# LTE sim main launcher demo femtocell calculations equations

Viewing 10 posts - 1 through 10 (of 10 total)
• Author
Posts
• #4178
Farhan
Participant

I am running the “LTE_sim_Main_Launcher_demo_femtocell”

After successful completion of simulation, it is displaying “LTE_GUI_show_UEs_and_cells” where The grey text box contains the simulation statistic’s. I have following question’s:

1. How Average UE thorughput and Average UE spectral efficiency is calculated? Where can i find the exact mathematical equations / theoratical expressions for these two parameter’s (Which .m File in particular contain’s the implementation of these equations)?
2. The spectral efficiency is calculated in bit/s/Hz where in these result’s spectral efficiency is being calculated in bit/cu. How they are related? What bit/cu is representing?

#4246
Farhan
Participant

#4256

Hi,

the calculation of the spectral efficiency as well as the average UE throughput is found in +tracing.ueTrace.calculate_final_average_*.

Best regards,
Martin.

#4258
Farhan
Participant

Hi,

Thanks for your response, i got the function’s which i am pasting below however can you please share theoretical expressions / equations of UE thorughput and UE spectral efficiency ?

Function to calculate average energy per bit “function calculate_final_average_energy_per_bit(obj)” is written, however i am unable to find the result of this function on GUI along with above mentioned parameter’s

Regards,
Farhan

``````function calculate_final_average_spectral_efficiency_bit_per_cu(obj)
TTIs_to_ignore              = obj.parent_results_object.TTIs_to_ignore_when_calculating_aggregates;
total_bits                  = sum(double(obj.ACK).*double(obj.TB_size),1);
TTIs_to_account_for         = true(1,length(obj.assigned_RBs));
TTIs_to_account_for(1:TTIs_to_ignore)    = false; % Ignore TTIs where no feedback information was available
TTIs_to_account_for(obj.UE_was_disabled) = false;

sum_total_bits              = sum(total_bits(TTIs_to_account_for));
channel_uses_total          = sum(double(obj.assigned_RBs(TTIs_to_account_for)))*12*14;
obj.average_spectral_efficiency_bit_per_cu = sum_total_bits ./ channel_uses_total;
end

% Calculates the average UE throughput based on the TB_size, ACK, and assigned_RBs variables
function calculate_final_average_throughput_Mbps(obj)
TTIs_to_ignore                           = obj.parent_results_object.TTIs_to_ignore_when_calculating_aggregates;
total_bits                               = sum(double(obj.ACK).*double(obj.TB_size),1);
TTIs_to_account_for                      = true(1,length(obj.assigned_RBs));
TTIs_to_account_for(1:TTIs_to_ignore)    = false; % Ignore TTIs where no feedback information was available
TTIs_to_account_for(obj.UE_was_disabled) = false;

sum_total_bits              = sum(total_bits(TTIs_to_account_for));
accounted_TTIs              = sum(TTIs_to_account_for);
obj.average_throughput_Mbps = sum_total_bits / (accounted_TTIs*obj.TTI_length_s) / 1e6;
end``````
#4261

Dear Farhan,

this function exactly represent the reason of doing simulations, as it evalutes the correctly received transport blocks and accumulates the corresponding transmitted bits.
The average energy per bit is not contained in the GUI. You will have to read it out from the simulation traces, which are in your MATLAB workspace when showing the results.

Best regards,
Martin.

#4263
Farhan
Participant

Hi,

Thank’s for your prompt response, i appreciate it and it really helped alot, However i am having confusion regarding The spectral efficiency, as in these result’s spectral efficiency is being calculated in bit/cu. What bit/cu is representing and is it same as bit/s/Hz?

The theoretical expressions / mathematical equations of how UE spectral efficiency is calculated would be helpful in understanding it.

Best Regards,
Farhan

#4305
Farhan
Participant

Hi,

Appreciate it if anyone can reply to the above mentioned query. Thanks

#4330
Farhan
Participant

Hi Martin,

I am trying to read The average energy per bit out from the simulation traces, which are in MATLAB workspace but i am unable to find it. Can you please help in this regard.

Regards,
Farhan

#4335
Farhan
Participant

Hi,

I can now read average energy per bit from traces for individual UE’s but i want to output in GUI the mean of all selected UE’s. I have edited the code in LTE_GUI_show_UEs_and_cells.m to display the Average energy per bit but i am getting 0.00 j/b in GUI. Can you please check where else i need to make change (Any other .m file?). I have written this below code as it was not there.

``````   to_average                = [the_UE_traces(UEs_to_plot_lin).average_energy_per_bit];
to_average                = to_average(isfinite(to_average));
mean_average_energy= mean(to_average);

``````

‘%s\n’,…
‘Simulations statistics:\n\n’,…
‘%g UEs\n’,…
‘Avg. UE throughput: %3.2f Mb/s\n’,…
‘Avg. UE spectral eff.: %3.2f bit/cu\n’,…
`Avg. UE average_energy_per_bit .: %3.2f J/b\n’,…
‘Avg. RBs/TTI/UE: %3.2f RBs\n’,…
‘Rank Indicator (RI) distribution:’,…
],…
sep,…
length(UEs_to_plot_lin),…
mean_average_throughput,…
mean_average_spectral_eff,…
mean_average_energy,…
mean_average_RBs_per_TTI);

#4448

Hi,

try to set a break point in LTE_GUI_show_UEs_and_cells, to see the result of “to_average”.

Best regards,
Martin.

Viewing 10 posts - 1 through 10 (of 10 total)
• The forum ‘Vienna LTE-A Downlink System Level Simulator’ is closed to new topics and replies.