Subscriber unit for wireless digital subscriber communication system
US5008900A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 14, 1989 |
| Grant date | Apr 16, 1991 |
| Priority date | — |
| Expiry date | Aug 14, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2025/03477
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A subscriber unit for wireless communication with a base station in a wireless subscriber communication system includes a FIR chip, a DIF (digital intermediate frequency) chip, a single processor chip and a radio. The processor chip transcodes a digital voice input signal to provide digital input symbols; demodulates an output signal received from the base station to provide digital output symbols; and synthesizes a digital voice output signal from the digital output symbols. The FIR chip FIR filters the digital input symbols and generates timing signals for timing the transcoding and synthesizing operations in the processor chip. The DIF chip digitally synthesizes a digital intermediate frequency signal by direct digital synthesis (DDS) and modulates the digital intermediate frequency signal with the filtered input symbols to provide a modulated intermediate frequency input signal. The radio further processes the modulated input signal for transmission to the base station.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.