Degrees of Freedom in Adaptive Modulation

subailong520

We examine adaptive modulation schemes for flatfading
channels where the data rate, transmit power, and instantaneous
BER are varied to maximize spectral efficiency, subject to an
average power and BER constraint. Both continuous-rate and discrete-
rate adaptation are considered, as well as average and instantaneous
BER constraints.We find the general form of power, BER,
and data rate adaptation that maximizes spectral efficiency for a
large class of modulation techniques and fading distributions. The
optimal adaptation of these parameters is to increase the power
and data rate and decrease the BER as the channel quality improves.
Surprisingly, little spectral efficiency is lost when the power
or rate is constrained to be constant. Hence, the spectral efficiency
of adaptive modulation is relatively insensitive to which degrees of
freedom are adapted.

chujn

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cnyqw

下来看看，谢谢。

cnyqw

great, thanks

hjgcqq123

多谢分享！！！！！！！

yulai860

下来看看，谢谢。

efong

thank you