Patent ID: 7280615

Claim:
A method of performing a clear channel assessment in a wireless network, comprising: listening for channel energy on a wireless channel; demodulating the channel energy into a non-synchronized in-phase component and a non-synchronized quadrature phase component; squaring the non-synchronized in-phase component; squaring the non-synchronized quadrature phase component; multiplying the non-synchronized in-phase component and the non-synchronized quadrature phase component to produce an I−Q product; subtracting the squared non-synchronized quadrature component from the squared non-synchronized in-phase component to produce a first intermediate value; doubling the I−Q product to produce a second intermediate value; adding the first intermediate value and the second intermediate value to produce a clear channel assessment input value; performing a carrier signal detection function on the clear channel assessment input value to produce a clear channel assessment output value; and using the clear channel assessment output value to determine whether a signal is present in the wireless channel.