Patent ID: 8548086

Claim:
A signal detection method by a wireless device comprising multiple receivers, each receiver coupled to an antenna and configured to receive a signal from a same transmitting device via a propagation channel, the method comprising: selecting a plurality of the received signals from said multiple receivers; transforming the selected signals into frequency-domain signals; shifting each of the frequency-domain signals in phase by a negative value of a respective reference phase; combining the phase-shifted signals into one signal, wherein the combined signal is represented by {S(n l )} l=1 L ; circularly shifting the combined signal by m subcarrier spacings in accordance with S m ⁡ ( n l ) = { S ⁡ ( n l + m ) if ⁢ ⁢ n l ≤ L 2 - m S ⁡ ( L 2 - n l - m ) if ⁢ ⁢ n l > L 2 - m , wherein m is an integer; multiplying the circularly shifted signal with a signal stored in a storage in the device to generate a signal product; transforming the signal product into a time-domain signal; and performing peak detection on the time-domain signal.