Method and apparatus for post-detection maximum ratio combining with antenna diversity in an orthogonal frequency division multiplexing (OFDM) communication system
US6842421B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 17, 1999 |
| Grant date | Jan 11, 2005 |
| Priority date | — |
| Expiry date | Sep 17, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2647
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A novel antenna diversity technique for OFDM receivers is disclosed. A method and apparatus are disclosed for combining in the frequency domain the various signals received on each of the multiple antennas in an OFDM communication system. At the OFDM transmitter, the transmitted signal is differentially encoded over frequency, as opposed to time, to differentially encode the transmitted signal in the frequency domain with respect to consecutive bins (OFDM sub-carriers). The OFDM receiver processes a signal received on a number of diversity branches and combines the received signals using a post-detection combining technique after differential decoding. Each frame is independently processed by a differential decoder and then delayed to align each symbol in a given frame. The post-detection combining of the frame data inherently scales the received samples and thereby implements an optimal maximum ratio combining mechanism. Unlike conventional maximum ratio combining techniques, the faded bins are scaled individually by the differential decoder, based on their own power levels rather than the overall power of the OFDM frame. Thus, bins with higher magnitudes will be weighted more hea…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.