Ici Suppression Method And Pdcch In 3 Gpp Lte System Performance Simulation

Single carrier frequency division multiple access (SC-FDMA) has low Peak toAverage Power Ratio (PAPR) feature, it has been selected as the uplink transmissiontechnology of3GPP long term evolution (LTE). However, SC-FDMA is very sensitiveto carrier frequency offect (CFO), which leads to inter-carrier interference (ICI). In theuplink of multi-user system, ICI is composed of symbol interference (SI) in a singleuser and multiple-user interference (MUI), system performance is seriously effected,especially in the high-speed mobile environment, CFO is more serious due to the effectof high Doppler shift, leads to significant performance degradation.On the other hand, LTE physical downlink control channel (PDCCH) carriesscheduling assignments and other control information. The performance of otherphysical channels will be directly affected by PDCCH. Therefore, this dissertationstudies the ICI suppression technique in the LTE uplink and evaluates the LTE PDCCHperformance, specific studies are outlined as follows:Chapter1summarizes the transmission technologies of LTE and physical layertechnical specification, and points the main study contents of this dissertation.Chapter2studies the ICI suppression technique in the LTE uplink. Firstly,analyzes the importance of ICI suppression in LTE uplink, summarizes the typicalexisting methods of suppressing ICI and shows their limitations. Secondly, analyzesthe performance of uplink SC-FDMA in the presence of CFOs, and shows numericalresults to verify the derived results. Based on the theoretical analysis, proposes twonovel ICI suppression schemes. In the first prosposed scheme, all the users are dividedinto large CFO users set and small CFO users set, the other proposed scheme is basedon sorting users by their average signal-to-interference ratio (SIR). Lastly, shows thesimulation results of the proposed schemes in the3GPP EVA channel model.Simulation resultes show that compared to the conventional schemes, the firstproposed scheme obtains a better tradeoff between computational complexity andsystem performance in terms of bit error rate (BER), the second proposed scheme obtains3dB gain.Chapter3studies the ICI suppression technique of LTE uplink in the high-speedmobile environment. The proposed ICI suppression scheme based on sorting SIR isapplied in the high-speed mobile environment to verify its validity. Systemperformance is further improved by increasing iterative times of the schemes, orincreasing the number of the receiving antennas.Chapter4studies LTE PDCCH link level performance simulation. Firstly,describes the transmission and receiving process of PDCCH. Secondly, constructs thePDCCH link level simulation platform. Lastly, simulates the performance of PDCCH,evaluates the single-cell single-user and multi-cell edge-user’s PDCCH performance interms of block errorrate (BLER) in different CCE aggregation levels and differentchannel models.Chapter5summarizes the whole article, and investigates the possible futuredirections.