本文選題：F-OFDM + OFDM��； 參考：《西南交通大學(xué)》2017年碩士論文

【摘要】：隨著IMT-2020(5G)推進(jìn)組對(duì)未來(lái)通信需求的明確,多種應(yīng)用場(chǎng)景和業(yè)務(wù)需求給物理層波形的設(shè)計(jì)帶來(lái)了新的挑戰(zhàn)。2015年,華為在正交頻分復(fù)用(OFDM)技術(shù)的基礎(chǔ)上提出了基于子帶濾波的正交頻分復(fù)用(Filtered-OFDM,F-OFDM)技術(shù),其通過(guò)子帶濾波降低頻譜帶外泄露,各子帶根據(jù)具體的業(yè)務(wù)需求靈活配置波形參數(shù),從而實(shí)現(xiàn)了靈活自適應(yīng)的空口技術(shù)。F-OFDM作為一種新興的多載波技術(shù),對(duì)頻偏造成的載波間干擾(Inter-Carrier Interference,ICI)較為敏感。因此,有必要在當(dāng)前F-OFDM研究現(xiàn)狀的基礎(chǔ)上,利用OFDM頻偏估計(jì)算法來(lái)實(shí)現(xiàn)F-OFDM系統(tǒng)的頻偏估計(jì),以降低頻偏對(duì)系統(tǒng)性能的影響。首先,本文系統(tǒng)地分析了無(wú)線信道的小尺度衰落特性以及頻偏對(duì)OFDM系統(tǒng)的影響,并深入研究了現(xiàn)有的OFDM頻偏估計(jì)算法,從理論推導(dǎo)和MATLAB仿真兩個(gè)方面對(duì)不同算法的估計(jì)性能進(jìn)行了驗(yàn)證分析。其次,根據(jù)不同子帶的F-OFDM符號(hào)能夠在時(shí)域共存而在頻域分離,對(duì)子帶資源分配和子載波映射進(jìn)行了研究,并通過(guò)MATLAB仿真比較了不同子載波間隔和不同帶寬對(duì)子帶性能的影響,結(jié)果表明子載波間隔越大,多普勒頻移對(duì)子帶性能的影響越小。另外,驗(yàn)證了濾波操作能夠有效地降低子帶頻譜帶外泄露,從而使不同子帶設(shè)置極低的保護(hù)間隔就能很好的抑制相鄰子帶間的干擾。最后,結(jié)合OFDM頻偏估計(jì)算法與F-OFDM的系統(tǒng)特性,分析比較了 CP相關(guān)性算法、改進(jìn)的CP算法、Moose算法和Classen算法在不同子帶的估計(jì)精度。通過(guò)仿真分析可得:當(dāng)子帶的子載波間隔較大時(shí),多普勒頻移對(duì)子帶性能的影響較小,且每個(gè)F-OFDM符號(hào)中插入的CP采樣點(diǎn)較多,因此,子載波間隔較大的子帶適合利用基于CP的頻偏估計(jì)算法。當(dāng)子帶的子載波間隔較小時(shí),多普勒頻移對(duì)子帶性能影響較大,并且子帶的符號(hào)長(zhǎng)度較長(zhǎng)以及插入的導(dǎo)頻序列較多,因此,子載波間隔較小的子帶適合利用估計(jì)精度較高的數(shù)據(jù)輔助頻偏估計(jì)算法。此外,在系統(tǒng)帶寬與采樣率保持一致的前提下,仿真比較了雙子帶F-OFDM系統(tǒng)與OFDM系統(tǒng)利用同一算法進(jìn)行頻偏補(bǔ)償后的誤碼率。由于子帶能夠靈活設(shè)置波形參數(shù)以及頻偏算法無(wú)法徹底消除頻偏引起的ICI,使得F-OFDM系統(tǒng)的誤碼率要低于子載波間隔較小的OFDM系統(tǒng)的誤碼率,高于子載波間隔較大的OFDM系統(tǒng)的誤碼率,體現(xiàn)了 F-OFDM系統(tǒng)通過(guò)靈活配置波形參數(shù)能夠有效的降低無(wú)線信道對(duì)系統(tǒng)性能的影響。
[Abstract]:With the IMT-2020 5G) propulsion team defining future communications requirements, multiple application scenarios and business requirements pose new challenges to the design of physical layer waveforms. Based on orthogonal Frequency Division Multiplexing (OFDM) technology, Huawei proposes a sub-band filter based orthogonal Frequency Division Multiplexing (OFDM) technique, which can reduce the leakage of spectrum out of band by subband filter, and configure waveform parameters flexibly according to specific business requirements. As a new multi-carrier technology, F-OFDM is sensitive to Inter-Carrier interference (ICI) caused by frequency offset. Therefore, it is necessary to use OFDM frequency offset estimation algorithm to realize the frequency offset estimation of F-OFDM system on the basis of the current research status of F-OFDM, so as to reduce the influence of frequency offset on the performance of F-OFDM system. Firstly, the small scale fading characteristics of wireless channel and the influence of frequency offset on OFDM system are systematically analyzed, and the existing OFDM frequency offset estimation algorithms are deeply studied. The estimation performance of different algorithms is verified and analyzed in terms of theoretical derivation and MATLAB simulation. Secondly, according to the F-OFDM symbols of different subbands can coexist in time domain and separate in frequency domain, the sub-band resource allocation and sub-carrier mapping are studied, and the effects of different sub-carrier spacing and different bandwidth on sub-band performance are compared by MATLAB simulation. The results show that the larger the subcarrier spacing, the smaller the influence of Doppler shift on subband performance. In addition, it is proved that the filtering operation can effectively reduce the out-of-band leakage of the sub-band spectrum, so that the interference between adjacent sub-bands can be suppressed very well by setting very low protection interval of different sub-bands. Finally, combining the characteristics of OFDM frequency offset estimation algorithm and F-OFDM system, the estimation accuracy of CP correlation algorithm, improved CP algorithm moose algorithm and Classen algorithm in different sub-bands are analyzed and compared. The simulation results show that the Doppler frequency shift has little effect on the performance of the sub-band when the sub-carrier spacing of the sub-band is large, and there are more CP sampling points inserted in each F-OFDM symbol. The frequency offset estimation algorithm based on CP is suitable for subbands with large subcarrier spacing. When the subcarrier spacing of the subband is small, the Doppler frequency shift has a great influence on the performance of the subband, and the symbol length of the sub-band is longer and the pilot sequence is more inserted. The subbands with small subcarrier spacing are suitable to use the data-aided frequency offset estimation algorithm with higher estimation accuracy. In addition, on the premise that the system bandwidth is consistent with the sampling rate, the bit error rate (BER) of the dual-subband F-OFDM system is compared with that of the OFDM system using the same frequency offset compensation algorithm. Because the subband can set the waveform parameters flexibly and the frequency offset algorithm can not completely eliminate the ICI caused by the frequency offset, the bit error rate of the F-OFDM system is lower than that of the OFDM system with small sub-carrier spacing. The BER of OFDM system is higher than that of OFDM system with large sub-carrier spacing, which shows that F-OFDM system can effectively reduce the influence of wireless channel on system performance by configuring waveform parameters flexibly.
【學(xué)位授予單位】：西南交通大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TN929.53

【參考文獻(xiàn)】

相關(guān)期刊論文 前5條

1 Rahat Ullah;Bo Liu;Qi Zhang;Yousaf Khan;Amjad Ali;Qinghua Tian;Feng Tian;M.Saad Khan;Tabinda Salam;Sibghat Ullah;Lijia Zhang;Xiangjun Xin;;Colorless WDM-PON Using Single Side Band Carrier Suppressed Signals Mitigating Carrier Rayleigh Backscattering[J];中國(guó)通信;2016年12期

2 楊凡;曾孝平;周繼華;阮定良;張波;吳華;;F-OFDM系統(tǒng)的基帶技術(shù)研究[J];重慶理工大學(xué)學(xué)報(bào)(自然科學(xué));2016年09期

3 高亞楠;楊濤;胡波;;5G系統(tǒng)中F-OFDM算法設(shè)計(jì)[J];電子技術(shù)應(yīng)用;2016年07期

4 虞云梅;霍麗麗;;OFDM系統(tǒng)中基于循環(huán)前綴的頻偏估計(jì)算法[J];軟件;2016年02期

5 禹永植;張興周;孫會(huì)楠;;OFDM系統(tǒng)中的一種有效頻偏估計(jì)算法[J];系統(tǒng)仿真學(xué)報(bào);2008年14期

相關(guān)博士學(xué)位論文 前1條

1 周恩;多徑信道下OFDM系統(tǒng)同步算法研究[D];北京郵電大學(xué);2006年

，

本文編號(hào)：2012037