Patent ID: 8218692
Filing Date: 2012-07-10
Classification: H04L

Abstract:
1. A method for separating uncoordinated co-channel signals of comparable power from a single received signal impaired by one or more of intersymbol interference, mutual interference, and additive noise comprising the steps of: implementing an initial channel estimator, a blind maximum likelihood symbol detector, and a least squares channel estimator in one or more digital processors; converting the received signal in an analog to digital converter, the sample rate of the converter exceeding a symbol rate by a factor greater than or equal to two; utilizing the initial channel estimator to make an initial set of channel estimates from the converted received signal; producing a data block by decimating the converted received signal; detecting symbols from the data block in a multi-signal trellis of the blind maximum likelihood symbol detector using the most recent set of channel estimates; utilizing the least squares channel estimator to make another set of channel estimates from the detected symbols; returning to the detecting step if the channel estimates have not converged; comparing trellis end survivor's metrics to determine if the detected symbols should be accepted; returning to the first utilizing step and revising the initial channel state information if the detected symbols are not accepted; and, accepting the detected symbols and returning to the producing step if data remains.