# US 2013/0155867 A1 · Scalable architecture for long term evolution (lte) multiple user equipment (multi-ue) simulation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0155867 A1 - Document ID: US20130155867A1 - Status: Published application - Kind: A1 - Application number: 13/429,384 - Filed: 2012-03-25 - Published: 2013-06-20 - Earliest claimed: 2011-12-14 - Assignees: Ixia - Inventors: Ramanathan Asokan; Kalyan Sundhar - Web page: https://patentgrep.com/patent/US20130155867A1 ## CPC - H04W 24/06: Testing, {supervising or monitoring} using simulated traffic - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A system for scalably simulating multiple LTE UE devices includes an LTE multi-UE simulator. The simulator includes a common public radio interface (CPRI) module for receiving downlink data from an evolved node B (eNode B) under test and a downlink signal chain processing module including a common section for performing UE agnostic processing of the downlink data and a UE specific section for performing UE specific processing of the downlink data. The simulator further includes a control digital signal processor (DSP) for receiving the downlink data from the common section of the downlink signal chain processing module, for processing downlink data to obtain control information, and for forwarding the control information to the downlink signal chain processing module. The UE specific portion of the downlink signal chain processing module performs the UE specific processing using the control information. ## Claims ### Claim 1 A system for scalably simulating multiple long term evolution (LTE) user equipment (UE) devices, the system comprising: an LTE multi-UE simulator comprising: a common public radio interface (CPRI) module for receiving downlink data from an evolved node B (eNode B) under test; a downlink signal chain processing module including a common section for performing UE agnostic processing of the downlink data and a UE specific section for performing UE specific processing of the downlink data; and a control digital signal processor (DSP) for receiving the downlink data from the common section of the downlink signal chain processing module, for processing the downlink data to obtain control information, and for forwarding the control information to the downlink signal chain processing module, wherein the UE specific portion performs the UE specific processing using the control information. ### Claim 2 (depends on 1) The system of claim 1 wherein the common section includes a bus interface for receiving the downlink data from the CPRI module, a cyclic prefix removal block for removing a cyclic prefix from the downlink data, a symbol truncation block for truncating symbols in the downlink data, a subcarrier demapper for removing a subcarrier signal from the downlink data, and a channel estimation and equalization block for performing channel estimation and equalization of a signal carrying the downlink data. ### Claim 3 (depends on 1) The system of claim 1 wherein the UE specific section includes a plurality of control signal processing blocks to process control signals present in the downlink data, an interface for communicating with the control DSP, a code block segmentation and scheduler for segmenting the downlink data into code blocks, and a rate dematcher for deinterleaving the downlink data in the code blocks. ### Claim 4 (depends on 1) The system of claim 1 wherein the LTE multi-UE traffic simulator includes a downlink channel decoder for receiving the downlink data from the rate downlink signal chain processing module and for performing decision directed routing at the downlink channel decoder for sending a first portion of the downlink data to the control DSP and for sending a second portion of the downlink data to a radio link control (RLC) and medium access control (MAC) module for further processing. ### Claim 5 (depends on 4) The system of claim 4 wherein the first portion of the downlink data includes random access response (RAR) data and wherein the second portion of the downlink data includes RLC/MAC data other than the RAR data. ### Claim 6 (depends on 5) The system of claim 5 wherein the control DSP imbeds a descriptor in the control data returned to the downlink signal chain processing module, wherein the downlink processing module forwards the descriptor to the downlink channel decoder, and wherein the downlink channel decoder uses the descriptor in identifying the RAR data and the RLC/MAC data other than the RAR data. ### Claim 7 (depends on 4) The system of claim 4 wherein the downlink channel decoder comprises a Turbo decoder. ### Claim 8 (depends on 1) The system of claim 1 wherein the UE specific section is configured to process downlink data for a plurality of different channels corresponding to a plurality of UEs being simulated by the LTE multi-UE traffic simulator. ### Claim 9 (depends on 5) The system of claim 5 wherein the control DSP processes the RAR data to extract uplink grant information, wherein the LTE multi-UE traffic simulator comprises an uplink DSP for receiving uplink grant information from the control DSP and using the uplink grant information to generate uplink transport blocks, and wherein the LTE multi-UE simulator further includes an uplink signal chain processing module for receiving the uplink transport blocks and sending the uplink transport blocks to the CPRI module. ### Claim 10 (depends on 9) The system of claim 9 wherein the uplink signal chain processing module includes a UE-specific section for performing UE-specific processing of the uplink transport blocks and a UE-agnostic section for performing UE-agnostic processing of the uplink transport blocks. ### Claim 11 (depends on 9) The system of claim 9 wherein the uplink and downlink signal chain processing modules are implemented using separate field programmable gate arrays (FPGAs). ### Claim 12 (depends on 1) The system of claim 1 wherein the control DSP is configured to process the downlink data and return the control data to the downlink signal chain processing module within 400 microseconds. ### Claim 13 A method for scalably simulating multiple long term evolution (LTE) user equipment (UE) devices, the method comprising: at an LTE multi-UE simulator: at a common public radio interface (CPRI) module, receiving downlink data from an evolved node B (eNode B) under test; at a downlink signal chain processing module including a common section and a UE specific section performing, in the common section, UE agnostic processing of the downlink data and performing, in the UE specific section, UE specific processing of the downlink data; and at a control digital signal processor (DSP), receiving the downlink data from the common section of the downlink module, processing the downlink data to obtain control information, and forwarding the control information to the downlink signal chain processing module, wherein the UE-specific portion performs the UE-specific processing using the control information. ### Claim 14 (depends on 13) The method of claim 13 wherein the common section includes a bus interface for receiving the downlink data from the CPRI module, a cyclic data, and a channel estimation and equalization block for performing channel estimation and equalization of a signal carrying the downlink data. ### Claim 15 (depends on 13) The method of claim 13 wherein the UE specific section includes a plurality of control signal processing blocks to process control signals present in the downlink data, an interface for communicating with the control DSP, a code block segmentation and scheduler for segmenting the ### Claim 16 (depends on 13) The method of claim 13 wherein the LTE multi-UE traffic simulator comprises a downlink channel decoder for receiving the downlink data from the downlink signal chain processing module and for performing decision directed routing at the downlink channel decoder for sending a first portion of the downlink data to the control DSP and for sending a second portion of the downlink data to a radio link control (RLC) and medium access control (MAC) module for further processing. ### Claim 17 (depends on 13) The method of claim 13 wherein the first portion of the downlink data includes random access response (RAR) data and wherein the second portion of the downlink data includes RLC/MAC data other than the RAR data. ### Claim 18 (depends on 17) The method of claim 17 wherein the control DSP imbeds a descriptor in the control data returned to the downlink signal chain processing module, wherein the downlink signal chain processing module forwards the descriptor to the downlink channel decoder, and wherein the downlink channel decoder uses the descriptor in identifying the RAR data and the RLC/MAC data other than the RAR data. ### Claim 19 (depends on 16) The method of claim 16 wherein the downlink channel decoder comprises a Turbo decoder. ### Claim 20 (depends on 13) The method of claim 13 wherein the UE specific section is configured to process downlink data for a plurality of different channels corresponding to a plurality of UEs being simulated by the LTE multi-UE traffic simulator. ### Claim 21 (depends on 17) The method of claim 17 wherein the control DSP processes the RAR data to extract uplink grant information, wherein the LTE multi-UE traffic simulator comprises an uplink DSP for receiving uplink grant information from the control DSP and using the uplink grant information to generate uplink transport blocks, and wherein the LTE multi-UE simulator further includes an uplink signal chain processing module for receiving the uplink transport blocks and sending the uplink transport blocks to the CPRI module. ### Claim 22 (depends on 21) The method of claim 21 wherein the uplink signal chain processing module includes a UE-specific section for performing UE-specific processing of the uplink transport blocks and a UE-agnostic section for performing UE-agnostic processing of the uplink transport blocks. ### Claim 23 (depends on 21) The method of claim 21 wherein the uplink and downlink signal chain processing modules are implemented using separate field programmable gate arrays (FPGAs). ### Claim 24 (depends on 13) The method of claim 13 wherein the control DSP is configured to process the downlink data and return the control data to the downlink signal chain processing module within 400 microseconds. ### Claim 25 A non-transitory computer readable medium having stored thereon executable instructions that when executed by the processor of a computer controls the computer to perform steps comprising: at an LTE multi-UE simulator: at a common public radio interface (CPRI) module, receiving downlink data from an evolved node B (eNode B) under test; at a downlink signal chain processing module including a common section and a UE specific section performing, in the common section, UE agnostic processing of the downlink data and performing, in the UE specific section, UE specific processing of the downlink data; and at a control digital signal processor (DSP), receiving the downlink data from the common section of the downlink module, processing the downlink data to obtain control information, and forwarding the control information to the downlink module, wherein the UE specific portion performs the UE specific processing using the control information.