Upsampling filter having one-bit multipliers for multiple spread-data streams
US6603804B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 1, 1999 |
| Grant date | Aug 5, 2003 |
| Priority date | — |
| Expiry date | Oct 1, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H17/0223
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A transmit portion of a WB-CDMA transceiver generates one or more spread data streams having values represented by a single bit, allowing for filtering of spread and combined data streams with a root raised cosine (RRC) filter employing single-bit multipliers. The RRC filter is a digital filter that i) employs multiplication of two values in which the length of at least one value is one bit; ii) is preferably implemented with muxs or a simple logic operator; and iii) may employ upsampling and modulation encoding of filter coefficients to reduce the coefficient length to, for example, one bit. The RRC filter may be an FIR filter having either one-bit or multi-bit coefficients, and apply RRC filtering to a spread user stream either before or after the spread user streams are combined. For some implementations, RRC filters are employed to filter each spread user stream prior to combining several processed user steams. For other implementations, the multi-bit valued data stream representing the combined user streams is upsampled to form an upsampled data stream of single-bit values, and RRC filtering is then applied to the upsampled data stream. Alternatively, implementations may use u…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.