M-Ary Orthogonal Keying under Carrier Frequency Offset

Nozomu NISHINAGA  Yoshihiro IWADARE  

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E79-A   No.9   pp.1408-1414
Publication Date: 1996/09/25
Online ISSN: 
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on Information Theory and Its Applications)
Category: Communication/Spread Spectrum
M-ary orthogonal keying,  carrier frequency offset,  spurious signal component,  correlation detection,  Walsh function sets,  circulant Hadamard matrix,  

Full Text: PDF(556.3KB)>>
Buy this Article

M-ary orthogonal keying (MOK) systems under carrier frequency offset (CFO) are investigated. It is shown that spurious signals are introduced by the offset frequency components of spectrum after multiplication in correlation detection process, and some conditions on robust orthogonal signal sets are derived. Walsh function sets are found to be very weak against CFO, since they produce large spurious signals. As robust orthogonal signal sets against CFO, the rows of circulant Hadamard matrices are proposed and their error performanses are evaluated. The results show that they are good M-ary orthogonal signal sets in the presence of CFO.