System and method for optimizing high speed data transmission
US5991336A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 17, 1997 |
| Grant date | Nov 23, 1999 |
| Priority date | — |
| Expiry date | Oct 17, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/033
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The present invention is drawn to a system and method for transmitting a data signal using digital subscriber loops in an expanded frequency band. According to the present invention, an encoder receives a data signal to be transmitted to a second modem. The encoder generates both an in-phase and a quadrature signal based on the data signal. Both the in-phase signal and the quadrature signals are then processed by a signal precoder in preparation for transmission across the channel. Next, the in-phase and quadrature signals are processed by digital filters to produce signals of limited bandwidth which can be transmitted across the channel. The coefficients of the digital filter are chosen such that the resulting filtered in-phase and quadrature signals are transmitted in an expanded bandwidth. The quadrature signal is filtered so as to be orthogonal to the in-phase signal. Thereafter the filtered signals are added and then converted to an analog signal which is transmitted to the second modem. The second modem features signal recovery circuitry which will process the expanded bandwidth resulting in a baseband which features an increased signal to noise ratio making the data transmis…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.