MMSE-DFE equalization with antenna diversity for mobile DTV

A method of controlling a decision feedback equalizer having a feedback filter and K feed forward filter branches, wherein each of the K feed forward filter branches receives an input signal from a corresponding one of a plurality of channels associated with a corresponding one of a plurality of antennas, wherein K>1, wherein each of the K feed forward filter branches provides an output, the method comprising:

• determining an instantaneous SNR level γk for each of the K feed forward filter branches;
• comparing the instantaneous SNR level γk for each of the K feed forward filter branches to an upper threshold TH and to a lower threshold TL;
• selectively adding the outputs from the K feed forward filter branches dependent upon the comparing of the instantaneous SNR level γk for each of the K feed forward filter branches to the upper threshold TH and to the lower threshold TL;
• wherein the selectively adding of the outputs from the K feed forward filter branches comprises determining whether each of the K feed forward filter branches is in a normal state or in a recovery state, wherein each of the K feed forward filter branches is in the recovery state when the instantaneous SNR level γk for that feed forward filter branch is below the upper threshold TH, and wherein each of the K feed forward filter branches is in the normal state when the instantaneous SNR level γk for that feed forward filter branch is above the upper threshold TH,
• wherein the selectively adding of the outputs from the K feed forward filter branches further comprises transitioning at least one of the K feed forward filter branches from not being selectively added to being selectively added when either (i) the instantaneous SNR level γk for the one feed forward filter branch is above the lower threshold TL and the one feed forward filter branch is in the recovery state or (ii) the instantaneous SNR level γk for the one feed forward filter branch is greater than the upper threshold TH, and
• wherein the selectively adding of the outputs from the K feed forward filter branches further comprises transitioning at least one of the K feed forward filter branches from not being selectively added to being selectively added when all others of the K feed forward filter branches are not being selectively summed and the instantaneous SNR level γk for the one feed forward filter branch is above the instantaneous SNR levels γk for all of the other feed forward filter branches.

A method of controlling a decision feedback equalizer having a feedback filter and K feed forward filter branches, wherein each of the K feed forward filter branches receives an input signal from a corresponding one of a plurality of channels associated with a corresponding one of a plurality of antennas, wherein K>1, wherein each of the K feed forward filter branches provides an output, the method comprising:

• determining an instantaneous SNR level γk for each of the K feed forward filter branches;
• comparing the instantaneous SNR level γk for each of the K feed forward filter branches to an upper threshold TH and to a lower threshold TL;
• and,
• selectively adding the outputs from the K feed forward filter branches dependent upon the comparing of the instantaneous SNR level γk for each of the K feed forward filter branches to the upper threshold TH and to the lower threshold TL;
• wherein the selectively adding of the outputs from the K feed forward filter branches comprises:
• not adding the output of a first of the K feed forward filter branches if the instantaneous SNR level γk associated with the first of the K feed forward filter branches is less than the lower threshold TL;
• and,
• adding the output of a second of the K feed forward filter branches if the instantaneous SNR level γk associated with the second of the K feed forward filter branches is greater than the lower threshold TL, wherein the adding of the output of a second of the K feed forward filter branches includes applying a weight wk to the output of the second of the K feed forward filter branches, wherein the weight wk is determined in accordance with the instantaneous SNR level γk associated with the second of the K feed forward filter branches.