Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Institution
- Publication Type
Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
A Heuristic Scheduling Scheme In Multiuser Ofdma Networks, Zheng Sun, Zhiqiang He, Ruochen Wang, Kai Niu
A Heuristic Scheduling Scheme In Multiuser Ofdma Networks, Zheng Sun, Zhiqiang He, Ruochen Wang, Kai Niu
Zheng Sun
Conventional heterogeneous-traffic scheduling schemes utilize zero-delay constraint for real-time services, which aims to minimize the average packet delay among real-time users. However, in light or moderate load networks this strategy is unnecessary and leads to low data throughput for non-real-time users. In this paper, we propose a heuristic scheduling scheme to solve this problem. The scheme measures and assigns scheduling priorities to both real-time and non-real-time users, and schedules the radio resources for the two user classes simultaneously. Simulation results show that the proposed scheme efficiently handles the heterogeneous-traffic scheduling with diverse QoS requirements and alleviates the unfairness between real-time …
Multipath Diversity Of Precoded Ofdm With Linear Equalization, Xiaojing Huang
Multipath Diversity Of Precoded Ofdm With Linear Equalization, Xiaojing Huang
Faculty of Informatics - Papers (Archive)
This paper settles a controversy over the multipath diversity performance of the precoded orthogonal frequency division multiplexing system with the linear equalization. Through the asymptotical analysis of the bit error rates with extreme system parameters, a comprehensive understanding of the linear equalization's behavior in the frequency-selective multipath fading channels is gained. Compared with the optimum maximum-likelihood detection, the diversity performance of the linear equalization can be well described by an asymptotical signal-to-noise ratio (SNR) degradation, which reveals that the linear equalization can achieve the maximum multipath diversity within an operational SNR range but will lose diversity advantage as SNR increases.
On The Use Of Quasi-Orthogonal Space-Time-Frequency Codes In Mb-Ofdm Uwb, Le Chung Tran, Alfred Mertins
On The Use Of Quasi-Orthogonal Space-Time-Frequency Codes In Mb-Ofdm Uwb, Le Chung Tran, Alfred Mertins
Faculty of Informatics - Papers (Archive)
Space-Time-Frequency Codes (STFCs), which haverecently been proposed in the literature for Multiband OFDMUltra-Wideband (MB-OFDM UWB) systems to improve thesystem capacity, error performance and wireless communicationrange, are all constructed based on orthogonal structures. Thispaper examines the application of Quasi-Orthogonal STFCs(QOSTFCs) to enhance further either data rate or error performancein the recently proposed STFC MB-OFDM UWB systems.It will be shown that QOSTFCs can provide significantly bettererror performance, compared to the conventional MB-OFDMUWB (without STFCs) as well as to the Orthogonal STFCs(OSTFCs) of the same order, at the same data rate, withoutincreasing the total transmission power. Equivalently, QOSTFCscan provide higher data rates with …
Higher Order Parallel Concatenated Spreading Matrices Ofdm, Xiaojing Huang, Ibrahim Raad
Higher Order Parallel Concatenated Spreading Matrices Ofdm, Xiaojing Huang, Ibrahim Raad
Faculty of Informatics - Papers (Archive)
This paper studies higher order parallel concatenated spreading matrix OFDM (PCSM-OFDM). PCSM-OFDM was shown to greatly improve on the classic Block Spread OFDM, this paper continues the work on PCSM-OFDM and studies higher order in terms of an increased number of streams. This shows that with the increase in the streams the overall BER performance improves.