Method and apparatus for training using variable transmit signal power levels
A method and apparatus for a multiple channel communication device training, and processing utilizing a transmit signal power control operation. Multiple channel communication devices utilize inter-channel crosstalk mitigation techniques, such as MIMO processing modules or MIMO precoding systems, to cancel unwanted crosstalk coupling across active and provisioned channels. Upon provisioning and activation of a new channel that connects to the multiple channel communication device the signal on the new channel couples into other channels and the existing MIMO filtering or processing structure is untrained to mitigate the crosstalk from the new channel. A power control training operation prevents crosstalk from hindering operation on other channels during the training operation. During one example training operation, the power level of a transmit signal is incrementally increased as the crosstalk cancellation filter(s) are trained.
1 . A method for canceling crosstalk type coupling in a multi-channel communication system comprising:
initiate signal transmission at a first power level on a channel during a training process, wherein one or more other channels associated with the multi-channel communication device are provisioned and active;
estimating one or more coupling components, on at least one of the one or more other channels;
processing the one or more the coupling components, to generate one or more filter coefficients; and
configuring one or more filters with the one or more filter coefficients, wherein transmitting at the first power level does not disrupt operation of the one or more other channels and the one or more filters are configured to generate cancellation signals to cancel the one or more coupling components.
2 . The method of claim 1 , further comprising transmitting a training signal on the channel being provisioned at a second power level, wherein the second power level is greater than the first power level and signals transmitted at the second power level are processed based on the filter coefficients.
3 . The method of claim 2 , further comprising detecting and processing one or more coupling components on at least one of the one or more channels based on the signal transmitted at the second power level and modifying at least one filter coefficient.
4 . The method of claim 1 , wherein configuring one or more filters comprises configuring at least one precoder filter or at least one receiver filter, or both.
5 . The method of claim 1 , wherein the method occurs at a point location within a point to multi-point communication device.
6 . A method for training a new channel in a multi-channel communication device when other channels associated with the multi-channel communication device are already provisioned and active comprising:
transmitting a training signal over the new channel at a first power level, wherein the first power level is lower than a power level used during normal communication on the channel;
processing one or more received signals received over the new channel, the already provisioned channels or both to determine one or more coupling values;
configuring one or more coupling cancellation devices with the coupling values; and
increasing the power level for subsequent transmitted signals on the new channel.
7 . The method of claim 6 , wherein the coupling cancellation devices comprise a receiver based MIMO processing module, a transmitter based precode MIMO processing module, or both.
8 . The method of claim 7 , wherein the processing module comprises one or more filters.
9 . The method of claim 6 , wherein the training signal is transmitted from a remote multi-point location to a point location and coupling information is transmitted from the remote multi-point location to the point location.
10 . The method of claim 6 , further comprising transmitting a training signal at a second power level, which is greater than the first power level.
11 . A system for training one or more filters in a multi-channel communication device when other channels associated with the multi-channel communication device are provisioned and active comprising:
a control device configured to control transmit power of a training signal;
a transmitter, responsive to the control device, configured to transmit one or more training signals at a first power level, wherein the first power level is less than a power level utilized on a provisioned channel;
a receiver configured to receive the training signal and at least one signal on a provisioned channel;
a MIMO processing module configured to:
establish one or more coefficients;
process one or more received signals utilizing the one or more coefficients to cancel unwanted coupling from the newly active channel to the provisioned channel.
12 . The system of claim 11 , wherein the MIMO processing module comprises at least one filter and at least one junction configured to combine a cancellation signal with a received signal.
13 . The system of claim 11 , wherein establishing one or more coefficients occurs when a channel, whether being provisioned or already provisioned, initiates communication.
14 . The system of claim 11 , wherein the control device is in communication with the transmitter to thereby control transmit power level.
15 . The system of claim 11 , wherein the transmitter is configured to transmit training signals at two or more different power levels, each of which is less than the power level utilized on the provisioned channels.
16 . The system of claim 11 , wherein the MIMO processing module is configured to generate cancellation signals.
17 . The system of claim 16 , wherein for each of the power levels, the MIMO processing module is configured to update the one or more coefficients.
18 . The system of claim 16 , wherein the multi-channel communication system comprises a communication system configured as a point to multi-point communication system.
19 . A system for performing MIMO processing during training of a first channel without disrupting communication on a second channel comprising:
a transmitter configured to transmit on the first channel a first training signal at a first power level and a second training signal at a second power level, wherein the first power level is less than the second power level, and transmit a second signal on the second channel;
a receiver configured to receive the first training signal on the first channel and the second signal on the second channel;
a MIMO processing module configured to cancel coupling from the first training signal and the second training signal transmitted on the first channel to the second signal on a second channel, the module comprising:
at least one linear or decision-feedback filter having one or more coefficients configured to generate at least one cancellation signal, wherein the coefficients are established in stages responsive to the different power levels of the first training signal and the second training signal; and
at least one junction configured to combine the at least one cancellation signal with the second signal to cancel coupling.
20 . The system of claim 19 , further comprising a MIMO precoding system configured to generate one or more cancellation signals.
21 . The system of claim 19 , wherein the power level of the first training signal does not disrupt operation of the second channel.
22 . The system of claim 19 , wherein the second training signal when transmitted at the power level of the second training signal does not disrupt operation due to cancellation of crosstalk by the at least one cancellation signal.