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Intercarrier Interference Self-Cancellation Scheme forOFDM Mobile Communication Systems.

Intercarrier Interference Self-Cancellation Scheme for OFDM Mobile Communication Systems

Yuping Zhao and Sven-Gustav H?ggman

Abstract—For orthogonal frequency-division multiplexing (OFDM)communication systems,the frequency offsets in mobile radio channels distort the orthogonality between subcarriers resulting in intercarrier interference(ICI).This paper studies an efficient ICI cancellation method termed ICI self-cancellation scheme.The scheme works in two very simple steps.At the transmitter side,one data symbol is modulated onto a group of adjacent subcarriers with a group of weighting coefficients.The weighting coefficients are designed so that the ICI caused by the channel frequency errors can be minimized.At the receiver side, by linearly combining the received signals on these subcarriers with proposed coefficients,the residual ICI contained in the received signals can then be further reduced.The carrier-to-inter-ference power ratio(CIR)can be increased by15and30dB when the group size is two or three,respectively,for a channel with a constant frequency offset.Although the redundant modulation causes a reduction in bandwidth efficiency,it can be compensated, for example,by using larger signal alphabet sizes.Simulations show that OFDM systems using the proposed ICI self-cancellation scheme perform much better than standard systems while having the same bandwidth efficiency in multipath mobile radio channels with large Doppler frequencies.

Index Terms—ICI self-cancellation,intercarrier interference, multicarrier modulation,OFDM.

I.I NTRODUCTION

O RTHOGONAL frequency-division multiplexing (OFDM)communication systems[1],[2]require precise frequency synchronization,since otherwise intercar-rier interference(ICI)will occur.Currently,three different approaches for reducing ICI have been developed including frequency-domain equalization[3],[4],time-domain win-dowing[5],[6],and the ICI self-cancellation scheme[7],[8]. This paper concentrates on the further development of the third method.

The ICI self-cancellation scheme is a very simple way for suppressing ICI in OFDM.The main idea is to modulate one data symbol onto a group of subcarriers with predefined weighting coefficients.By doing so,the ICI signals generated

Paper approved by N.C.Beaulieu,the Editor for Wireless Communication Theory of the IEEE Communications Society.Manuscript received June25, 1997;revised October2,1998.This work carried out at the Communications Laboratory,Department of Electrical Engineering,Helsinki University of Tech-nology and supported by the Graduate School of Electronics,Telecommunica-tion and Automation in Finland.

Y.Zhao was with the Communications Laboratory,Helsinki University of Technology,02150Espoo,Finland.She is now with the Depart-ment of Electronics,Peking University,Beijing100871,China(e-mail: yuping.zhao@https://www.wendangku.net/doc/933227905.html,).

S.-G.H?ggman is with the Communications Laboratory,Helsinki University of Technology,02150Espoo,Finland.

Publisher Item Identifier S0090-6778(01)05768-3.within a group can be“self-cancelled”each other.After the works given in[7]and[8],the further discussions of the ICI self-cancellation scheme are presented in[9]and[10], where the scheme is also called polynomial cancellation coding(PCC).1In the previous studies,the emphasis has been put on the mechanism analysis of the scheme.The works presented in this paper concentrate on a quantitative ICI power analysis of the ICI self-cancellation scheme,which has not been studied previously.The average carrier-to-interference power ratio(CIR)[11]is used as the ICI level indicator,and a theoretical CIR expression is derived for the proposed scheme. Furthermore,simulation results under different conditions are presented to demonstrate the reliability and advantage of the ICI self-cancellation scheme.

II.ICI M ECHANISM OF S TANDARD OFDM S YSTEMS

In an OFDM communication system,assuming the channel frequency offset normalized by the subcarrier separation

can be written

(1)

where

-ary phase-shift keying(PSK),for ex-ample)for

the

is defined as the ICI coefficient between th subcarriers,which can be expressed

.The second term is the ICI compo-nents.Fig.1gives an example of

the

and

and. It is evident that

(a)(b)

(c)

Fig.1.An example of S(l0k)for N=16;l=0.(a)Amplitude of S(l0k).(b)Real part of S(l0k).(c)Imaginary part of S(l0k).

noise is omitted.The desired received signal power on the

(4)

It is assumed that the transmitted data have zero mean and

are statistically independent,therefore,the CIR expression for

subcarrier

,where

ZHAO AND H?GGMAN:ICI SELF-CANCELLATION SCHEME FOR OFDM MOBILE COMMUNICATION SYSTEMS 1187

Equation (5)suggests that the CIR is a function

.Anal-ysis shows that the CIR,for a

given

ap-proximately.

III.ICI C ANCELLING M ODULATION

The conclusion in Section II implies that it is impossible to reduce ICI unless

the

values can be obtained by in-creasing the subcarrier separation.Consequently,the bandwidth efficiency will be reduced since the time-domain symbol length is reduced and,therefore,the guard interval will take a relatively larger portion of the useful signal.

It has been shown in Fig.1that both real and imaginary parts of the ICI coefficient are gradually changed with respect to the

subcarrier index.For the majority of

values,the difference

between

is modulated onto two adjacent

subcarriers is a complex data,then the ICI signals gener-ated by the

subcarrier

becomes

(6)

and on

subcarrier

(7)

In such a case,the ICI coefficient is denoted

(8)

The comparison

between and

values,it is found

that

.In addition,the

summation in (6)only takes even

(l 0k )j and j S (l 0k )j ;N =

64.

IV .ICI C ANCELLING D EMODULATION

By using the ICI cancelling modulation,each pair of subcar-riers,in fact,transmit only one data symbol.The signal redun-dancy makes it possible to improve the system performance at the receiver side.In considering a further reduction of ICI,a so-called ICI cancelling demodulation scheme is analyzed here.The demodulation is suggested to work in such a way that each

signal at

the

denotes even number)is multiplied by “

th subcarrier.Then the resultant data sequence is used for making symbol decision.It can be represented

(9)

The corresponding ICI coefficient then

becomes .Notice the logarithmic scale on the ver-tical axis.For the majority of

values,

1188IEEE TRANSACTIONS ON COMMUNICATIONS,VOL.49,NO.7,JULY

2001

Fig.4.CIR improvement using ICI self-cancellation scheme. whereas the noise level is proportional

(11)

Fig.4shows the theoretical CIR curve calculated by(11)to-

gether with simulation results.As a reference,the CIR of a stan-

dard OFDM system using(5)is also shown.Such an ICI cancel-

lation scheme gives more than15-dB CIR improvement in the

range.Especially for small to medium frequency

offsets in the

range,the CIR improvement can

reach17dB.

Due to the repetition coding,the bandwidth efficiency of the

ICI self-cancellation scheme is reduced by half.To fulfill the

demanded bandwidth efficiency,it is natural to use a larger

signal alphabet size.For example,using4PSK modulation

together with the ICI self-cancellation scheme can provide

the same bandwidth efficiency as standard OFDM systems

(1bit/Hz/s).When the channel frequency offset is small,the

use of a larger signal alphabet size might increase the system

bit-error rate(BER)compared to a smaller alphabet size

[13].However,for medium to large channel frequency offsets

(

subcarriers,the data symbol is multiplied with a co-

efficient vector of

length

denotes one

subcarrier delay in the discrete frequency domain.

In general for a group

length

term in

polynomial can be represented

becomes(12),shown at the

bottom of the page.

Fig.5shows the CIR comparison

for.By

using

,about30-dB CIR improvement can be found in the

range

,compared with a standard OFDM

system

(12)

ZHAO AND H?GGMAN:ICI SELF-CANCELLATION SCHEME FOR OFDM MOBILE COMMUNICATION SYSTEMS

1189

Fig.6.Simulation block diagram of the proposed

system.

Fig.7.BER versus E of two systems for different "values.2)System 2(Sys.2):4PSK modulation OFDM system with ICI self-cancellation.

The simulation block diagram of the proposed system (Sys.2)is shown in Fig.6,while Sys.1can be obtained by simply re-moving the “ICI cancelling modulation”and “ICI cancelling de-modulation”blocks.The bandwidth efficiency is 1bit/Hz/s for both systems.The same values

,the BER of Sys.1is lower than that of

Sys.2.This is because differential BPSK modulation (Sys.1)performs better than differential 4PSK (Sys.2)in the

AWGN

Fig.8.BER comparison for typical urban area channel model.

channel [13].Increasing the frequency offset

),the BER of the standard OFDM system (Sys.1)

increases significantly,while the BER of the proposed system

1190IEEE TRANSACTIONS ON COMMUNICATIONS,VOL.49,NO.7,JULY2001

Fig.9.BER comparison for rural area channel model.

Fig.10.BER of ICI self-cancellation scheme and error correction coding.

(Sys.2)only increases slightly,compared to the situation where

ZHAO AND H?GGMAN:ICI SELF-CANCELLATION SCHEME FOR OFDM MOBILE COMMUNICATION SYSTEMS

1191

Yuping Zhao received the B.S.and M.S.degrees

in electrical engineering from Northern Jiaotong

University,Beijing,China,in1983and1986,

respectively.She received the Ph.D.and Doctor

of Science degrees in wireless communications

from Helsinki University of Technology,Helsinki,

Finland,in1997and1999,respectively.

From1986to1993,she was a System Engineer for

telecommunication companies in China and Japan.

From1995to1997,she worked in OFDM commu-

nication systems at the Helsinki University of Tech-nology,Helsinki,Finland.From1997to2000,she was with Nokia Research Center in the field of radio resource management for wireless mobile communi-cation networks.Currently,she is an Associate Professor in the Department of Electronics,Peking University,Beijing,China.Her research interests include coding and modulation techniques,the performance analysis of mobile radio channels,and the radio resource management of wireless mobile

networks.

Sven-Gustav H?ggman was born in Pietarsaari,Fin-

land,in1943.He received the master’s,licentiate,

and doctoral degrees in communications engineering

from the Helsinki University of Technology(HUT),

Helsinki,Finland,in1970,1979,and1991,respec-

tively.

He has been with the Communications Laboratory

at HUT since1970,until1991in various teaching

and research positions,since1991as Associate Pro-

fessor and since1998as Professor in Radio Commu-

nications.His research activities have included ter-restrial radio relay system planning and microwave LOS-channel measurement and modeling.Presently,he is conducting research on mobile radio channel measurement and modeling,radio interface techniques,cellular radio network planning,and radio resource management methods.

Prof.H?ggman is a member of The Engineering Society in Finland TFiF and the Association of Electrical Engineers in Finland.

2018高三英语常用动词短语搭配(完美版)

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英语介词与形容词动词搭配

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初中英语常见动词短语归纳讲解学习

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常见短语搭配

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动词与介词搭配

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g．According to the Bible，we are all descended from Adam． h．This picture is a copy from Raphael．i．Thousands of English words are derived from/derive from Latin．quote from the classics（引自古文），draw water from a well（从井里汲水），drink from a river（临河而饮），draw conclusions from the evi－deuce（由证据中取得结论）。 ①originate（来自），当来源是事物时，用from或in皆可；当来源为人时，用from 或with皆可。

RNA干扰(RNA interference, RNAi)

RNA干扰(RNA interference，RNAi)是近年来发现的研究生物体基因表达、调控与功能的一项崭新技术，它利用了由小干扰RNA(small interfering RNA，siRNA)引起的生物细胞内同源基因的特异性沉默(silencing)现象，其本质是siRNA与对应的mRNA特异结合、降解，从而阻止mRNA的翻译。RNAi是生物进化的结果，是生物体对病毒基因等外源核酸侵入的一种保护性反应。它普遍存在于各种生物，具有抗病毒、稳定转座子及监控异常表达ｍRNA 的生物学功能。RNA干扰现象不仅能提供一种经济、快捷、高效的抑制基因表达的技术手段，而且有可能在基因功能测定，基因治疗等方面开辟一条新思路。 1 RNAi的历史背景 20世纪20年代，人们发现，植物受到野生型病毒感染后，能产生对另一种亲缘关系相近的病毒的抵抗力。而真正发现双链RNA(dsRNA)能引起基因沉默现象，则在1995年。当时，Guo和Kemphues用反义RNA技术阻断秀丽新小杆线虫(C.elegans)中parl基因的表达时发现反义RNA具有抑制该基因表达的功能，同时正义RNA也同样出现了类似的抑制效应，实验表明正义RNA和反义RNA均能阻抑基因功能表达，而且两者的作用是相互独立的，机制也各不相同。1998年，Fire和Mello等人首次发现dsRNA能够特异地抑制C.elegans中的纹状肌细胞unc-22基因的表达，结果发现dsRNA所引起的基因沉默效应要比单单应用反义RNA或正义RNA强十几倍。而且注射入C.elegans的性腺后，在其第一子代中也诱导出了同样基因的抑制现象，说明在原核生物中，RNAi具有可遗传性。他们将这一现象称为RNAi。因为RNAi作用发生在转录后水平，所以又被称为转录后基因沉默(PTGS)或共抑制。此后，又在果蝇、锥虫、涡虫、无脊椎动物、脊椎动物、植物、真菌、斑马鱼及哺乳动物等真核生物中发现了RNAi现象。不同领域中的发现促使人们思考它们之间的可能联系。RNAi 在果蝇中得到证实的同时，发现转座子翻转移位可启动RNAi，而转座子翻转移位所造成的同源基因沉默很似植物中的共抑制；在线饱霉实验中，发现PTGS过程中所必须的蛋白QDE1与RNA依赖的RNA聚合酶(RdRp)同源，提示PTGS过程中可能涉及到RNA复制及调节作用。同样在植物韧皮部注射dsRNA可遍及扩散到整个植株体产生RNAi；更有趣的是，把线虫浸润到含有dsRNA液体中或喂养表达dsRNA的工程菌也可以诱发RNAi。这种存在揭示了RNAi很可能是出现于生命进化的早期阶段。随着研究的不断深入，RNAi的机制正在被逐步阐明，而同时作为功能基因组研究领域中的有力工具，RNAi也越来越为人们所重视。 2 RNAi的作用机理目前对RNAi的作用机理尚不清楚，RNAi是由dsRNA诱导的多步骤、多因素参与的过程，属于基因转录后调控，其中需要ATP的参与。通常认为dsRNA由核酸内切酶(RNA se Ⅲ)切割成21～23bp的siRNA (在果蝇RNA se Ⅲ被称为dicer)，siRNA再与体内一些酶(包括内切酶、外切酶、螺旋酶)结合形成RNA诱导的沉默复合物RISC，然后RISC再特异性地与ｍRNA的同源区结合，通过酶的作用使ｍRNA降解，而产生基因沉默。靶ｍRNA被破坏后，RISC还可以再作用于其它靶分子。siRNA还具有低分子质量、低浓度、沉默信号可在细胞间传递甚至传播至整个有机体以及可遗传等特点。而大于30bp的dsRNA可引起机体非特异性干扰素样反应和蛋白激酶(PKP)的激活而使其被降解，从而大大减少了其对ｍRNA的抑制作用。 3 RNAi的特点 RNAi被美国科学杂志评为2001年十大科技突破之一，科学家对RNA干扰现象之所以表现出极大关注在于RNA干扰在基因功能和相关方面的研究中具有许多传统方法无法比拟的特点和优势。RNAi有7个重要特征

初中常用动词短语大全

初中常用动词短语大全 1)be back/in/out 回来/在家/外出 2)be at home/work 在家/上班 3)be good at 善于，擅长于 4)be careful of 当心，注意，仔细 5)be covered with 被……复盖 6)be ready for 为……作好准备 7)be surprised (at) 对……感到惊讶 8)be interested in 对……感到有趣 9)be born 出生 10)be on 在进行，在上演，（灯）亮着 11)be able to do sth. 能够做…… 12)be afraid of (to do sth. that…) 害怕……(不敢做……，恐怕……) 13)be angry with sb. 生(某人)的气 14)be pleased (with) 对……感到高兴(满意) 15)be famous for 以……而著名 16)be strict in (with) (对工作、对人)严格要求 17)be from 来自……，什么地方人 18)be hungry/thirsty/tired 饿了/渴了/累了 19)be worried 担忧 20)be (well) worth doing (非常)值得做…… 21)be covered with 被……所覆盖…… 22)be in (great) need of (很)需要 23)be in trouble 处于困境中24)be glad to do sth. 很高兴做…… 25)be late for ……迟到 26)be made of (from) 由……制成 27)be satisfied with 对……感到满意 28)be free 空闲的，有空 29)be (ill) in bed 卧病在床 30)be busy doing (with) 忙于做……(忙于……) 由come、do、get、give、go、have、help、keep、make、looke、put、set、send、take、turn、play等动词构成的词组 31)come back 回来 32)come down 下来 33)come in 进入，进来 34)come on 快，走吧，跟我来 35)come out出来 36)come out of 从……出来 37)come up 上来 38)come from 来自…… 39)do one's lessons/homework 做功课/回家作业40)do more speaking/reading 多做口头练习/朗读 41)do one's best 尽力

常用英语动词短语固定搭配

常用英语动词短语 1. 动词 +about speak/talk about谈论 think about思考 care about 关心 , 对... 有兴趣bring about 引起 ,使发生 set about 着手 , 开始 come about 发生 hear about听说 worry about为...担心 2. 动词 +away throw away扔掉 blow away 吹走 carry away 拿走 , 使入迷clear away 清除掉 , 消散 die away 逐渐消失 pass away 去世 wash away 冲走 take away 拿走 put away 收拾起来 , 存起来give away 背弃 , 泄露 wear away 磨掉 , 消耗 break away 摆脱 send away 让走开 turn away 把 ... 打发走 3. 动词 +back keep back 隐瞒 ,忍住 hold back 控制住 call back 回电话 look back 回顾 give back 归还 take back 拿回 , 收回 4. 动词 +for run for竞选 ask for 要求得到 wait for等候 long for 渴望 care for 关心 , 喜欢 search for 查找 call for要求,需要 change for 用... 换 apply for申请 seek for 寻找完美 .格式 .编辑 stand for 代表 , 表示 hope/wish for希望得到 beg for 乞求 look for 寻找 hunt for寻找 charge for收费,要价 take for误以为...是 come for 来拿 , 来取 5. 动词 +down burn down烧毁 take down记下,记录 cut down 削减 , 砍倒 pass down 传下来 calm down 平静下来 settle down安家 tear down拆毁,拆除 break down 坏了 , 垮了 ,分解turn down调小,拒绝 slow down 慢下来 put down 记下 , 写下 ,镇压bring down 使... 降低 , 使倒下come down 下落 , 传下 6. 动词 +at come at向...袭击 run at 冲向 , 向... 攻击 tear at用力撕 stare at 凝视 glance at 匆匆一瞥 knock at 敲门 , 窗等 smile at 冲某人笑 aim at 向 ... 瞄准 wonder at 惊讶 shout at 冲某人嚷嚷 work at 干... 活动研究 look at 看, 注视 glare at 怒视 laugh at 嘲笑 point at指向 strike at向...打击 shoot at 向 ... 射击 call at 拜访地点 7. 动词 +from differ from与...不同 suffer from受...苦

常用英语动词与介词搭配

常用动词与介词搭配 1．动词＋against brush against 触到，擦及 declare against 表态 fight against 反对，与……做斗争 guard against 提防 hit against 碰撞 inform against /on 告发，检举 insure against 给……保险 lean against 倚，靠，依靠 protect against 抗议 rail against /at 咒骂，严厉责备，抱怨 react against 反对，反其道而行 side against 反对 vote against 投票反对 2．动词＋at aim at 志在，旨在；瞄准，针对 be amazed at 对……大为惊奇 be annoyed at 因……而恼怒 arrive at 到达；得出（结论）；做出（决定） be astonished at 对……感到惊讶 bark at 对……吠 call at 访问（某地）；（车、船等）停靠（某地）direct at 把……对准，针对 drive at意指 exclaim at对……表示惊奇 fire at向……射击 frown at 对……表示不满 be frustrated at 因……而沮丧（或灰心） gaze at 凝视，注视 get at 到达，接近（以取得某物） glance at 瞥见，匆匆地一看 glare at 怒目而视 grab at 抓住，夺得 knock at 敲（门） laugh at 嘲笑，取笑；因……而发笑 look at 看，察看；考虑 peer at 仔细看，费力地看 point at 指向…… run at 冲向，扑向 shoot at 向……射击 shout at 对……叫嚷，对……吼叫 smile at 对……微笑 snap at 猛咬；厉声说话，怒声责骂

Cross-Polarization Interference Cancelation (XPIC)

Cross-Polarization Interference Cancelation(XPIC) Performance in Presence of Non-linear Effects Hugo Proenc?a1,Nuno Borges Carvalho1 1Instituto de Telecomunicac??o es Universidade de Aveiro 3810-193Aveiro,Portugal Tel:+351234377900Fax:+351234377901e-mail:hproenca@ua.pt,nbcarvalho@ua.pt Abstract—Microwave technology,used in main points of mobile backhaul,has now evolved to take advantage of the introduction of Internet Protocol(IP)into the backhaul network to drive higher capacities,increased frequency ef?ciency,increased?exibility,and optimal cost by combining a number of features to enable true gigabit transport speeds.One of those evolutions regards to the frequency reuse schemas like Co-Channel Dual Polarization(CCDP),which uses two parallel com-munication channels over the same link with orthogonal polarizations.Due to the nature of these systems,it is inevitable that cross-polar interference occur(e.g. rainfall,multipath,equipments imperfections...),where Cross-Polarization Interference Cancellation(XPIC) technology is adopt as a countermeasure against that interference.However,this cancelation block,normally located at baseband level,process signals that can be affected by non-linear impairments.This paper shows the performance achieved by two XPIC con?gurations, based on newly introduce XPIC model,in the presence of Saleh model non-linear element,placed at transmit-ter,for a256-quadrature amplitude modulation(QAM) https://www.wendangku.net/doc/933227905.html,DP system,which includes XPIC,is simulated using Simulink tool from Mathworks. Index Terms—CCDP,non-linear effects,Saleh model, Simulink,XPD,XPIC I.SUMMARY The use of CCDP is nowadays common,since it can almost double the link capacity over the phys-ical channel(using orthogonal polarizations).How-ever,cross-polar interference,which can be charac-terized by Cross-Polarization Discrimination(XPD), occurs due to several factors like rainfall,multipath propagation,equipment imperfections,or antennas misalignment.XPIC is considered a key technique for realizing orthogonal polarized wave multiplexing transmission,because it processes and combines the signals from the two receiving paths to recover the original signals.In[1],it is mention that the preferred method to perform cross-polar cancelation is using adaptive channel equalization in combination with an interference canceler.Several realizations using this con?guration can be found in[2]and in[3]and others. In this paper,the XPIC performance under non-linear effects will be presented using simulated re-sults.The simulation are done with a model that Fig.1:Transmitter-Receiver CCDP system simulator(Top Model) has been developed for emulate a transmitter-receiver CCDP system,using Simulink tool from Math-works[4].The XPIC model considered is based on the principle for adaptive interference canceling pre-sented in[5]and the cross-polarization interference channel model used is Rummler’s2-path with cross-polarization interference,which have been used as channel model in[2].The system non-linear elements are characterized by Saleh model,which exhibits non-linear distortions both in amplitude(amplitude-to-amplitude(AM/AM))and phase(amplitude-to-phase (AM/PM))[6]. https://www.wendangku.net/doc/933227905.html,DP SIMULATOR The transmitter-receiver CCDP system simulator general model is presented in?gure1,where4blocks (left to right)can de identi?ed:(1)Transmitter;(2) Channel;(3)Receiver;and(4)bit error rate(BER) measurement.The emulation of the CCDP system is done at the baseband level,i.e.,the signals travels through the channel model as complex numbers and are not modulated using In-Phase and Quadrature (IQ)modulation,and not converted into Intermedi-ate Frequency(IF)or radio frequency(RF),where, simulation of RF stage is also not considered. The Cross-Polarization Interference channel model used is Rummler’s2-path with cross-polarization interference,which have been used as channel model in[7][2][8]. 978-1-4244-7412-7/10/$26.00 ?2010 IEEE

常见动词短语搭配

常见动词短语搭配 1．break短语： break away (from sb./sth.)（脱离，逃脱，甩掉）；break one’s word(食言)； break out(爆发，突然开始，主语多为war，fire，quarrel等，不能用于被动语态)； break down(机器、车辆等坏掉，使分解)；break in(插话，强行进入)； break into(强行闯入，突然开始)；break up(粉碎，关系破裂，垮掉)； break the rules(违反规定，相反含义的有obey the rules)； break the record(打破记录，相当于set up a record，相反含义的有hold a record)； break the silence(打破沉默) 2．bring短语： bring forth（生产）；bring forward（将……提前，提议）； bring down(降低，打落)；bring in(赚得，提出，引进)； bring up(抚养，提出，呕吐)．bring sb. convenience/trouble(给某人带来方便／麻烦) 3．call短语： call at someplace(拜访某地，相当于drop in at someplace)； call on sb.(拜访某人，相当于drop in sb． call for(需要，要求，接)；call on/upon sb. to do sth.（请求某人做某事） 4．get短语： get along／on with(与……和睦相处，进展)； get down to sth,（开始做某事，如：get down to business言归正传）； get in(收割，买进)；get on（进展，获得成功，对付）； get off(下班，出发)；get through(用完，顺利通过，接通电话)； get to(到达，使烦恼)；get up(起床，增强)； get in touch with（与……取得联系）；get rid of(摆脱)； get into trouble(惹麻烦) 5．give短语： give in(投降，让步)；give up(放弃，投降)； give out(散发，耗尽，如：My patience finally gave out:我终于忍无可忍了。)； give off(发出光、热、气味等)；give away(分发，送给) 6．护短语： go out(送出，熄灭)；go with sth.（附属于，同意）； go mad（发疯）；go bad(变坏，变质)； go against(违背)；go on(继续) 7．hold短语： hold back(隐瞒，阻挡，抑制)； hold on(坚持，等着。不要挂掉电话)； hold up（耽搁，支持住）；hold an important position(担任重要职位) 8．keep短语： keep back（保持距离，抑制感情等的流露，隐瞒）；keep off(回避某话题，使……不接近)； keep away from(远离)；keep up with sth.（熟悉，继续支付） keep up with sb.（与某人保持联系）；keep on(继续)； keep a record（保持记录）；keep one's promise（遵守诺言）； keep an eye on(照看，留神，留意)

初中常用动词短语全集

初中常用动词短语全集集团企业公司编码：（LL3698-KKI1269-TM2483-LUI12689-ITT289-

look短语 look for寻找；look after照顾；look over查看；look forward to渴望，向往，to为介词，后接名词、代词、动名词作宾语；look at看着；look up抬头看，在…查找；look up to尊敬；look down upon瞧不起；look like看起来像；look as if/though看起来好像；look through透过……看 ,翻阅，浏览；look into调查；look out当心；look out of往…外看look about [around]环顾四周look back 回顾，回想look on旁观, 看作，当作(与a s连用) put短语 put off推迟，put on穿上；上演；put away把…暂时收起来，储存……备用；put up举起，建造，张贴；put out扑灭；put down写下；放下；put aside把…搁在一边；put back放回put…into把…放入 put one’s heart into全神贯注 turn短语 turn down把音量开小一点;拒绝；turn up把音量开大一点;出现； turn over翻开;翻转；turn to朝向;变成;求助于；turn…into…把…变成…；turn into变成；turn out结果证明是；turn away把脸转过去turn to sb转向某人 turn out结果是turn on 打开(电灯等) turn off 关(电灯等) turn against背叛turn back折回，往回走 turn around旋转，转过身来call短语 call at拜访，后接地点；call on拜访，后接被拜访的对象；号召；call back回电话；call in 叫来；call up打电话，使回忆起；call for叫某人同往某处，要求；call off取消 be短语 be friendly/kind to对…友好；be fed up with对…厌烦；be different from与…不同；be afraid of害怕；be popular with受…欢迎；be fond of喜欢，爱好；be interested in对…感兴趣；be surprised at 对…惊讶；be satisfied/content/pleased with对…满意；be proud of对…感到自豪；be strict with对某人严格；be strict in 对某事严格；be good to对…有好处；be good at擅长于…；be good with…善于应付……的；对……有办法； be sure of/about对…有把握；be divided into被分成；be made up of由…构成；be angry with对某人生气；be busy with忙于；be full of/filled with装满了；be late for…迟到；be covered with覆盖