Multirate Multiband Hybrid MC/MC-DS CDMA for Ultra Wideband Transmission
Date Issued
2004
Date
2004
Author(s)
Shen, Juei-Chin
DOI
en-US
Abstract
Ultra wideband (UWB) transmission is adopted in the specific of 802.15 3a for wireless personal area network (WPAN) and applied to multimedia communications. The requirement of high and multiple data rates motivates us to consider how to plan the feasible transceiver structure on available ultra wide bandwidth. Multiband trans-mission technology, which divides the available bandwidth into several conjunctional subbands and transmits information through one subband at one time, is presented here to simplify the hardware complexity and still offer enough wide subbands for multiple access schemes. The novel hybrid MC/MC-DS CDMA structure, which exploits joint time and frequency domain spreading, is constructed in each subband. In another de-signed consideration of multirate communication, we choose the known multirate ac-cess schemes – multicode access and variable spreading length access. Furthermore, we propose two kinds of multiuser detection receivers, to decorrelate and cancel MAI from the effective users of a high rate user due to multipath channel. Two possible imple-mentations, joint and separate TF-domain, are considered for each kind of proposed re-ceivers. From the simulation, we recommend adopting MCD access scheme using joint TF-domain decorrelating receiver whether increasing spreading code assignment on T-domain or F-domain and using joint TF-domain interference cancellation receiver to avoid arithmetic computations of crosscorrelation matrix of TF-domain spreading codes. Considering the issue of the complexity, which means to use separate TF-domain re-ceiver, we prefer adopting VSL access scheme whether increasing spreading code as-signment on T-domain or F-domain.
Subjects
多速率
多載波
超寬頻
ultra wideband
multicarrier
multirate
Type
thesis