Finite-state Markov modeling of fading channels - a survey of principles and applications <s> FASTER CHANNEL SIMULATIONS <s> Finite-state Markov channel (FSMC) models are useful for analysing radio channels with nonindependent fading, which give rise to bursty channel errors. In the paper the FSMC model is constructed by partitioning the dynamic range of the fade amplitude into finite number of intervals and representing each interval as a ‘state’ in the model. Transitions between these channel states thus characterise the physical fading process. Based on the Nakagami-m distribution, a new analytical formulation for the state transition probability is presented and validated for channels with arbitrary degrees of time-interleaving. The resultant FSMC model is shown to be applicable to a wide range of practical fading channels, including diversity-combined channels and multicarrier channels. <s> BIB001 </s> Finite-state Markov modeling of fading channels - a survey of principles and applications <s> FASTER CHANNEL SIMULATIONS <s> We form a finite-state Markov channel model to represent Rayleigh fading channels. We develop and analyze a methodology to partition the received signal-to-noise ratio (SNR) into a finite number of states according to the time duration of each state. Each state corresponds to a different channel quality indicated by the bit-error rate (BER). The number of states and SNR partitions are determined by the fading speed of the channel. Computer simulations are performed to verify the accuracy of the model. <s> BIB002 </s> Finite-state Markov modeling of fading channels - a survey of principles and applications <s> FASTER CHANNEL SIMULATIONS <s> We designed a multi-channel Nakagami fading simulator by modeling the received combined signal-to-noise ratio as a finite-state Markov chain, following a previously proposed approach. Our model generates directly the error process at the output of a diversity receiver and can emulate selection, maximal-ratio, and equal-gain combining. As the order of diversity increases, the savings in computational complexity improve linearly with respect to a traditional waveform simulator. The level crossing rates of the simulated envelope are shown to be very close to their theoretical values. The simulator's performance is also evaluated in terms of the accuracy of the obtained bit error rates, for both uncoded and coded systems. The simulator speeds up the performance evaluation of high-rate communication links where a high number of samples is needed. <s> BIB003
Obtaining a closed-form expression for the performance measure in a coded system may not be always possible. However, FSMC models are still useful in providing more efficient error burst modeling and faster channel simulations. Instead of the time-consuming process of passing the transmitted signal through the TV-FFC and processing the received signal to determine if an erroneous decision is made, one can replace the original fading channel with an FSMC model and then use the FSMC model to directly simulate samples of the channel error process at the output of the demodulator in a much faster way BIB003 . Using FSMC models instead of Clarke's model for channel simulation becomes a major advantage for analyzing more complex communication systems which include diversity BIB003 , BIB001 or multicarrier techniques BIB001 . Once the FSMC states, state transition probabilities, and probability of error in each state is determined, channel simulation comprises of generating two sequences of (independent) uniform random variables, one to decide whether state transition has taken place and the other to determine whether an error has occurred in each state BIB003 (see the end of section on FSMC models). The authors in BIB003 have used this simulation model to study the coded BER in three main diversity schemes. FSMC models have been also used in BIB002 for faster and more convenient system-level analysis of wireless video transmission by avoiding bit-level simulations.