Cyclic shift delay detection using a classifier

A method in a mobile device for determining a cyclic shift delay (CSD) mode from a plurality of CSD modes, the method comprising:

• receiving an orthogonal frequency division multiplex (OFDM) signal;
• computing a channel impulse response (CIR) of the OFDM signal;
• match filtering the CIR with a first CSD mode from the plurality of CSD modes to produce a first output;
• match filtering the CIR with a second CSD mode from the plurality of CSD modes to produce a second output;
• coupling the first output and the second output to a classifier;
• and
• determining the CSD mode from a maximum of the classifier.

A method in a mobile device for determining a cyclic shift delay (CSD) mode from a plurality of CSD modes, the method comprising:

• receiving an orthogonal frequency division multiplex (OFDM) signal;
• converting I/Q samples to a channel frequency response (CFR);
• extracting a first feature in the frequency domain for a CSD mode 2 signal from the CFR to produce a first extracted frequency-domain feature;
• providing the first extracted frequency-domain feature to the classifier;
• and
• determining the CSD mode from a maximum of the classifier.

A mobile device for determining a cyclic shift delay (CSD) mode from a plurality of CSD modes, the mobile device comprising:

• a channel impulse response (CIR) unit to determine a CIR of received an orthogonal frequency division multiplex (OFDM) signal;
• a first matched filter coupled to an output of the CIR unit, the first matched filter to match filter the CIR with a first CSD mode from the plurality of CSD modes to produce a first output;
• a second matched filter coupled to the output of the CIR unit, the second matched filter to match filter the CIR with a second CSD mode from the plurality of CSD modes to produce a second output;
• and
• a comparator with inputs coupled to the first output and the second output, the comparator to determine the CSD mode from a maximum of the first output and second output.

A mobile device for determining a cyclic shift delay (CSD) mode from a plurality of CSD modes, the mobile device comprising:

• a channel impulse response (CIR) unit to determine a CIR of received an orthogonal frequency division multiplex (OFDM) signal;
• a first matched filter coupled to an output of the CIR unit, the first matched filter to match filter the CIR with a first CSD mode from the plurality of CSD modes to produce a first output;
• a second matched filter coupled to the output of the CIR unit, the second matched filter to match filter the CIR with a second CSD mode from the plurality of CSD modes to produce a second output;
• and
• a classifier with inputs coupled to the first output and the second output, the classifier to determine the CSD mode from a maximum of the first output and second output.

A mobile device for determining a cyclic shift delay (CSD) mode from a plurality of CSD modes, the mobile device comprising:

• a fast Fourier transform (FFT) unit to receive an orthogonal frequency division multiplex (OFDM) signal;
• a first frequency-domain feature extractor having an input coupled to the FFT unit and an output to produce a first frequency-domain extracted feature;
• and
• the classifier with an input coupled to the output, the classifier to determine the CSD mode from a maximum of the first output and second output.

A mobile device for determining a cyclic shift delay (CSD) mode from a plurality of CSD modes, the mobile device comprising:

• means for receiving an orthogonal frequency division multiplex (OFDM) signal;
• means for computing a channel impulse response (CIR) of the OFDM signal;
• means for match filtering the CIR with a first CSD mode from the plurality of CSD modes to produce a first output;
• means for match filtering the CIR with a second CSD mode from the plurality of CSD modes to produce a second output;
• and
• means for determining the CSD mode from a maximum of the first output and second output.

A mobile device for determining a cyclic shift delay (CSD) mode from a plurality of CSD modes, the mobile device comprising:

• means for receiving an orthogonal frequency division multiplex (OFDM) signal;
• means for computing a channel impulse response (CIR) of the OFDM signal;
• means for match filtering the CIR with a first CSD mode from the plurality of CSD modes to produce a first output;
• means for match filtering the CIR with a second CSD mode from the plurality of CSD modes to produce a second output;
• means for coupling the first output and the second output to a classifier;
• and
• means for determining the CSD mode from a maximum of the classifier.

A mobile device for determining a cyclic shift delay (CSD) mode from a plurality of CSD modes, the mobile device comprising:

• means for receiving an orthogonal frequency division multiplex (OFDM) signal;
• means for converting I/Q samples to a channel frequency response (CFR);
• means for extracting a first feature in the frequency domain for a CSD mode 2 signal from the CFR to produce a first extracted frequency-domain feature;
• means for providing the first extracted frequency-domain feature to the classifier;
• and
• means for determining the CSD mode from a maximum of the classifier.

A non-volatile computer-readable storage medium for determining a cyclic shift delay (CSD) mode from a plurality of CSD modes, the non-volatile computer-readable storage medium including program code stored thereon, the program code, when executed by a processor, comprising code for:

• receiving an orthogonal frequency division multiplex (OFDM) signal;
• computing a channel impulse response (CIR) of the OFDM signal;
• match filtering the CIR with a first CSD mode from the plurality of CSD modes to produce a first output;
• match filtering the CIR with a second CSD mode from the plurality of CSD modes to produce a second output;
• and
• determining the CSD mode from a maximum of the first output and second output.

A non-volatile computer-readable storage medium for determining a cyclic shift delay (CSD) mode from a plurality of CSD modes, the non-volatile computer-readable storage medium including program code stored thereon, the program code, when executed by a processor, comprising code for:

• receiving an orthogonal frequency division multiplex (OFDM) signal;
• computing a channel impulse response (CIR) of the OFDM signal;
• match filtering the CIR with a first CSD mode from the plurality of CSD modes to produce a first output;
• match filtering the CIR with a second CSD mode from the plurality of CSD modes to produce a second output;
• coupling the first output and the second output to a classifier;
• and
• determining the CSD mode from a maximum of the classifier.

A non-volatile computer-readable storage medium for determining a cyclic shift delay (CSD) mode from a plurality of CSD modes, the non-volatile computer-readable storage medium including program code stored thereon, the program code, when executed by a processor, comprising code for:

• receiving an orthogonal frequency division multiplex (OFDM) signal;
• converting I/Q samples to a channel frequency response (CFR);
• extracting a first feature in the frequency domain for a CSD mode 2 signal from the CFR to produce a first extracted frequency-domain feature;
• providing the first extracted frequency-domain feature to the classifier;
• and
• determining the CSD mode from a maximum of the classifier.