Delay insensitive base station-to-handset interface for radio telephone systems
First Claim
1. A method of exchanging telephone signals between a basestation and a mobile cordless time division duplex (TDD) handset, comprising the steps of:
- passing transmit signals as frequency division duplex (FDD) signals from said basestation to a remote antenna driver;
converting said transmit signals to time division duplex (TDD) signals at said remote antenna driver;
broadcasting said time division duplex signals to said handset;
receiving at said remote antenna driver TDD receive signals broadcast by said handset, said TDD receive signals including bit clock timing;
converting said TDD receive signals to FDD receive signals at said remote antenna driver;
passing said FDD receive signals to said basestation; and
deriving bit clock timing from said FDD receive signals at said basestation and employing said bit clock timing to process said FDD receive signals.
11 Assignments
0 Petitions
Accused Products
Abstract
A cordless telephone system, employs a remote antenna driver for converting TDD receive signals, broadcast from a cordless handset operating in a TDD (time division duplex) mode, to FDD (frequency division duplex) receive signals and for converting FDD transmit signals into TDD transmit signals and broadcasting the TDD signals to said handset. A base station operates in an FDD mode for supplying the FDD transmit signals to the remote antenna driver and for receiving the FDD receive signals from the remote antenna driver. The base station has a transmit signal path for supplying the FDD transmit signals and a receive signal path separate from the transmit signal path. The transmit signal path includes a timing generator for timing the FDD transmit signals and the receive signal path includes demodulator for demodulating the FDD receive signals symbol synchronizer and bit timer for deriving bit clock timing pulses from the FDD receive signals for controlling the timing of the receive signal path, whereby the timing of the receive signal path is controlled by the handset.
75 Citations
7 Claims
-
1. A method of exchanging telephone signals between a basestation and a mobile cordless time division duplex (TDD) handset, comprising the steps of:
-
passing transmit signals as frequency division duplex (FDD) signals from said basestation to a remote antenna driver; converting said transmit signals to time division duplex (TDD) signals at said remote antenna driver; broadcasting said time division duplex signals to said handset; receiving at said remote antenna driver TDD receive signals broadcast by said handset, said TDD receive signals including bit clock timing; converting said TDD receive signals to FDD receive signals at said remote antenna driver; passing said FDD receive signals to said basestation; and deriving bit clock timing from said FDD receive signals at said basestation and employing said bit clock timing to process said FDD receive signals.
-
-
2. A method of exchanging telephone signals between a basestation and a mobile cordless time division duplex (TDD) handset, comprising the steps of:
-
passing transmit signals from said basestation to a remote antenna driver; broadcasting said transmit signals from said remote antenna driver to said mobile handset; receiving at said remote antenna driver signals broadcast by said handset, said receive signals including bit clock timing; passing said receive signals from said remote antenna driver to said basestation; and deriving bit clock timing from said receive signals at said basestation; and employing said bit clock timing to process said receive signals at said basestation; said transmit signals and said receive signals being passed between said basestation and said remote antenna driver through separate signal paths at the same frequency.
-
-
3. A basestation for a time division duplex (TDD) cordless telephone system, comprising:
-
a transmit signal path including an analog-to-digital converter for connection to a public switched telephone network; a timing generator; a first data processor for providing frequency division duplex (FDD) transmit signals in response to digital signals from said analog-to-digital converter and timing pulses from said timing generator; an RF modulator for modulating the FDD transmit signals; said basestation further comprising a receive signal path; and said receive signal path including; a RF FDD receive signal demodulator; a symbol synchronizer and bit timer responsive to bit clock timing pules in the receive signals; a second data processor responsive to said symbol synchronizer and bit timer and said RF demodulator; and a digital-to-analog converter for supplying an analog signal to the public switched telephone network in response to said second data processing means.
-
-
4. A time division duplex (TDD) cordless telephone system, comprising:
-
a cordless handset operating in a TDD mode; a remote antenna driver for converting TDD receive signals broadcast from said handset into frequency division duplex (FDD) receive signals and for converting FDD transmit signals into TDD transmit signals and broadcasting the TDD signals to said handset; a basestation operating in an FDD mode; and a signal conduit connecting said basestation to said remote antenna driver; said basestation comprising an FDD transmit signal path for transmission of the FDD transmit signals to said remote antenna driver and an FDD receive signal path for the FDD receive signals from said remote antenna driver; said transmit signal path including an FDD transmit signal timer; and said receive signal path including an FDD receive signal demodulator, a receive signal timer responsive to bit clock timing pulses in the FDD receive signals and a receive signal processor responsive to said demodulator and said receive signal timer. - View Dependent Claims (5)
-
-
6. A time division duplex (TDD) telephone system, comprising:
-
a TDD handset; a frequency division duplex (FDD) basestation; a remote antenna driver responsive to FDD transmit signals from said basestation and TDD receive signals from said handset; and a signal conduit connecting said basestation to said remote antenna driver; said basestation including a transmit signal path, a transmit signal processor in said transmit signal path, a receive signal path, a bit clock timer responsive to bit clock timing pulses in said receive signals and a receive signal processor in said receive signal path, said receive signal processor being operable, in response to timing from said bit clock timer, independently of said transmit signal processor.
-
-
7. A time division duplex (TDD) cordless telephone system, comprising:
-
a TDD cordless handset; a frequency division duplex (FDD) basestation; a remote antenna driver for broadcasting TDD transmit signals to said handset in response to FDD transmit signals from said basestation and for providing FDD receive signals to said basestation in response to TDD receive signals from said handset; and a signal conduit connecting said basestation to said remote antenna driver; said basestation including; an analog-to-digital converter for providing digital transmit signals in response to analog transmit signals from a public switched telephone network; an FDD transmit signal timing generator; a first data processor means for providing the FDD transmit signals in response to the digital transmit signals from said analog-to-digital converter and in response to said timing generator; and an RF modulator for modulating the FDD transmit signals; said basestation further including an RF demodulator for demodulating the FDD receive signals from said remote antenna driver; a symbol synchronizer and bit timer for deriving receive bit clock timing and symbol clock timing from the demodulated FDD receive signals; second data processor means for processing the output of said symbol synchronizer and bit timer in accordance with the receive bit clock timing; and a digital-to-analog converter for supplying an analog signal to the public switched telephone network in response to the output of said second data processing means.
-
Specification