Tone allocation in multipoint-to-point communication using orthgonal frequency division multiplexing
US7355963B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 2007 |
| Grant date | Apr 8, 2008 |
| Priority date | — |
| Expiry date | Apr 20, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D30/50
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Systems for tone allocation are provided. In one embodiment, a system comprises: a plurality of remote units and a host including a demodulator. Each remote transmits an upstream OFDM signal using a multiple access scheme to the host using an OFDM waveform. The host receives the upstream OFDM signals, the tones of the upstream signals substantially orthogonal when received at the host. Portions of upstream OFDM signals from at least two remotes arrive at the host at the same time. The host demodulates said portions. At least one remote transmits to the host using a first tone allocated by the host. The host sends an adjustment signal to the remote to adjust the timing of transmissions to improve orthogonality of the OFDM waveform. After the remote has begun transmission using the first tone but before the remote has completed its transmission, the host allocates to the remote a different tone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.