  In this letter, we study the ergodic capacity of a maximum ratio combining
(MRC) Rician fading channel with full channel state information (CSI) at the
transmitter and at the receiver. We focus on the low Signal-to-Noise Ratio
(SNR) regime and we show that the capacity scales as (L Omega/(K+L)) SNR
log(1/SNR), where Omega is the expected channel gain per branch, K is the
Rician fading factor, and L is the number of diversity branches. We show that
one-bit CSI feedback at the transmitter is enough to achieve this capacity
using an on-off power control scheme. Our framework can be seen as a
generalization of recently established results regarding the fading-channels
capacity characterization in the low-SNR regime.
