Title :
A novel AFC scheme for Walsh-Hadamard code division multiplexing
Author :
Kojima, T. ; Suzuki, A.
Author_Institution :
Grad. Sch. of Inf. & Eng., Univ. of Electro-Commun., Chofu, Japan
Abstract :
In this paper, we propose a novel automatic frequency control (AFC) scheme for code division multiplexing (CDM) system employing Walsh code. The proposed AFC scheme discriminates the frequency shift of the received signal by detecting the signal energy after Walsh-Hadamard transform (WHT). The configuration of the proposed AFC scheme is analogous with that of delay locked loop (DLL) for direct-sequence spread-spectrum (DS-SS) communications. The initial acquisition performance of the proposed AFC scheme is evaluated by computer simulation. It is confirmed that the proposed AFC scheme achieves fast acquisition when the multiplexing factor is less than WHT order.
Keywords :
Hadamard transforms; Walsh functions; automatic frequency control; code division multiplexing; delay lock loops; spread spectrum communication; AFC scheme; CDM system; DLL; DS-SS communications; WHT; Walsh code; Walsh-Hadamard code division multiplexing; Walsh-Hadamard transform; automatic frequency control scheme; code division multiplexing system; delay locked loop; direct-sequence spread-spectrum communications; frequency shift; signal energy; Frequency control; Frequency division multiplexing; Frequency modulation; Helicopters; OFDM; Satellite communication;
Conference_Titel :
Advanced Technologies for Communications (ATC), 2013 International Conference on
Conference_Location :
Ho Chi Minh City
Print_ISBN :
978-1-4799-1086-1
DOI :
10.1109/ATC.2013.6698120
