Method for initialization of per tone frequency domain equalizer (FEQ) through noise reduction for multi-tone based modems
US7406125B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 2004 |
| Grant date | Jul 29, 2008 |
| Priority date | — |
| Expiry date | Feb 2, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2025/03598
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An improved per-tone FEQ method with a noise reduction technique using periodic training pilot tones increases the throughput for long-reached modems. This method can reduce the noise effects in estimating FEQ equalizer coefficients. Each per-tone FEQ can be estimated by using the periodic training signals and an averaging technique to remove noise from each sub-channel (EQN. VI). After solving the system equations (EQN. IV), per-tone equalization coefficients of the FEQ equalizer for each group can be combined to obtain the optimized results in the form of the Toeplitz matrix (EQN. V). Each element within the Toeplitz matrix can be derived from the averaging technique used to remove noise from each sub-channel (EQN. VI). To demodulate a signal with the Toeplitz matrix, an inverse of every element in a row of the Toeplitz matrix is taken and multiplied by the sending signal which creates an N Log N matrix.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.