US 7,583,758 B2Granted

Carrier detection applicable for SISO, MIMO, MISO, and SIMO communications

AssigneeBroadcom Corporation

InventorsRohit V. Gaikwad, Rajendra Tushar Moorti, Jason A. Trachewsky

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Abstract

Carrier detection applicable for SISO, MIMO, MISO, and SIMO communications. A novel approach is presented to perform carrier detection for a signal found in any of a wide variety of communication systems including single-input-multiple-output (SISO), multiple-input-multiple-output (MIMO), multiple-input-single-output (MISO) single-input-multiple-output (SISO), communication systems. This novel approach to performing carrier detection is more robust than those approaches existent in the art. By employing normalization with respect to power in determining a modified correlation function, there is less susceptibility to false detects. Also, this approach is quite robust to any circuitry DC offsets that may undesirably exist within a communication device that undergoes operational changes due to a variety of factors including environmental perturbations and/or changes in processing circuitry within the communication device (e.g., changes in gain control).

Claims26

Dependent claims

An apparatus, comprising:

an auto-correlation detection module that is operable to:
calculate a modified correlation function that varies as a function of each sample of a first plurality of samples of a first moving window and each sample of a second plurality of samples of a second moving window of an OFDM (Orthogonal Frequency Division Multiplexing) packet, wherein the modified correlation function is normalized with respect to a first power corresponding to the first moving window and a second power corresponding to the second moving window;
compare the modified correlation function to a modified correlation function threshold;
compare the first power corresponding to the first moving window to a first power threshold;
and
compare the second power corresponding to the second moving window to a second power threshold;
and
a match filter detection module that is operable to:
calculate a match filter function that varies as a function of each sample of the first plurality of samples of the first moving window and each sample of the second plurality of samples of the second moving window of the OFDM packet as compared to a predetermined plurality of samples;
identify a first peak in the match filter function by comparing the match filter function to a first match filter function threshold;
identify a second peak in the match filter function by comparing the match filter function to a second match filter function threshold;
identify a difference in magnitude between the first peak and the second peak;
identify whether the match filter function falls below a third match filter function threshold between the first peak and the second peak;
identify a predetermined number of peaks in the match filter function after the first peak and the second peak;
compare the first power corresponding to the first moving window to a third power threshold;
and
compare the second power corresponding to the second moving window to a fourth power threshold;
and
a combining module that is operable to:
receive a first output signal from the auto-correlation detection module;
receive a second output signal from the match filter detection module;
and
process the first output signal and the second output signal to generate a carrier detect signal.

20 more elements

An apparatus, comprising:

a first auto-correlation detection module that is operable to generate a first carrier detect signal corresponding to correlation of a first moving window and a second moving window of an OFDM (Orthogonal Frequency Division Multiplexing) packet as determined using a first plurality of correlation parameters;
a match filter detection module that is operable to generate a match filter detection signal corresponding to match filtering between at least one of the first moving window and the second moving window of the OFDM packet and a predetermined window as determined using a plurality of match filter parameters;
a second auto-correlation detection module that is operable to generate a second carrier detect signal corresponding to correlation of the first moving window and the second moving window of the OFDM packet as determined using a second plurality of correlation parameters;
and
a combining module that is operable to process the first carrier detect signal, the match filter detection signal, and the second carrier detect signal thereby generating an output carrier detect signal.

2 more elements

A method, comprising:

calculating a modified correlation function that varies as a function of each sample of a first plurality of samples of a first moving window and each sample of a second plurality of samples of a second moving window of an OFDM (Orthogonal Frequency Division Multiplexing) packet, wherein the modified correlation function is normalized with respect to a first power corresponding to the first moving window and a second power corresponding to the second moving window;
performing a first comparison that includes comparing the modified correlation function to a modified correlation function threshold;
performing a second comparison that includes comparing the first power corresponding to the first moving window to a first power threshold;
and
employing a combining module to process results from the first comparison, the second comparison, and the third comparison thereby generating a carrier detect signal corresponding to a received signal stream.

2 more elements

Dependencies are inferred from the claim text.