Methods and apparatus for canceling co-channel interference in a receiving system using spatio-temporal whitening

A method of synchronizing a receiver with a received signal, the method comprising:

• decimating a portion of the received signal to produce a first group of samples for the portion of the received signal;
• selecting a plurality of signal samples from the first group of samples based on an initial timing estimate made without spatio-temporal whitening to produce the plurality of signal samples for a portion of the received signal;
• applying spatio-temporal interference whitening to each of the plurality of signal samples to produce a plurality of whitened signal samples;
• determining a best whitened signal sample from among the plurality of whitened signal samples based on channel estimates and on a relative, minimum value of a specified metric for each of the plurality of whitened signal samples;
• and
• synchronizing the receiver based on timing of the best whitened signal sample.

A method of synchronizing a receiver with a received signal, the method comprising:

• decimating a portion of the received signal to produce a plurality of signal samples;
• estimating a timing for the received signal based on the plurality of signal samples and on channel estimates without applying spatio-temporal whitening to the plurality of signal samples;
• determining if a signal-to-noise ratio of the received signal, received using the timing is below a specified threshold value;
• applying spatio-temporal interference whitening to each of the plurality of signal samples to produce a plurality of whitened signal samples, if the signal-to-noise ratio is below the specified threshold value;
• determining a best whitened signal sample from among the plurality of whitened signal samples bused on channel estimates and on a relative, minimum value of a specified metric for each of the plurality of whitened signal samples, if the signal-to-noise ratio is below the specified threshold value;
• and
• synchronizing the receiver based on timing of the best whitened signal sample if the signal-to-noise ratio is below the specified threshold value.

Apparatus for synchronizing a receiver with a received signal, the apparatus comprising:

• means for decimating a portion of the received signal to produce a plurality of signal samples;
• means for estimating a timing for the received signal based on the plurality of signal samples and on channel estimates without applying spatio-temporal whitening to the plurality of signal samples;
• means for determining if a signal-to-noise ratio of the received signal, received using the timing is below a specified threshold value;
• means for applying spatio-temporal interference whitening to each of the plurality of signal samples to produce a plurality of whitened signal samples;
• means for determining a best whitened signal sample from among the plurality of whitened signal samples based on channel estimates and on a relative, minimum value of a specified metric for each of the plurality of whitened signal samples;
• and
• means for synchronizing the receiver based on timing of the best whitened signal sample.

A processor-controlled receiving system enabled to cancel interference in a received signal, the receiving system comprising:

• synchronization and channel estimation logic;
• a first single antenna interference rejection (SAIR) block connected to the synchronization and channel estimation logic, the SAIR block for determining channel parameters and applying a whitening filter to the received signal based on a frequency offset between a desired signal and an interferer to obtain a whitened signal;
• demodulation logic for demodulating the whitened signal using the channel parameters;
• and
• a second SAIR block connected to the demodulation logic, the second SAIR block for updating the whitening filter parameters and the channel parameters based on each selected portion of a plurality of portions of a timeslot in the received signal.

A processor-controlled receiving system comprising:

• demodulation logic;
• and
• a interference whitening synchronization block preceding the demodulation logic, the interference whitening synchronization block disposed to receive a received signal and further comprising:
• a decimator disposed to receive the received signal, the decimator for producing a plurality of signal samples from the received signal;
• a timing selector operatively connected to the decimator;
• a spatio-temporal interference whitening (STIW) block connected to the decimator, the STIW block for applying spatio-temporal interference whitening to each of the plurality of signal samples to produce a plurality of whitened signal samples;
• and
• a selection subsystem connected to the timing selector and the STIW block, the selection subsystem operable to determine a best whitened signal sample from among the plurality of whitened signal samples based on channel estimates and on a relative, minimum value of a specified metric and for synchronizing the receiver with the received signal based on timing of the best whitened signal sample.

A processor-controlled receiving system comprising:

• demodulation logic;
• and
• a interference whitening synchronization block preceding the demodulation logic, the interference whitening synchronization block disposed to receive a received signal and further comprising:
• synchronization and channel estimation logic for producing a plurality of signal samples from the received signal;
• a comparator and selector block connected to the synchronization and channel limitation logic;
• a spatio-temporal interference whitening (STIW) block connected to the comparator and selector block, the STIW block for applying spatio-temporal interference whitening to each of the plurality of signal samples to produce a plurality of whitened signal samples;
• and
• a selection subsystem connected to a timing selector and the STIW block, the selection subsystem operable to determine a best whitened signal sample from among the plurality of whitened signal samples based on channel estimates and on a relative, minimum value of a specified metric and for synchronizing the receiver with the received signal based on timing of the best whitened signal sample.