Abstract
The effects of frequency offsets and aperiodic random spreading sequences on the performance of asynchronous multicarrier code division multiple access (CDMA) systems with correlated fading are investigated in this research. Random parameters including asynchronous delays, correlated Rayleigh fading and spreading sequences are averaged to determine the covariance matrix of the interference-plus-noise vector. An analytic expression for the average signal-to-interference-plus-noise ratio (SINK) is obtained. Furthermore, average bit error probability (BEP) based on the Gaussian approximation is also derived. We show that the system degrades significantly if the frequency offset of the desired user is present, while the system is insensitive to interferers' frequency offsets. In consequence, it is crucial to estimate and compensate the desired user's synchronization imperfection. Finally, design tradeoff among the number of sub-carriers, fading correlations, and inter-carrier interference (ICI) are presented in simulation results.
| Original language | English |
|---|---|
| Article number | 01 |
| Pages (from-to) | 9-20 |
| Number of pages | 12 |
| Journal | Proceedings of SPIE - The International Society for Optical Engineering |
| Volume | 5440 |
| DOIs | |
| State | Published - 1 Dec 2004 |
| Event | Digital Wireless Communications VI - Orlando, FL, United States Duration: 12 Apr 2004 → 13 Apr 2004 |
Keywords
- Carrier frequency offset
- Code division multiple access (CDMA)
- Direct sequence-CDMA (DS-CDMA)
- Inter-carrier interference (ICI)
- Multicarrier-direct sequence-CDMA (MC-DS-CDMA)