Performance of scalable feedback schemes for downlink OFDMA

Jieying Chen*, Randall A Berry, Michael L Honig

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution


In a downlink Orthogonal Frequency Division Multiple Access (OFDMA) system, optimally allocating sub-channels to the users can require excessive feedback. We consider two limited feedback schemes to manage this overhead: a sequential scheme in which each user sends compressed feedback bits over consecutive time slots and a contention scheme in which users send their feedback using a random access protocol. In previous work we characterized the asymptotic performance of these schemes as the number of users and number of sub-channels scale with fixed load p. That analysis explicitly models the feedback overhead assuming a finite coherence time and fixed feedback rate per sub-channel. In this paper, we revisit this model, and first characterize the performance of both schemes as a function of p. We then study the performance of these schemes for a finite system via simulation. Finally we examine the relative performance of the two schemes as a function of the load, the available feedback rate, and additional overhead per transmission (e.g., due to synchronization).

Original languageEnglish (US)
Title of host publicationMilitary Communications Conference, MILCOM 2007
StatePublished - Dec 1 2007
EventMilitary Communications Conference, MILCOM 2007 - Orlando, FL, United States
Duration: Oct 29 2007Oct 31 2007


OtherMilitary Communications Conference, MILCOM 2007
Country/TerritoryUnited States
CityOrlando, FL

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


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