On information rates of time-varying fading channels modeled as finite-state Markov channels
Sadeghi, Parastoo and Rapajic, Predrag (2008) On information rates of time-varying fading channels modeled as finite-state Markov channels. IEEE Transactions on Communications, 56 (8). pp. 1268-1278. ISSN 0090-6778Full text not available from this repository.
We study information rates of time-varying flat-fading channels (FFC) modeled as finite-state Markov channels (FSMC). FSMCs have two main applications for FFCs: modeling channel error bursts and decoding at the receiver. Our main finding in the first application is that receiver observation noise can more adversely affect higher-order FSMCs than lower-order FSMCs, resulting in lower capacities. This is despite the fact that the underlying higher-order FFC and its corresponding FSMC are more predictable. Numerical analysis shows that at low to medium SNR conditions (SNR lsim 12 dB) and at medium to fast normalized fading rates (0.01 lsim fDT lsim 0.10), FSMC information rates are non-increasing functions of memory order. We conclude that BERs obtained by low-order FSMC modeling can provide optimistic results. To explain the capacity behavior, we present a methodology that enables analytical comparison of FSMC capacities with different memory orders. We establish sufficient conditions that predict higher/lower capacity of a reduced-order FSMC, compared to its original high-order FSMC counterpart. Finally, we investigate the achievable information rates in FSMC-based receivers for FFCs. We observe that high-order FSMC modeling at the receiver side results in a negligible information rate increase for normalized fading rates fDT lsim 0.01.
|Uncontrolled Keywords:||Markov processes, finite-state Markov channels, channel capacity, fading channels|
|Subjects:||T Technology > T Technology (General)|
T Technology > TK Electrical engineering. Electronics Nuclear engineering
|School / Department / Research Groups:||School of Engineering > Department of Computer & Communications Engineering|
School of Engineering
|Last Modified:||31 Mar 2011 18:21|
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