viewed as DSSS, MC-DSSS requires up to N correlators (or equivalently up to N Matched Filters) at the receiver with a complexity of the order of N2 operations. In addition, a non ideal communication channel can cause InterCode Interference (ICI), i.e., interference between the N DSSS codes. In this patent, we introduce new DSSS codes, which we refer to as the “MC” codes. Such codes allow the information in a MC-DSSS signal to be decoded in a sequence of low complexity parallel operations which reduce the ICI. In addition to low complexity decoding and reduced ICI. MC-DSSS using the MC codes has the following advantages: (1) it does not require the stringent synchronization DSSS requires, (2) it does not require the stringent carrier recovery DSSS requires and (3) it is spectrally efficient.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.