Adaptive Modulation and Scheduling of IP Traffic over Fading Channels

Nilo Casimiro Ericsson

IEEE Vehicular Technology Conference - VTC'99-Fall
Amsterdam, The Netherlands, September 19-22 1999. © 1999 IEEE

Abstract:

In future packet based wireless communication systems, transmission in the downlink will often dominate the traffic load. High bit-rate applications like WWW-browsing, file transfer, and full motion video will impose strong requirements on the system capacity. An obstacle in this context is the time-variability of the channel: For mobile users, frequently occuring fading dips will cause unnecessary, and capacity degrading, retransmissions.

In this paper we investigate the effect of adaptive modulation, along with time-slot scheduling of IP-like traffic in a scenario involving several types of mobile hosts and one base station. We extend a study of the impact of adaptive modulation and scheduling on the bit-error rate, to include models for packet length and packet inter-arrival, to find the queueing delay imposed by our proposed scheduling algorithm.

Our scheduler keeps the bit error rate at attractively low, prespecified levels, well suited for Forward Error Correction (FEC) codes. Moreover, the scheduler splits the bandwidth between different types of traffic in a desirable way, according to the traffic situation.

Related publications:

Ph.D. Thesis by Nilo Casimiro Ericsson, Oct. 2004.

Licenciate Thesis by Nilo C. Ericsson, June 2001.

IEEE VTC2000-fall paper on combining hybrid-II ARQ with predictive scheduling.
PCC Workshop conference paper
Globecom'99 conference paper on adaptive modulation and predictive scheduling.

Source:

Pdf, 115K.