Method and apparatus for down conversion within an X-DSL receiver
US6512739B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 2001 |
| Grant date | Jan 28, 2003 |
| Priority date | — |
| Expiry date | Feb 13, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L5/14
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The current invention provides a method and apparatus for downconverting received digital data from the elevated frequencies at which the data is modulated. Various multi-tone communications systems (such as DMT in wire-line communication or OFDM in wireless communication) operate by up-converting output of the modulated signal at the output of the IFFT from baseband to a higher center frequency. Therefore, at the receiver, the inverse operation is required. At the receiver the signal must be down-converted to baseband before being available for processing by the FFT. In this invention, a simplified converter is provided, where the complex multiplication required by prior art downconverters is avoided, thus simplify the downconversion process and reducing power requirements. The apparatus and method may be implemented on a physical modem or a logical modem with the logical modem including a digital signal processor (DSP) coupled to an analog front end (AFE). The communication medium may include: wired, wireless and optical. The present invention provides a signal processing architecture that supports scalability of CO/DLC/ONU resources, and allows a significantly more flexible hard…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.