神马文学网OFDMA Resource Allocation
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OFDMA Resource Allocation
OFDMA, also referred to as Multiuser-OFDM, is being considered as a modulation and multiple access method for 4th generation wireless networks. OFDMA is an extension of Orthogonal Frequency Division Multiplexing (OFDM), which is currently the modulation of choice for high speed data access systems such as IEEE 802.11a/g wireless LAN (WiFi) and IEEE 802.16a/d/e wireless broadband access systems (WiMAX).
In current OFDM systems, only a single user can transmit on all of the subcarriers at any given time, and time division or frequency division multiple access is employed to support multiple users. The major setback to this static multiple access scheme is the fact that the different users see the wireless channel differently is not being utilized. OFDMA, on the other hand, allows multiple users to transmit simultaneously on the different subcarriers per OFDM symbol. Since the probability that all users experience a deep fade in a particular subcarrier is very low, it can be assured that subcarriers are assigned to the users who see good channel gains on them.
My research considers basestation allocation of subcarriers and power to each user to maximize the sum of user data rates, subject to constraints on total power, bit error rate, and proportionality among user data rates. Details on this research work can be found in my SIPS 2004 paper, presentation, and simulation files.
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contact me at: wongic@mail.utexas.edu
This page was last updated on
11/15/2004 10:11 AM