TY - GEN
T1 - Walsh-like nonlinear phase orthogonal transforms for CDMA communications
AU - Poluri, Radha
AU - Akansu, Ali N.
PY - 2006
Y1 - 2006
N2 - Historically Walsh codes and Gold codes have been used as spread spectrum codes in CDMA communications. Popularity of these codes is more from the ease of generation from standard kernels rather than the efficiency of the codes. Availability of these codes is limited in number and in their lengths. By relaxing the restrictions like zero crossings, linear phase etc on the nature of codes, number of new sets of codes can be generated. In this paper, methodology has been proposed for generating new Walsh-like family codes that can be used for both synchronous and asynchronous communications. Performance characteristics of these codes have been studied in AWGN and in Rayleigh fading channels. These codes outperform Walsh codes in their asynchronous channel behavior and closely match with Gold codes performance. In addition, we present in this paper that there are a good number of such desirable code sets available in the binary sample space with different transform sizes. These new binary sets with good performance and flexible code lengths might help us to improve the spread spectrum capabilities of future CDMA communications systems.
AB - Historically Walsh codes and Gold codes have been used as spread spectrum codes in CDMA communications. Popularity of these codes is more from the ease of generation from standard kernels rather than the efficiency of the codes. Availability of these codes is limited in number and in their lengths. By relaxing the restrictions like zero crossings, linear phase etc on the nature of codes, number of new sets of codes can be generated. In this paper, methodology has been proposed for generating new Walsh-like family codes that can be used for both synchronous and asynchronous communications. Performance characteristics of these codes have been studied in AWGN and in Rayleigh fading channels. These codes outperform Walsh codes in their asynchronous channel behavior and closely match with Gold codes performance. In addition, we present in this paper that there are a good number of such desirable code sets available in the binary sample space with different transform sizes. These new binary sets with good performance and flexible code lengths might help us to improve the spread spectrum capabilities of future CDMA communications systems.
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U2 - 10.1109/ACSSC.2006.355162
DO - 10.1109/ACSSC.2006.355162
M3 - Conference contribution
AN - SCOPUS:47049118220
SN - 1424407850
SN - 9781424407859
T3 - Conference Record - Asilomar Conference on Signals, Systems and Computers
SP - 2214
EP - 2218
BT - Conference Record of the 40th Asilomar Conference on Signals, Systems and Computers, ACSSC '06
T2 - 40th Asilomar Conference on Signals, Systems, and Computers, ACSSC '06
Y2 - 29 October 2006 through 1 November 2006
ER -