The sum-rate capacity of a noncoherent multiple-access Rician fading
channel is investigated under three different categories of power
constraints: individual per user peak-power constraints, individual
per user average-power constraints, or a global power-sharing
average-power constraint. Upper and lower bounds on the sum-rate
capacity are derived and it is shown that at high signal-to-noise
ratio the sum-rate capacity only grows double-logarithmically in the
available power. The asymptotic behavior of capacity is then analyzed
in detail and the exact asymptotic expansion is derived including its
second term, the so called fading number. It is shown that the fading
number is identical to the fading number of the single-user Rician
fading channel that is obtained when only the user seeing the best
channel is transmitting and all other users are switched off at all
times. This pessimistic result holds independently of the type of
power constraint that is imposed.


Channel capacity, fading number, flat fading, high signal-to-noise
ratio (SNR), multiple-access channel (MAC), multiple-input
single-output (MISO), multiple users, Rician fading.

-||-   _|_ _|_     /    __|__   Stefan M. Moser
[-]     --__|__   /__\    /__   Senior Researcher & Lecturer, ETH Zurich, Switzerland
_|_     -- --|-    _     /  /   Adj. Professor, National Chiao Tung University (NCTU), Taiwan
/ \     []  \|    |_|   / \/    Web: http://moser-isi.ethz.ch/

Last modified: Fri Oct 29 13:34:53 UTC+8 2010