Multiuser subcarrier allocation for OFDM transmission using adaptive modulation

Cheong Yui Wong, Roger S. Cheng, Khaled Letaief, Ross D. Murch

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

29 Citations (Scopus)

Abstract

A multiuser OFDM (Orthogonal Frequency Division Multiplexing) downlink transmission with adaptive modulation is considered. Assuming that the base station knows the instantaneous channel gains for all users, we propose an algorithm which minimizes the total transmit power by assigning, to each user, a set of subcarriers within an OFDM symbol and by determining, for each sub-carrier, the number of bits to be transmitted and the power level used. We obtained the performance of our proposed algorithm in a multiuser frequency selective fading environment with various root-mean-square (RMS) delay spread. The results show that our proposed algorithm outperforms conventional OFDM systems with or without optimal bit allocation using TDMA or FDMA as multiaccess techniques. We have also quantified the improvement in terms of the required transmit power, for fixed bit error rate.

Original languageEnglish
Title of host publicationIEEE VTS 50th Vehicular Technology Conference, VTC 1999-Fall
Pages479-483
Number of pages5
Volume1
Publication statusPublished - 1999
Externally publishedYes
EventIEEE VTS 50th Vehicular Technology Conference, VTC 1999-Fall - Houston, TX, USA
Duration: 19 Sep 199922 Sep 1999

Other

OtherIEEE VTS 50th Vehicular Technology Conference, VTC 1999-Fall
CityHouston, TX, USA
Period19/9/9922/9/99

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ASJC Scopus subject areas

  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Applied Mathematics

Cite this

Wong, C. Y., Cheng, R. S., Letaief, K., & Murch, R. D. (1999). Multiuser subcarrier allocation for OFDM transmission using adaptive modulation. In IEEE VTS 50th Vehicular Technology Conference, VTC 1999-Fall (Vol. 1, pp. 479-483)