scholarly journals An Oversampling-based Correlator-type Receiver for DCSK Communication Systems Over Generalized Flat Rayleigh Fading Channels

2016 ◽  
Author(s):  
Quyen Xuan Nguyen
Keyword(s):  
Fading Channels ◽  
System Performance ◽  
Communication Systems ◽  
Rayleigh Fading ◽  
Sampling Rate ◽  
Multipath Channels ◽  
Noise Power ◽  
Noise Power Spectral Density ◽  
Transmission Period ◽  
Flat Rayleigh Fading

This paper proposes an oversampling-based correlator-type receiver for Differential Chaos-shift Keying (DCSK) communication systems, which can exploit the flat-fading characteristic of multipath channels in order to improve the system performance. At the receiver, the incoming signal is sampled with a sampling rate higher than chip rate before feeding to a correlator. This oversampling step aims to specifically determine delayed-signal components from fading multipath channels, which can be combined together by the correlator in order to increase the ratio of signal-to-noise at its output. In particular, the performance of the proposed receiver is investigated by means of a generalized flat Rayleigh fading channel which has one primary path (i.e., the path having the shortest transmission period) and multiple secondary paths (i.e., the other remaining paths with delays). Mathematical models in discrete-time domain for the conventional transmitter, generalized channel, and proposed receiver are proposed and analyzed. The theoretical bit-error-rate (BER) expression is first derived and then distribution histogram for the ratio of variable bit energy to noise power spectral density is computed. The BER performance is finally estimated by integrating the BER expression over all possible values of the histogram. Numerical simulations with specific parameters are carried out and then simulated performances are shown in comparison to estimated ones. Obtained results point out that the system performance is significantly improved when the number of secondary paths increases.

scholarly journals Performance Assessment of OFDM System using Reed-Solomon Codes over Fading Channels

2018 ◽  
Vol 2 (2) ◽  
pp. 48
Author(s):  
N.M.A.E.D. Wirastuti ◽  
I.M.A. Suyadnya ◽  
D.C. Khrisne
Keyword(s):  
Fading Channels ◽  
Channel Coding ◽  
System Performance ◽  
Orthogonal Frequency Division Multiplexing ◽  
Rayleigh Fading ◽  
Noise Power ◽  
Ofdm System ◽  
Rs Codes ◽  
Reed Solomon Codes ◽  
Coded Ofdm

This paper study the performance of Orthogonal Frequency Division Multiplexing (OFDM) system over AWGN and Rayleigh fading channels. OFDM performs multi-carrier transmission where all the subcarriers are orthogonal to each other. The channel coding was applied to improve the OFDM system performance. Reed Solomon (RS) codes was chosen that an efficient channel coding algorithm and has intense error correction ability. Adding the benefits of multicarrier OFDM system and Reed Solomon codes to achieve the expected system performance. The coded OFDM system was modeled over and simulated using Matlab. The bit error rate (BER) and energy bit (Eb) per noise power density (No) was performed during system simulations. QPSK modulation was used to modulate the random bits. From the simulation results It can be seen that BER vs. EB/No parameter for Coded OFDM system lower than uncoded OFDM. This was because RS codes succeed to correcting the error generated along data transmission.

scholarly journals Modeling of Non-WSSUS Double-Rayleigh Fading Channels for Vehicular Communications

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Carlos A. Gutiérrez ◽  
J. J. Jaime-Rodríguez ◽  
J. M. Luna-Rivera ◽  
Daniel U. Campos-Delgado ◽  
Javier Vázquez Castillo
Keyword(s):  
Fading Channels ◽  
Communication Systems ◽  
Rayleigh Fading ◽  
Channel Model ◽  
Closed Form Solution ◽  
Multipath Fading ◽  
Rayleigh Distribution ◽  
Rayleigh Fading Channels ◽  
Small Scale ◽  
Time Frequency

This paper deals with the modeling of nonstationary time-frequency (TF) dispersive multipath fading channels for vehicle-to-vehicle (V2V) communication systems. As a main contribution, the paper presents a novel geometry-based statistical channel model that facilitates the analysis of the nonstationarities of V2V fading channels arising at a small-scale level due to the time-varying nature of the propagation delays. This new geometrical channel model has been formulated following the principles of plane wave propagation (PWP) and assuming that the transmitted signal reaches the receiver antenna through double interactions with multiple interfering objects (IOs) randomly located in the propagation area. As a consequence of such interactions, the first-order statistics of the channel model’s envelope are shown to follow a worse-than-Rayleigh distribution; specifically, they follow a double-Rayleigh distribution. General expressions are derived for the envelope and phase distributions, four-dimensional (4D) TF correlation function (TF-CF), and TF-dependent delay and Doppler profiles of the proposed channel model. Such expressions are valid regardless of the underlying geometry of the propagation area. Furthermore, a closed-form solution of the 4D TF-CF is presented for the particular case of the geometrical two-ring scattering model. The obtained results provide new theoretical insights into the correlation and spectral properties of small-scale nonstationary V2V double-Rayleigh fading channels.

scholarly journals Bit error probability of coherent M-ary PSK over flat Rayleigh fading channels

2005 ◽  
Vol 41 (21) ◽  
pp. 1186 ◽  
Author(s):  
J. Lassing ◽  
E.G. Ström ◽  
E. Agrell ◽  
T. Ottosson
Keyword(s):  
Fading Channels ◽  
Error Probability ◽  
Rayleigh Fading ◽  
Rayleigh Fading Channels ◽  
Bit Error Probability ◽  
Flat Rayleigh Fading
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