Preamble detection with multiple receive antennas
First Claim
1. A system, comprising:
- a correlation module that receives modulated signals from R antennas, that correlates each of said modulated signals with Y preamble sequences, and that generates Y correlation values for each of said R antennas, where R and Y are integers greater than 1, wherein said modulated signals include sub-carriers modulated using orthogonal frequency domain multiplexing (OFDM); and
a control module that generates correlation sums by adding each of said Y correlation values for one of said R antennas to corresponding ones of said Y correlation values for others of said R antennas, that selects a largest correlation sum from said correlation sums, and that detects one of said Y preamble sequences in said modulated signals when a magnitude of said largest correlation sum is greater than or equal to a first predetermined threshold,wherein said control module divides N of said sub-carriers into L bands when a channel gain of said sub-carriers is not substantially the same for all of said sub-carriers, where N and L are integers greater than 1, and where each of said L bands includes N/L of said sub-carriers, andwherein said correlation module correlates symbols in every Pth one of said N/L sub-carriers in each of said L bands with corresponding symbols in each of said Y preamble sequences and generates intra-band correlation values for each band for each of said Y preamble sequences.
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Accused Products
Abstract
A system comprises a correlation module that receives modulated signals from R antennas, that correlates each of the modulated signals with Y preamble sequences, and that generates Y correlation values for each of the R antennas, where R and Y are integers greater than or equal to 1. A control module generates correlation sums by adding each of the Y correlation values for one of the R antennas to corresponding ones of the Y correlation values for others of the R antennas, that selects a largest correlation sum from the correlation sums, and that detects one of the preamble sequences in the modulated signals when a magnitude of the largest correlation sum is greater than or equal to a first predetermined threshold.
38 Citations
26 Claims
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1. A system, comprising:
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a correlation module that receives modulated signals from R antennas, that correlates each of said modulated signals with Y preamble sequences, and that generates Y correlation values for each of said R antennas, where R and Y are integers greater than 1, wherein said modulated signals include sub-carriers modulated using orthogonal frequency domain multiplexing (OFDM); and a control module that generates correlation sums by adding each of said Y correlation values for one of said R antennas to corresponding ones of said Y correlation values for others of said R antennas, that selects a largest correlation sum from said correlation sums, and that detects one of said Y preamble sequences in said modulated signals when a magnitude of said largest correlation sum is greater than or equal to a first predetermined threshold, wherein said control module divides N of said sub-carriers into L bands when a channel gain of said sub-carriers is not substantially the same for all of said sub-carriers, where N and L are integers greater than 1, and where each of said L bands includes N/L of said sub-carriers, and wherein said correlation module correlates symbols in every Pth one of said N/L sub-carriers in each of said L bands with corresponding symbols in each of said Y preamble sequences and generates intra-band correlation values for each band for each of said Y preamble sequences. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method, comprising:
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receiving modulated signals from R antennas, where R is an integer greater than 1, wherein said modulated signals include sub-carriers modulated using orthogonal frequency domain multiplexing (OFDM); correlating each of said modulated signals with Y preamble sequences, where Y is an integer greater than 1; generating Y correlation values for each of said R antennas; generating correlation sums by adding each of said Y correlation values for one of said R antennas to corresponding ones of said Y correlation values for others of said R antennas; selecting a largest correlation sum from said correlation sums; detecting one of said Y preamble sequences in said modulated signals when a magnitude of said largest correlation sum is greater than or equal to a first predetermined threshold; dividing N of said sub-carriers into L bands when a channel gain of said sub-carriers is not substantially the same for all of said sub-carriers, where N and L are integers greater than 1, and where each of said L bands includes N/L of said sub-carriers; and correlating symbols in every Pth one of said N/L sub-carriers in each of said L bands with corresponding symbols in each of said Y preamble sequences and generating intra-band correlation values for each band for each of said Y preamble sequences, where P is an integer greater than or equal to 1. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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Specification