Report on Channel Model Chrysovalantis Kosta Good Afternoon Sir This afternoon I will share with you my report of Femtocell Let’s start with femtocell presentation!

Agenda Wireless Channel Characteristics Path loss Shadowing And how we may simulate these??

Wireless Channel Characteristics Wireless Channel of different com terminal Path Loss Large scale Long duration Shadowing Medium Scale Medium Duration Multipath Fading Small Scale Small Duration Generally, the wireless channel of different communication terminals can be expressed with a multiplicative propagation mechanism of three nearly independent fading components: path loss, shadowing and multipath. Each one of them has a different scale and different duration. It can be scaled as ‘large’, ‘medium’ and ‘small’ and It can be termed as ‘long, ‘medium’ and ‘short’, according its duration. fading effect ? duration ?

Path Loss (Large-scale fading effect) Example Path Loss for Urban Free Space Loss   is the path loss in decibels   is the path loss exponent is the distance between the transmitter and the receiver, is a constant which accounts for system losses   n=3.76 C= 128 colorbar terminals can be formulated as C= 127   n=3

Example from LTE simulator 50 100 150 200 20 40 60 80 120 140 160 180 70 90 110 130 networkPathlossMap.plot_pathloss(cell ID) / .plot_pathloss_all

Shadowing (Medium-Scale Fading effect) Shadowing (Log-normal fading loss) Shadow fading is cause by obstacles in the propagation path Mainly from irregularities of the geographical terrain. We may simulate this fading by using a normal/guassian variable with mean =0 and a positive std from 8 – 10 dB.

Shadowing (Medium-Scale Fading effect) Shadowing (Log-normal fading loss) 1-D dimensional shadowing New value Old value Forgetting factor

Shadowing (macro-cell diversity ) As shadowing effects occur over a large area, in order to be able to capture the dynamics affecting macro-cell diversity in a realistic way, a two-dimensional Gaussian process with appropriate spatial correlation is desirable.

Shadowing Shadowing (Log-normal fading loss) 2D dimensional shadowing Impulse Response Table Gaussian Table 2D convolution

Evaluation of Shadowing model Calculating the mean value (should be 0) Calculating the std value (should be std) Plotting the histogram

Example from LTE simulator networkPathlossMap.plot_shadowing(cell ID) /.plot_both_path_shawdow_all

Examples from LTE simulator

Examples from LTE simulator networkPathlossMap.plot_pathloss_all networkPathlossMap.plot_both_path_shawdow_all

Questions and Answers This brings me to the end of my presentation! Thank you for your attention! Now, I would be happy answering any question that you may have !

Fast Fading Channel Model The channel model consists into mobile wireless channel with L moving scatters. The Fourier transform of the channel response is the time varying frequency response which can be described as: where hl  the complex amplitude τl  time delay of the lth path.

Simulating flat fast fading Inputs: Ns : number of samples in the generated fading impulse response Ts : Sampling Interval in seconds Fd : Maximum Doppler Frequency in Hz M : # of Sinusoids Output: Gt : complex channel impulse response =

Modeling flat fast fading (Matthias method ) Fd Ns & Ts

Evaluation of flat fast fading channel model Phase 1 Autocorrelation of Real part (Fig.1) Autocorrelation of Imag. part (Fig.2) Cross correlation of Real part (Fig.3) Autocorrelation of Amplitude (Fig.4) Phase 2 Normalized LCR (Level crossing rate) (Fig.5) Normalized AFD (Average Fading Dur.) (Fig.6) Fading Amplitude Fig.7

Matthias Patzold Autocorrelation of Real part Autocorrelation of Imag. part Cross correlation of Real part Autocorrelation of Amplitude

Jakes Model Autocorrelation of Real part Autocorrelation of Imag. part Cross correlation of Real part Autocorrelation of Amplitude

Yahong Autocorrelation of Real part Autocorrelation of Imag. part Cross correlation of Real part Autocorrelation of Amplitude

Optimal Autocorrelation of Real part Autocorrelation of Imag. part Cross correlation of Real part Autocorrelation of Amplitude

Matthias Patzold Level crossing rate Average Fading Duration Fading Amplitude

Jakes Model Level crossing rate Average Fading Duration Fading Amplitude

Yahong Level crossing rate Average Fading Duration Fading Amplitude

Channel Impulse Response Signal power in dB Delay of each path in sec

Examples of ITU models Here, we display some examples of most favourable ITU models. Some of the m they may charactarize as indoors or outdoor depending on their average delay spread. All these are modeled in Vienna.

Simulating Selective Fading Simulate multiple flat fading layers Multiply and shift according to the channel profile (in terms of multipath signal strength and delay)

Example of ITU model using PedB Doppler frequency at 100Hz Sampling interval 1/1920000 Number of Samples 4000 Number of Sinusoids 10 Furthermore, we model the channel impulse response of the PedB channel model at this speed The simulation code examples will be available on my personal webpage. On this axis we may impulse response in time domain And on this in frequency domain. The frequency Doppler of this example is 100Hz, the total bandwidth is 1.4 MHz for 4 secs. Note that the points with dark colour depict deep fading and the points with red color depict non-deep fading.

Questions and Answers This brings me to the end of my presentation! Thank you for your attention! Now, I would be happy answering any question that you may have !