Adaptive threshold selection system and method for detection of a signal in the presence of interference
First Claim
1. A system for enabling a node, adapted for use in a wireless communications network, to detect a data signal in a received signal noise, said system comprising:
- a first correlation circuit, adapted to correlate said received signal with a first reference sequence, and output an intermediate correlated signal;
a second correlation circuit, adapted to correlate said intermediate correlated signal with a second reference sequence, and output a correlated signal;
a threshold generating circuit, adapted to generate a threshold value based on an estimation of the variance of said intermediate correlated signal over time; and
a comparison circuit, adapted to compare said correlated signal to said threshold value to determine whether said received signal includes said data signal.
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Accused Products
Abstract
A system and method for providing adaptive threshold selection for detecting a signal in the presence of interference or noise. The system and method thus enables a node, such as a mobile user terminal, in an ad-hoc communications network to reduce the number of false alarms it experiences in the detection of communications signals due to, for example, sudden noise bursts or reception of a high powered signal that overloads the automatic gain control (AGC) device of the receiver in the node. The system and method employ two correlation circuits which correlate the received signal with two reference sequences and output a correlated signal, a threshold generating circuit which generates a threshold value based on the estimation of the variance of the output of the first correlation circuit, and a comparison circuit which compares the correlated signal to the threshold value to determine whether the received signal includes a valid data signal, as opposed to only noise.
124 Citations
10 Claims
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1. A system for enabling a node, adapted for use in a wireless communications network, to detect a data signal in a received signal noise, said system comprising:
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a first correlation circuit, adapted to correlate said received signal with a first reference sequence, and output an intermediate correlated signal; a second correlation circuit, adapted to correlate said intermediate correlated signal with a second reference sequence, and output a correlated signal; a threshold generating circuit, adapted to generate a threshold value based on an estimation of the variance of said intermediate correlated signal over time; and a comparison circuit, adapted to compare said correlated signal to said threshold value to determine whether said received signal includes said data signal. - View Dependent Claims (2, 3, 4, 9)
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5. A method for enabling a node, adapted for use in a wireless communications network, to detect a data signal in a received signal containing noise, said method comprising:
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performing a first correlation operation to correlate said received signal with a first reference sequence, and output an intermediate correlated signal; performing a second correlation operation to correlate said intermediate correlated signal with a second reference sequence, and output a correlated signal; generating a threshold value based on an estimate of the variance of said intermediate correlated signal over time; and comparing said correlated signal to said threshold value to determine whether said received signal includes said data signal. - View Dependent Claims (6, 7, 8, 10)
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Specification