Reply To: BLER Error in Uplink Link Level Simulator using multisim

Yeon Tan

Hi Stefan,

I am glad you finally replied my questions. You mentioned about all simulation parameters, are you referring to load_params_doc.m, load_params_doc_antenna.m and load_params_doc_mimo.m and quicktest_load_params.m under Example folder ? I thought simulation.parameter_scripts = {‘examples/load_params_doc_antenna’}; means it only runs load_params_doc_antenna.m script ?

Besides, i am now using multisim_doc_example.m to run simulation instead. Yeah, i do use simulation.SNR_vec = linspace(-10,30,30); during the period you didn’t reply my questions which it takes 30 points and runs quite a while to get results. The results appears to be better and show curve line instead of straight line. And i use simulation.N_subframes = 1000; Now i have questions to ask: Why sometimes my BLER plot will show vertical straight line and sometimes show zero value ? Is it possible to get vertical straight line ? I guess zero value is acceptable.

By the way, i discovered that when i set LTE_params.UE_config.CQI_fb to false and use simulation.cqi_i = 7; my BLER curve appears to be Inverted J Curve. Unlike the previous simulation which BLER curve appears to be fluctuate ( up and down ) from 0 dB to 30 dB, using CQI feedback set to false the BLER curve appears to be Inverted J Curve. Can i explain it by saying using CQI Feedback set to false means CQI value is fix , so is the modulation order and thus the error keeps reducing while SNR increases ?

I also want to ask about the LTE_params.ChanMod_config.type like PedA, PedB , VehA, TU and so on. However, i cannot find any information about them with the documentation file as well as online resource. Is that any way i can approach ?

Last but not least, the uplink version i used is the latest version which is v1.5. I use 20 MHz bandwidth because it is a standard bandwidth used in the operator company here.

Thanks in advance for your kindly reply.