Invention Grant
- Patent Title: Subscriber unit for wireless digital subscriber communication system
- Patent Title (中): 无线数字用户通信系统用户单元
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Application No.: US394497Application Date: 1989-08-14
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Publication No.: US5008900APublication Date: 1991-04-16
- Inventor: David N. Critchlow , Moshe Yehushua , Graham M. Avis , Wade L. Heimbigner , Karle J. Johnson , George A. Wiley
- Applicant: David N. Critchlow , Moshe Yehushua , Graham M. Avis , Wade L. Heimbigner , Karle J. Johnson , George A. Wiley
- Applicant Address: PA King of Prussia
- Assignee: International Mobile Machines Corporation
- Current Assignee: International Mobile Machines Corporation
- Current Assignee Address: PA King of Prussia
- Main IPC: H04M1/00
- IPC: H04M1/00 ; H03B28/00 ; H03C3/00 ; H03D3/00 ; H04B1/40 ; H04B3/00 ; H04B7/00 ; H04J3/02 ; H04L25/03 ; H04L27/00 ; H04L27/18 ; H04L27/20 ; H04W84/16
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.
Public/Granted literature
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