Base stations for TDD telephony and methods for operating the same

• US 6,023,628 A
• Filed: 03/04/1996
• Issued: 02/08/2000
• Est. Priority Date: 08/05/1992
• Status: Expired due to Term

• Current Assignee: Elo Touchsystems Incorporated (Elo Touch Solutions, Inc.), PCS Wireless, LLC
• Original Assignee: PCS Wireless, LLC
• Inventors: Beasley, Andrew
• Primary Examiner(s): CUMMING, WILLIAM D
• Application Number:
  US08/610,391
• Time in Patent Office: 1,436 Days
• Field of Search: 379/56, 379/58, 379/60, 455/561, 455/562, 455/14, 455/54.1, 370/307, 370/280, 370/28.1
• US Class Current: 455/561
• CPC Class Codes: H04B 7/2615 using hybrid frequency-time division multiple access [FDMA-TDMA]

Abstract

A base station for a time division duplex (TDD) cordless telephone system has a frequency division duplex (FDD) transmit signal path for outputting FDD transmit signals, the transmit signal path including a transmit signal timing generator for controlling the timing of the transmit signals, and an FDD receive signal path for processing FDD receive signals input into the base station. The receive signal path includes a demodulator for demodulating the receive signals, a bit timer responsive to bit clock timing in the receive signals for controlling the timing of the receive signals in dependance on the receive signal bit clock timing and a data processor responsive to the demodulator and the bit timer for correspondingly varying the timing of the receive signals.

Claims

1. A base station for a time division duplex (TDD) cordless telephone system comprising:

a frequency division duplex (FDD) transmit signal path for outputting FDD transmit signals;

said transmit signal path including a transmit signal timing generator for controlling the timing of the transmit signals;

a frequency division duplex (FDD) receive signal path for processing FDD receive signals input into said base station;

said receive signal path including a demodulator for demodulating the receive signals, a bit timer responsive to bit clock timing in the receive signals for controlling the timing of the receive signals in dependance on the receive signal bit clock timing and a data processor responsive to said demodulator and said bit timer for correspondingly varying the timing of the receive signals.

2. A base station as claimed in claim 1, wherein said transmit signal path and said receive signal path comprise first means for processing the transmit signal and second means for processing the receive signal, said first and second means being embodied in a single micro-processor.

3. A base station for time division duplex (TDD) cordless telephony, comprising:

first processor means for processing frequency division duplex (FDD) transmit signals and transmitting the processed FDD transmit signal through a signal conduit;

said first processor means being provided with a transmit signal timer for controlling the timing of the transmit signals transmitted from said base station;

second processor means for processing frequency division duplex (FDD) receive signals and transmitting the processed receive signals from said base station to a public switched telephone network;

said second signal processor means comprising means for deriving signal timing from said receive signals for controlling the timing of the receive signals transmitted from said base station.

4. A base station for a time division duplex (TDD) cordless telephone system, comprising:

a transmit signal path;

said transmit signal path comprising an analog-to-digital converter for converting analog transmit signals from a public switched telephone network into digital transmit signals;

a timing generator;

a first signal processor means responsive to said timing generator for processing the digital transmit signals into frequency division duplex (FDD) transmit signals having a timing controlled by said timing generator; and

an RF modulator for modulating the FDD transmit signals for transmission from said base station; and

a receive signal path;

said receive signal path comprising an RF demodulator for demodulating FDD receive signals transmitted to said base station;

a symbol synchronizer and bit timer for deriving bit clock timing from the demodulated receive signal;

a second signal processing means responsive to said symbol synchronizer and bit timer for processing the demodulated receive signal in accordance with the bit clock timing derived from the receive signal; and

a digital-to-analog converter for converting the processed receive signal for transmission from said base station as an analog signal.

5. A base station as claimed in claim 4, wherein said first and second signal processor means are embodied as a single microprocessor.

6. A method operating a base station in a time division duplex (TDD) telephony, comprising the steps of:

receiving signals in the form of frequency division duplex (FDD) transmit signals from a public switched telephone network;

generating transmit signal timing;

processing the transmit signals in accordance with said transmit signal timing;

outputting the processed transmit signals from said base station;

receiving telephone signals in the form of FDD receive signals as input to said base station;

deriving signal timing form the receive signals;

processing the receive signals in dependence on the signal timing derived from the receive signals;

outputting the thus-processed receive signals from said base station to the public switched telephone network.

7. A method as claimed in claim 6, which includes employing the different frequencies for the transmit signals and the receive signals, and a common signal conduit for transmission of the transmit signals from, and transmission of the receive signals to said base station.

8. A method as claimed in claim 6, which includes employing the same frequency for both the transmit signals and the receive signals and separate signal conduits for transmission of the transmit signals from, and transmission of the receive signals to, said base station.