Channel tracking in an orthogonal frequency-division multiplexing system
US8675744B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 24, 2008 |
| Grant date | Mar 18, 2014 |
| Priority date | — |
| Expiry date | Apr 14, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2676
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A receiver determines phase and frequency information from data signals that carry information from a transmitter to a receiver, instead of or in addition to, information from control signals. In a specific embodiment, the information is obtained from data signals modulated as a binary phase-shift keying (“BPSK”) waveform by demodulation. Other phase-shift keyings might be used instead. Encoded information might be recovered in received OFDM packets by receiving OFDM subcarriers modulated with the two low data rates supported by IEEE 802.11 standard(s) wherein the subcarriers encoding the packet are modulated using binary phase shift keying and the encoding information is at a zero phase or a π (pi) phase offset on each of the subcarriers. Determining the carrier frequency might be done by calculating the square of each of subcarrier signal and/or determining the phase offset of the subcarriers even with information modulated onto the subcarriers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.