Résumé:
In this paper we present a mathematical technique
for determining the optimum transmission rate and packet size in
wireless system that have multi-carriers for OFDM modulation in
downlink transmission. The throughput is defined as the number
of bits per second correctly received. Trade-offs between the
throughput and the operation range are observed, and equations
are derived for the optimal choice of the design variables. These
parameters are SNR dependent and can be adapted dynamically
in response to the mobility of a wireless data terminal. We also
look at the joint optimization problem involving all the design
parameters together. We find, however, that not all of the three
parameters (b,SNR,L) need to be adapted simultaneously: in the
low SNR region it is achieved by adapting the symbol rate so
that the received SNR per symbol stays at some preferred value.
Finally, we give a characterization of the optimal parameter
values as functions of received SNR
