Xiao Wen Li

Research on TD-LTE Downlink Packet Scheduling

In order to solve the limitations of classical packet scheduling architecture in TD-LTE, the TD-LTE downlink packet scheduling was studied and a architecture of downlink packet scheduling for TD-LTE is designed. The packet scheduling architecture was built and three classic scheduling algorithms were simulated in this architecture by Matlab. The simulation results show that the packet scheduling architecture can be applied to scheduling algorithms with different purposes and verify the performances of throughput and fairness of these three scheduling algorithms.

Research on RACH Signal Detection Algorithm in TD-LTE System

In TD-LTE system, RACH (Random Access Channel) process is an important process for gaining time-frequency resource of uplink. Through the research on RACH signal detection, a low-complexity implementation approach is proposed in this paper. After research and analysis of RACH signal time domain detection algorithm and RACH signal circulate correlation algorithm based on Fast Fourier Transform (FFT), According to the Zadoff-Chu (ZC) sequence character, RACH signal circulate correlation on detection algorithm based on frequency domain ZC is proposed in this paper .Combined with different algorithm, the algorithm is proposed in this paper can rapid and effective realize RACH signal detection.

Research on the Carrier Aggregation Application in the Blind Detection of PDCCH

This article expounds the latest developments of key technology about carrier aggregation of LTE-A, and introduces cross carrier scheduling. Then it mainly studies the control signaling, reconfiguration message sent from upper layers defined by 3GPP protocol, and Physical Downlink Control Channel (PDCCH) blind decoding method which supports cross carrier scheduling. Finally, with correct simulation results, it shows that the method meets the requirement of 3GPP, and provides a theoretical basis for realizing detection of PDCCH in LTE-A system.

Realization and Simulation of High Speed Flexible Transmission System between FPGA Chips Based on SRIO

This paper issued a new scheme that passing the configuration information of SRIO to FPGA through EMIF interface, so that two FPGAs can transfer data to each other dynamically for different ways of data interaction. In a word, this paper provides a flexible high-speed transmission scheme for the TD-LTE RF conformance test instrument development.

DSP Realization of De-Turbo Code Rate Matching in LTE System

This paper firstly describes the basic principle of turbo rate matching.on the basic .the paper introduces a rate de-matching program of the available DSP implementation.compared to the conventional algorithm .the program reduces the processing time and the need to handle the amount of data and improves the processing efficiency.it has been implemented in TMS320C6455and the application running in CCS3.3, MATLAB verifies that this scheme is feasible and effective.

Realization of Primitive Trace in TD-LTE RF Conformance Testing Instrument

In order to satisfy the requirement of reliability in the TD-LTE RF Conformance Testing Instrument, a method to achieve the trace of primitive of TD-LTE based on embedded system is imposed. According to the feature of the long term evolution (LTE) system, it highlights the details of primitive tracing through DMA and UART. The primitive is strongly real-time to achieve QoS in LTE. Verified multiple times this design achieves the primitive trace in LTE as well as meets the requirement of hardware platform in TD-LTE RF Conformance Testing Instrument.

The Research on PRACH Receiver and the DSP Implementation

In LTE system, random access plays an important role in both uplink time adjustment and initial access of UE. This paper analyzes the theory of the related signal detection and the correlation calculation, and proposes a method to detect the received sequence in the receiver. And at last, it presents the implementation on DSP including the baseband signal processing module, Local frequency domain ZC sequence generation module and Correlation calculation module. In a word, it provides a solution for implement the PRACH receiver on hardware.

LTE-A System Downlink HARQ System-Level Design and Simulation

Hybrid automatic retransmission technology for reducing the error rate and the rate of data transmission system play an important role in the LTE-A system, so designing A good kind of HARQ transmission mechanisms and processes is necessary for system operation, which has guidance for network and terminal. In this paper the main research is the downlink HARQ. Based on the interface between the layers, the paper designs a flow chart for the HARQ, finally, makes a brief introduction of the SDL and TTCN tools and its work principles, based on the previous design and development of code, takes the process of data transmission for instance, by the C code embedded in the SDL, gets the software implementation, and by use of the TTCN tools, makes a conduction of test case, and then by the co-simulation of SDL and TTCN, gets the MSC diagram of the related process, and verify the correction of the previous designed by the analysis of the MSC.

Design of RF Control System Based on TD-LTE

This paper explains a method to design a RF system using FPGA and DSP. After DSP sending RF circuit controlling words to FPGA through its EMIF interface, FPGA then imitate the behavior of the EMIF interface to receive these information. The received data will be used to configure the RF circuit correctly. Data information will be sent to FPGA in the same way by DSP when RF circuit is configured completely, Then FPGA sends baseband data to RF circuit which convert it to RF signal. Through simulation, synthesis, plate level verification, and online debugging, this design has realized the correct RF control system, which has been used in the development of RF conformance test instruments.

The Design and Realization of Packet Data Security in LTE-A

In the wireless access technology system, reliable and more efficient security algorithm is important to guarantee high-speed data transmission of LTE. In the development process of LTE-A Radio Frequency Conformance Test System, we designed a detailed security process in PDCP ( Packet Data Convergence Protocol ) and realized it through encryption algorithm and Integrity algorithm. This paper adopts SDL and TTCN to test the security process of PDCP.And we applied it to LTE-A system successfully.