Transverter control mechanism for a wireless modem in a broadband access system
View Patent ↗A system and method for controlling a transverter from a wireless modem unit (WMU). A WMU delivers a control signal to a transceiver. This signal is outside the IF signal data range (preferably below 11 MHz). The signal is carried on the cable between the transceiver and the WMU. This signal is detected by the transceiver, and determines the timing and the control information. The signal is ASK modulated to enable low data rate transfer of messages between the WMU and the transceiver. The control signal is detected at the transverter using a detector circuit. Additionally, specific transverter detection circuits are disclosed to detect the control signal.
1. A transverter control system comprising:
a diplexer connected to a wireless modem unit (WMU) and receiving a downstream signal and outputting an upstream signal;
a transmission path comprising:
a notch filter having an input connected to the upstream signal;
an upconverter connected to the notch filter; and
a transmitter switch connected to an output of the upconverter;
a control path comprising:
a band pass filter having an input connected to the upstream signal; and
a detector and demodulator unit connected to the band pass filter;
wherein the detector and demodulator unit outputs a control signal to control the upconverter and the transmitter switch based on a pre-preamble signal received from the wireless modem unit.
2. A transverter control system for a wireless modem, the system comprising:
a wireless modem unit (WMU) comprising:
a processor;
a modulator controlled by the processor;
a pre-preamble modulator controlled by the processor;
a summation circuit connected to receive an output from the modulator and an output from the pre-preamble modulator; and
an output stage connected to an output of the summation circuit;
wherein a pre-preamble signal generated-by the pre-preamble modulator alerts the output stage of an impending data burst; and
a transverter control system comprising:
a diplexer connected to a wireless modem unit (WMU) and receiving a downstream signal and outputting an upstream signal;
a transmission path comprising:
a notch filter having an input connected to the upstream signal;
an upconverter connected to the notch filter; and
a transmitter switch connected to an output of the upconverter;
a control path comprising:
a band pass filter having an input connected to the upstream signal; and
a detector and demodulator unit connected to the band pass filter;
wherein the detector and demodulator unit outputs a control signal to control the upconverter and the transmitter switch based on a pre-preamble signal received from the wireless modem unit.
3. A method of control of a transverter in a wireless access system, the method comprising:
creating a pre-preamble signal and a control data signal in a wireless modem unit (WMU);
transmitting the pre-preamble signal as a notification signal;
transmitting the control data signal to the transverter;
detecting the pre-preamble signal at the transverter, and in response to the detected signal, disabling a transmitter switch;
decoding and processing the control data signal; and
resetting the transmitter switch.
4. The transverter control system according to claim 1 , wherein:
the wireless modem unit (WMU) comprises,
a processor;
a modulator controlled by the processor,
a pre-preamble modulator controlled by the processor,
a summation circuit connected to receive an output from the modulator and an output from the pre-preamble modulator, and
an output stage connected to an output of the summation circuit;
wherein a pre-preamble signal generated by the pre-preamble modulator alerts the output stage of an impending data burst.
5. The transverter control system according to claim 1 , wherein the WMU comprises a pre-preamble modulator configured to produce a carrier at a frequency outside of a normal data band.
6. The transverter control system according to claim 5 , wherein the carrier is Amplitude Shift Key modulated.
7. The transverter control system according to claim 6 , wherein the diplexer is connected at an output stage of the, wireless modem unit (WMU).
8. The transverter control system according to claim 7 , wherein the Wireless Modem Unit (WMU) is part of a wireless broadband access system.
9. The transverter control system according to claim 1 , wherein the Wireless Modem Unit (WMU) is part of a wireless broadband access system.
10. The transverter control system according to claim 2 , wherein the Wireless Modem Unit (WMU) is part of a wireless broadband access system.
11. The transverter control system according to claim 3 , wherein the Wireless Modem Unit (WMU) is part of a wireless broadband access system.
12. The transverter control system according to claim 7 , wherein the impending data burst is a Data Over Cable Service Interface Specification (DOCSIS) formatted message in a broadband wireless access system.
13. The transverter control system according to claim 1 , wherein the upstream and downstream signals facilitate a Data Over Cable Service Interface Specification (DOCSIS) formatted message in a broadband wireless access system.
14. The transverter control system according to claim 2 , wherein the impending data burst is a Data Over Cable Service Interface Specification (DOCSIS) formatted message in a broadband wireless access system.
15. The transverter control system according to claim 3 , wherein the preamble and control signals facilitate a Data Over Cable Service Interface Specification (DOCSIS) formatted message in a broadband wireless access system.