Module to module signaling with jitter modulation
View Patent ↗A method and apparatus is disclosed for incorporating secondary data for transmission as part of or concurrently with network data. In one embodiment, the secondary data comprises communication system data for use in controlling or monitoring a communication system. In one example embodiment, the secondary data is utilized to control the transmit timing of the network data to thereby jitter modulate the secondary data into the transmission of the network data. By monitoring the timing variation, or jitter, of the received network data signal, the secondary data may be recovered. In one embodiment, the secondary data is encoded to reduce the amount of time variation, i.e., jitter, that occurs when transmitting the network data. Decoding may occur upon reception of the time adjusted network data signal. In one embodiment, the encoding comprises CDMA type encoding utilizing one or more orthogonal codes.
1. A system for jitter modulating secondary data onto the transmission of network data, the system comprising:
a phase lock loop circuit comprising:
a phase detector configured to receive a clock signal and a feedback signal;
a filter configured to filter the output of the phase detector to create a filtered signal;
a junction configured to combine secondary data with the filtered signal to create a combined signal wherein the secondary data comprises system data that controls at least one aspect of operation of a remote communication device;
voltage controlled oscillator configured to generate a timing signal based on the voltage of the combined signal, the timing signal for use in controlling the timing of network data transmission;
a transmitter configured to transmit network data over a network communication channel, the timing of which is based on the combined signal, wherein the timing of the network data indicates the secondary data; and
an encoder configured to encode the secondary data, wherein the encoder utilizes an orthogonal code.
2. The system of claim 1 , wherein the timing of transmission of the network data represents the secondary data.
3. The system of claim 1 , further comprising a frequency control module configured to modify a feedback signal from the voltage controlled oscillator to the phase detector.
4. A method for recovering secondary data from network data having secondary data jitter modulated thereon after reception of the network data at a receiving communication device, the method comprising:
receiving an input signal comprising network data that has been jitter modulated to contain secondary data;
processing the input signal with a phase detector to recover the network data;
generating a loop signal as part of phase detector operation;
filtering the loop signal to generate a filtered loop signal; and
processing the filtered loop signal with the voltage detector to recover the secondary data, wherein processing the filtered loop signal comprises decoding the filtered loop signal to obtain the secondary data, wherein processing the filtered loop signal comprises detecting the changes in voltage in the filtered loop signal to determine the secondary data.
5. The method of claim 4 , wherein the changes in voltage correspond to low frequency jitter.
6. The method of claim 4 , wherein the decoding comprises multiplication of the filtered loop signal with a spreading code.
7. A method for recovering secondary data from network data having secondary data jitter modulated thereon after reception of the network data at a receiving communication device, the method comprising:
receiving an input signal comprising network data that has been jitter modulated to contain secondary data;
processing the input signal with a phase detector to recover the network data;
generating a loop signal as part of phase detector operation;
filtering the loop signal to generate a filtered loop signal; and
processing the filtered loop signal with the voltage detector to recover the secondary data, wherein processing the filtered loop signal comprises decoding the filtered loop signal to obtain the secondary data, wherein the decoding comprises multiplication of the filtered loop signal with a spreading code.
8. The method of claim 7 , wherein processing the filtered loop signal comprises detecting the changes in voltage in the filtered loop signal to determine the secondary data.
9. The method of claim 8 , wherein the changes in voltage correspond to low frequency jitter.