Title :
Spectral correlation of AMPS signals and its application to interference rejection
Author :
He, Rong ; Reed, Jeffrey H.
Author_Institution :
Mobile & Portable Radio Res. Group, Virginia Polytech. Inst. & State Univ., Blacksburg, VA, USA
Abstract :
AMPS interference cancellation is demonstrated using a blind adaptive filter that exploits the cyclostationary characteristics of the AMPS signal produced by a SAT (supervisory audio tone). Theoretical analysis of the cyclostationary characteristics of an AMPS signal is included. A time-dependent adaptive filter (TDAF), which could be implemented as a FRESH filter, is developed that exploits the spectral correlation of the received signal. This algorithm is tested using both simulated and digitized AMPS signals. Results show that there is 20-30 dB improvement of the demodulated voice SNR for severely corrupted signals
Keywords :
adaptive filters; cochannel interference; correlation methods; digital filters; frequency modulation; interference suppression; spectral analysis; AMPS signals; FRESH filter; blind adaptive filter; cyclostationary characteristics; demodulated voice SNR; interference rejection; narrow band FM signal; spectral correlation; supervisory audio tone; time-dependent adaptive filter; Adaptive filters; Frequency modulation; Helium; IIR filters; Interference cancellation; Narrowband; Phase locked loops; Signal analysis; Telephony; Testing;
Conference_Titel :
Military Communications Conference, 1994. MILCOM '94. Conference Record, 1994 IEEE
Conference_Location :
Fort Monmouth, NJ
Print_ISBN :
0-7803-1828-5
DOI :
10.1109/MILCOM.1994.473963
