
{"publication_number": "US-2003072392-A1", "abstract": "a signal to noise ratio estimator and method for a received signal which includes a communication component and a noise component is disclosed . one embodiment is an in - service , blind , decision - directed estimator for a cpfsk communication signal . a preferred embodiment determines the power of a communication signal component by combining the received signal with a signal that is a delayed complex conjugate of the received signal and then removing the real component of the combined signal .", "application_number": "US-97736201-A", "description": "the invention estimates the snr of a received signal which includes a communication signal and a noise signal . the communication signal includes plural symbols comprised of one or more bits . each of the communication and noise signals may have a real and an imaginary component . notionally , the invention estimates the snr by the following equation : snr est = signal \ue89e \ue89e power est [ signal + noise \ue89e \ue89e power est - signal \ue89e \ue89e power est ] snr est = e \ue8a0 [ b ^ i \ue89e im \ue8a0 ( r i \ue8a0 ( k ) \ue89e r i * \ue8a0 ( k - \u03c4 ) ) ] \uf603 e \ue8a0 [ r i \ue8a0 ( k ) \ue89e r i * \ue8a0 ( k ) ] - e \ue8a0 [ b ^ i \ue89e im \ue8a0 ( r i \ue8a0 ( k ) \ue89e r i * \ue8a0 ( k - \u03c4 ) ) ] \uf604 r i ( k ) is the k th sample of the complex baseband received signal ; { circumflex over ( b )