Title :
On the capacity of some channels with channel state information
Author :
Caire, Giuseppe ; Shamai, Shlomo
Author_Institution :
Mobile Commun. Group, Inst. Eurecom, Sophia Antipolis, France
fDate :
9/1/1999 12:00:00 AM
Abstract :
We study the capacity of some channels whose conditional output probability distribution depends on a state process independent of the channel input and where channel state information (CSI) signals are available both at the transmitter (CSIT) and at the receiver (CSIR). When the channel state and the CSI signals are jointly independent and identically distributed (i.i.d.), the channel reduces to a case studied by Shannon (1958). In this case, we show that when the CSIT is a deterministic function of the CSIR, optimal coding is particularly simple. When the state process has memory, we provide a general capacity formula and we give some more restrictive conditions under which the capacity has still a simple single-letter characterization, allowing simple optimal coding. Finally, we turn to the additive white Gaussian noise (AWGN) channel with fading and we provide a generalization of some results about capacity with CSI for this channel. In particular, we show that variable-rate coding (or multiplexing of several codebooks) is not needed to achieve capacity and, even when the CSIT is not perfect, the capacity achieving power allocation is of the waferfilling type
Keywords :
AWGN channels; channel capacity; fading channels; probability; statistical analysis; variable rate codes; AWGN channel; CSI signals; Shannon; additive white Gaussian noise channel; channel capacity; channel input; channel state information; codebooks multiplexing; conditional output probability distribution; deterministic function; fading; general capacity formula; i.i.d.; independent identically distributed signals; memory; optimal coding; power allocation; receiver; single-letter characterization; state process; transmitter; variable-rate coding; waferfilling capacity; AWGN; Additive white noise; Capacity planning; Channel capacity; Channel state information; Fading; Mobile communication; Probability distribution; Signal processing; Transmitters;
Journal_Title :
Information Theory, IEEE Transactions on