Multi-Band Wavelet-Packet Spreading Codes with Intra-Code Subband Diversity for Communications in Multipath Fading Channels

摘要

Mobile communication channels always suffer serious frequency-selective fading due to multipath effect. Tra- ditional spreading codes are characterized by the fact that their time-domain orthogonality is based on fixed chip width across a code period. They often fail to perform well under frequency- selective fading. This paper proposes a new class of CDMA codes, wavelet-packet orthogonal codes capable to retain time- domain orthogonality as well as to offer intra-code subband di- versotu to mitigate frequency-selective fading.