[Haseeb Qureshi]

Hi Team

I am new to this simulator.

Please guide me to create an environment in which users should only communicate with femto cells without the involvement of macro cells. My aim is to create a self optimising environment of femtocells. I can create an environment with macrocells only and macrocells working with femtocells, but unable to achieve a network with femtocells only. Is there any way I can turn off macrocell? Please also tell me how femtocell is connected to macrocell in this simulator? Is it via cable?

Plus also guide how can I control the positioning of femtocells and UEs?

Waiting for four help and guidance.

Thanks in advance.

Kind Regards
Haseeb

[Martin Müller]

Dear Haseeb,

The scenario that is defined in the file “LTE_sim_main_launcher_femtocells.m” considers a fixed amount of femto cells per macro cell. Using this as a reference, you can eliminate the macro cells from your simulation by including the following lines in your scenario file:

LTE_config.antenna.antenna_gain_pattern = ‘omnidirectional’; % creates a single macro BS (instead of three sector BSs)
LTE_config.nr_eNodeB_rings = 0; % creates only one BS-site in the center
LTE_config.eNodeB_tx_power = 0; % transmit power in Watt – will set the cell size of the macro BS to 0

With the line

LTE_config.femtocells_config.femtos_per_cell = 20;

you can then directly control the absolute number of femtos that will be placed in your scenario (in this case 20). By default, the placement option

LTE_config.femtocells_config.spatial_distribution = ‘constant femtos per cell’;

is chosen, which places the femtos randomly within your cell (in this case in the whole region of interest).

Then setting

LTE_config.UE_per_eNodeB = [0 2]; % First number refers to ‘macro’, second to ‘femto’ ,i.e. [Nr_of_UEs_per_Macro Nr_of_UEs_per_Femto]

will create 2 UEs per femto-cell (randomly placed in the cell).

Femtocells are considered to have an independent backhaul link and are thus performing scheduling etc. independently. Only for placement they are assigned to a BS object.

Best regards,
Martin

[Haseeb Qureshi]

Hi Martin

Thank you so much for your help and guidance. It is much appreciated.

Based on your suggestions I have added the lines and done the modifications in the “LTE_sim_main_launcher_femtocells.m” file but the simulation does not run through.

I am receiving the errors and could not able to solve them.

The “LTE_sim_main_launcher_femtocells.m” file that I am running is:

close all force;
clc;
cd ..
%clear all
%clear global;
%clear classes;

simulation_type = ‘tri_sector_plus_femtocells’;

% Possible simulation types now:
% – ‘tri_sector’
% – ‘tri_sector_tilted’, ‘tri_sector_tilted_4x2’, ‘tri_sector_tilted_4x4’
% – ‘tri_sector_plus_femtocells’
% – ‘six_sector_tilted’
% – ‘capesso_pathlossmaps’
% – ‘omnidirectional_eNodeBs’

LTE_config = LTE_load_params(simulation_type);

%% If you want to modify something taking as a base the configuration file, do it here: here an example is show that changes the inter-eNodeB distances based on the LTE_load_params_hex_grid_tilted config file.

% Some changes to the base configuration, in case you would need/want them
LTE_config.show_network = 2;
LTE_config.nTX = 1;
LTE_config.nRX = 1;
LTE_config.tx_mode = 1;
LTE_config.scheduler = ’round robin’;
LTE_config.UE_per_eNodeB = [0 2]; % First number refers to ‘macro’, second to ‘femto’ ,i.e. [Nr_of_UEs_per_Macro Nr_of_UEs_per_Femto]
LTE_config.macroscopic_pathloss_model = ‘TS36942’;
LTE_config.shadow_fading_type = ‘none’;
LTE_config.channel_model.type = ‘TU’;
LTE_config.simulation_time_tti = 10;
LTE_config.feedback_channel_delay = 1;
LTE_config.map_resolution = 5;
LTE_config.compact_results_file = true;
LTE_config.delete_ff_trace_at_end = true;
LTE_config.cache_network = false;
LTE_config.UE_cache = false;
LTE_config.UE_cache_file = ‘auto’;
LTE_config.pregenerated_ff_file = ‘auto’;
LTE_config.trace_version = ‘v1’;
LTE_config.adaptive_RI = 0;
LTE_config.keep_UEs_still = true;

% Femto specific
LTE_config.femtocells_config.femtos_per_cell = 20;

LTE_config.antenna.antenna_gain_pattern = ‘omnidirectional’; % creates a single macro BS (instead of three sector BSs)
LTE_config.nr_eNodeB_rings = 0; % creates only one BS-site in the center
LTE_config.eNodeB_tx_power = 0; % transmit power in Watt – will set the cell size of the macro BS to 0

LTE_config.femtocells_config.tx_power_W = 10^(20/10)*1/1000;
LTE_config.femtocells_config.mode = ‘CSG’;
LTE_config.femtocells_config.macroscopic_pathloss_model_settings.wall_loss = 20;
LTE_config.femtocells_config.macroscopic_pathloss_model_settings.penetration_loss = LTE_config.femtocells_config.macroscopic_pathloss_model_settings.wall_loss; % Desired signal experiences penetration loss

%%
% Simulate only UEs in the sectors and femtos of center site:
% Indices of femtos in coverage of center site:
first_center_femto_index = 22 + LTE_config.femtocells_config.femtos_per_cell * 12;
last_center_femto_index = first_center_femto_index + 3 * LTE_config.femtocells_config.femtos_per_cell – 1;
LTE_config.compute_only_UEs_from_this_eNodeBs = [13:15]; [13:15 first_center_femto_index:last_center_femto_index]; [13 14 15 16 17 18 19 20 21 28 29 30 31 32 33 34 35 36 46 47 48 58:100];
LTE_config.default_shown_GUI_cells = [13:15]; [13:15 first_center_femto_index:last_center_femto_index]; [13 14 15 16 17 18 19 20 21 28 29 30 31 32 33 34 35 36 46 47 48 58:100];

%%
output_results_file = LTE_sim_main(LTE_config);

simulation_data = load(output_results_file);
GUI_handles.aggregate_results_GUI = LTE_GUI_show_aggregate_results(simulation_data);
GUI_handles.positions_GUI = LTE_GUI_show_UEs_and_cells(simulation_data,GUI_handles.aggregate_results_GUI);

I am receiving the following errors:

Error using .*
Matrix dimensions must agree.

Error in spatial_distributions.constantElementsPerCellSpatialDistribution/generate_positions (line 33)
elements_sector = (strcmp(networkPathlossMap.site_type,’macro’)*obj.elementsPerCell(1) + …

Error in LTE_init_generate_users_and_add_schedulers (line 38)
UE_positions = UE_spatial_distribution.generate_positions;

Error in LTE_sim_main (line 75)
[UEs, extra_UE_cache_info, LTE_config] =
LTE_init_generate_users_and_add_schedulers(LTE_config,sites,eNodeBs,networkPathlossMap,CQI_mapper,BLER_curves,networkClock);

Error in LTE_sim_main_launcher_femtocells (line 69)
output_results_file = LTE_sim_main(LTE_config);

Please help and guide me how to remove these errors as I am new to this simulator and really struggling with my project to implement on this simulator.
I want to communicate with femtocells only without the involvement of macrocells.

Waiting for your help and guidance.

Thanks in advance.

Kind Regards
Haseeb

[Martin Müller]

Dear Haseeb,

what kind of spatial distribution did you define? When I use

LTE_config.femtocells_config.spatial_distribution = ‘constant femtos per cell’;

(as I wrote in my previous answer), it works fine for me.

Best regards,
Martin

[Haseeb Qureshi]

Hi Martin

Thanks for reply and help. It is much appreciated. I have added the lines as you have suggested but still the simulation does not run through.

I have also added the line
LTE_config.femtocells_config.spatial_distribution = ‘constant femtos per cell’;
but no luck and does not work for me.

I am running this file based on your suggestions:
close all force;
clc;
cd ..
%clear all
%clear global;
%clear classes;

simulation_type = ‘tri_sector_plus_femtocells’;

% Possible simulation types now:
% – ‘tri_sector’
% – ‘tri_sector_tilted’, ‘tri_sector_tilted_4x2’, ‘tri_sector_tilted_4x4’
% – ‘tri_sector_plus_femtocells’
% – ‘six_sector_tilted’
% – ‘capesso_pathlossmaps’
% – ‘omnidirectional_eNodeBs’

LTE_config = LTE_load_params(simulation_type);

%% If you want to modify something taking as a base the configuration file, do it here: here an example is show that changes the inter-eNodeB distances based on the LTE_load_params_hex_grid_tilted config file.

% Some changes to the base configuration, in case you would need/want them
LTE_config.show_network = 2;
LTE_config.nTX = 1;
LTE_config.nRX = 1;
LTE_config.tx_mode = 1;
LTE_config.scheduler = ’round robin’;
LTE_config.UE_per_eNodeB = [0 2]; % First number refers to ‘macro’, second to ‘femto’ ,i.e. [Nr_of_UEs_per_Macro Nr_of_UEs_per_Femto]
LTE_config.macroscopic_pathloss_model = ‘TS36942’;
LTE_config.shadow_fading_type = ‘none’;
LTE_config.channel_model.type = ‘TU’;
LTE_config.simulation_time_tti = 10;
LTE_config.feedback_channel_delay = 1;
LTE_config.map_resolution = 5;
LTE_config.compact_results_file = true;
LTE_config.delete_ff_trace_at_end = true;
LTE_config.cache_network = false;
LTE_config.UE_cache = false;
LTE_config.UE_cache_file = ‘auto’;
LTE_config.pregenerated_ff_file = ‘auto’;
LTE_config.trace_version = ‘v1’;
LTE_config.adaptive_RI = 0;
LTE_config.keep_UEs_still = true;
% Femto specific
LTE_config.femtocells_config.femtos_per_cell = 20;
LTE_config.femtocells_config.tx_power_W = 10^(20/10)*1/1000;
LTE_config.femtocells_config.mode = ‘CSG’;
LTE_config.femtocells_config.macroscopic_pathloss_model_settings.wall_loss = 20;
LTE_config.femtocells_config.macroscopic_pathloss_model_settings.penetration_loss = LTE_config.femtocells_config.macroscopic_pathloss_model_settings.wall_loss; % Desired signal experiences penetration loss

LTE_config.antenna.antenna_gain_pattern = ‘omnidirectional’; % creates a single macro BS (instead of three sector BSs)
LTE_config.nr_eNodeB_rings = 0; % creates only one BS-site in the center
LTE_config.eNodeB_tx_power = 0; % transmit power in Watt – will set the cell size of the macro BS to 0

LTE_config.femtocells_config.spatial_distribution = ‘constant femtos per cell’;

%%
% Simulate only UEs in the sectors and femtos of center site:
% Indices of femtos in coverage of center site:
first_center_femto_index = 22 + LTE_config.femtocells_config.femtos_per_cell * 12;
last_center_femto_index = first_center_femto_index + 3 * LTE_config.femtocells_config.femtos_per_cell – 1;
LTE_config.compute_only_UEs_from_this_eNodeBs = [13:15]; [13:15 first_center_femto_index:last_center_femto_index]; [13 14 15 16 17 18 19 20 21 28 29 30 31 32 33 34 35 36 46 47 48 58:100];
LTE_config.default_shown_GUI_cells = [13:15]; [13:15 first_center_femto_index:last_center_femto_index]; [13 14 15 16 17 18 19 20 21 28 29 30 31 32 33 34 35 36 46 47 48 58:100];

%%
output_results_file = LTE_sim_main(LTE_config);

simulation_data = load(output_results_file);
GUI_handles.aggregate_results_GUI = LTE_GUI_show_aggregate_results(simulation_data);
GUI_handles.positions_GUI = LTE_GUI_show_UEs_and_cells(simulation_data,GUI_handles.aggregate_results_GUI);

I have received the same errors:
Error using .*
Matrix dimensions must agree.

Error in spatial_distributions.constantElementsPerCellSpatialDistribution/generate_positions (line 33)
elements_sector = (strcmp(networkPathlossMap.site_type,’macro’)*obj.elementsPerCell(1) + …

Error in LTE_init_generate_users_and_add_schedulers (line 38)
UE_positions = UE_spatial_distribution.generate_positions;

Error in LTE_sim_main (line 75)
[UEs, extra_UE_cache_info, LTE_config] =
LTE_init_generate_users_and_add_schedulers(LTE_config,sites,eNodeBs,networkPathlossMap,CQI_mapper,BLER_curves,networkClock);

Error in LTE_sim_main_launcher_femtocells (line 66)
output_results_file = LTE_sim_main(LTE_config);

I am using the MATLAB version 2015b. I am not sure whether it could be a version compatibility issue.

Can you please share your result or simulation file with me because it is not working for me.

Waiting for expertise and guidance.

Kind Regards
Haseeb

[Anne]

Dears Haseeb and Martin
Haseeb
In your previous question you ask about how could you control the position of the users have you found the answer?
based on Dr Martin answer the user are randomly placed on the cell but I’m a bit confused because whenever I change the nbr of femto user in the LTE _config. UE_per_eNodeB =[0 x] the femto user still looks like overlapping on the femtocell
base station Would you please be able to help me
for understand that
Kind regards

[Author]

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