Abstract
We study in this paper an application of hierarchical constellations (known also as nonuniform, asymmetric, and multi-resolution constellations) in conjunction with a retransmission strategy to multiclass data transmission over block fading channels. The basic idea is to assign different hierarchies of a hierarchical quadrature amplitude modulation (QAM) to different classes of data according to their transmission priorities (quantified through their average throughput and delay requirements) and then to apply a truncated retransmission scheme to each hierarchy (or equivalently each class of data) separately in order to meet the delay requirements of the various services. We present closed-form expressions for the average packet loss rate and the packet transmission rate of each class of data over Nakagami-m block fading channel. Some numerical results show that the proposed hierarchical scheme outperforms a classical time-multiplexing scheme employing power-controlled uniform QAM constellations for multi-class data transmission over block fading channels.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 934-938 |
| Number of pages | 5 |
| Journal | IEEE Vehicular Technology Conference |
| Volume | 59 |
| Issue number | 2 |
| State | Published - 2004 |
| Externally published | Yes |
| Event | 2004 IEEE 59th Vehicular Technology Conference, VTC2004-Spring: Towards a Global Wireless World - Milan, Italy Duration: May 17 2004 → May 19 2004 |
ASJC Scopus subject areas
- Applied Mathematics
- Electrical and Electronic Engineering
- Computer Science Applications