Channel model of typical urban

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  • #7482
    Kai Cheng Wang
    Participant

    Hello
    Does anyone know that how does channel model of typical urban be implemented in LTE-A downlink system level simulator? By the way, I don’t understand the means of TU_1x1_SIXO_20MHz_500.0Kmph_1s_delay_0_v1_ and TU_BS-1TX_UE-1RX_20MHz_500.0Kmph_1s_v2_ in channel trace file. Can someone tell me? thank you.

    Sincerely
    Kai Cheng Wang

    #7548
    Kai Cheng Wang
    Participant

    Hello

    Can someone answer my question? thanks.

    Sincerely
    Kai Cheng Wang

    #7550

    Dear Kai,

    The typical urban (TU) channel model is a pdp-based channel model. You can find the implementation on +channel_gain_wrappers/pdpChannelFactory.m.

    In the simulator it is possible to generate a channel trace for the first time and then reuse the same in other simulations by setting these parameters to
    LTE_config.cache_network = true;
    LTE_config.delete_ff_trace_at_end = false;

    Otherwise you generate a new trace in each simulation run and delete it at the end of simulation.

    Best regards,
    Fjolla

    #7551
    Kai Cheng Wang
    Participant

    Dear Fjolla
    Thank you for your reply. I still have several questions that I want to ask. Does channel trace save channel matrix? what is different between TU_1x1_SIXO_20MHz_500.0Kmph_1s_delay_0_v1_ and TU_BS-1TX_UE-1RX_20MHz_500.0Kmph_1s_v2_? thank you.

    Sincerely
    Kai Cheng Wang

    #7560

    Dear Kai,

    The channel matrix is saved as UE object for each user.

    Two channnel traces are supported by our simulator:
    – v1 channel trace: enables to determine the optimal precoder for each transmis-sion rank a-priori as the channel H is known a-priori
    – v2 channel trace: supports runtime precoding based on the actual channel H determined at the runtime

    Best regards,
    Fjolla

    #7577
    Kai Cheng Wang
    Participant

    Dear Fjolla
    Your reply helps me a lot, thank you. However, I have some questions that let me confuse. In workspace of MATLAB, I can’t find the channel matrix of every UE. How can I reveal the channel matrix of UE in workspace? Another question, does channel of typical urban consider the doppler effect? thank you.

    Sincerely
    Kai Cheng Wang

    #7619

    Dear Kai,

    For the channel models except the 3GPP 3D model, the channel matrix for the desired channel H_0 and for the interfering channels H_i is can be found from the UE object as:

    obj.downlink_channel.secondary_fast_fading_models(1,1).ff_trace.H_0
    obj.downlink_channel.secondary_fast_fading_models(1,1).ff_trace.H_i

    Yes the typical urban channel model considers the doppler effect. There is a very good paper that might be helpful for you:

    Yahong Rosa Zheng and Chengshan Xiao, “Simulation models with correct statistical properties for Rayleigh fading channels”

    Best regards,
    Fjolla

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