MMSE adaptive receiver vs. rake receiver performance evaluation for UWB signals over multipath fading channel

Transcription

1 Internatonal Journal o Wreless Communatons, Networkng and Moble Computng 2015; 1(02): Publshed onlne ( MMSE adaptve reever vs. rake reever perormane evaluaton or UWB sgnals over multpath adng hannel Nadr Mohamed Abd Elazz 1, Abdelrasoul J. Alzubad 2, Mustaa A. Hassan 1 1 Al Nlan Unversty, College o Postgraduate Studes Dept. o Eletrons & Communaton Engneerng, Sudan 2 Sudan Unversty o sene and Tehnology, Engneerng College, Dept. o Eletrons, Sudan Keywords Ultra-Wdeband (UWB), Multple-Aess-Intererene (MAI), Bt-Error-Rate (BER), Sgnal-to-Intererene-Nose Rato (SINR), Mnmum-Mean-Square-Error (MMSE) Reeved: January 09, 2015 Revsed: January 17, 2015 Aepted: January 18, 2015 Emal address alpronnty@gmal.om (N. M. A. Elazz), Rasoul46@lve.om (A. J. Alzubad) Ctaton Nadr Mohamed Abd Elazz, Abdelrasoul J. Alzubad, Mustaa A. Hassan. MMSE Adaptve Reever vs. Rake Reever Perormane Evaluaton or UWB Sgnals over Multpath Fadng Channel. Internatonal Journal o Wreless Communatons, Networkng and Moble Computng. Vol. x, No. x, 2014, pp. x-x. Abstrat Ths paper presents a perormane omparson between Mnmum-Mean-Square-Error (MMSE) adaptve reever as a reepton algorthm utlzng a new spe template Ultra-wdeband (UWB) pulse shape, and the perormane o onventonal Ultra-Wdeband (UWB) Rake reever wth derent number o Rake ngers. MMSE adaptve algorthm s more eent and powerul beause o ts ablty and eatures o adaptaton to the substantal hanges n the UWB multpath wreless ommunaton hannel model proposed by the IEEE a workng group based on moded (S-V) hannel model; employng two ommonly used transmsson and multple aess shemes n UWB ommunatons whh are Dret-Sequene (DS-UWB) and Tme-Hoppng (TH-UWB). Moreover, the perormane omparson between the two reepton shemes presented n ths paper s assumed to be perormed n the presene o both; narrowband ntererene omng rom other networks (e.g. IEEE a WLAN), and also the presene o Multple-Aess-Intererene (MAI) omng rom other UWB users n the proxmty o the desred UWB user. 1. Introduton The eld o UWB has drawn a lot o attenton and study eort n the last ew years as t seems to be a better anddate ompared to most o the exstng wreless rado tehnologes supportng short-range hgh-speed (hgh data rates) ommunaton networks. A substantal hange ourred n February 2002; when the Federal Communaton Commttee (FCC) has ssued rulng report states that UWB sgnals wth ts assoated very wde bandwdth (7.5 GHz), and extremely low power-spetral-densty (PSD) up to dbm ould be used or ommeral data ommunaton applatons suh as wreless Personal Area Networks (WPANs), the FCC regulaton report denes the UWB sgnal as a sgnal that has a 10dB bandwdth spetrum greater than at least 500 MHz, or a sgnal that has a ratonal bandwdth ( ) greater than or equal to 0.20 [1], the ratonal bandwdth s F BW dened by the ollowng equaton; whereas represents the entral requeny, and C H L orrespond to the hgh and low requenes dentyng the 10dB bandwdth respetvely [1].

2 2 Nadr Mohamed Abd Elazz et al.: MMSE Adaptve Reever vs. Rake Reever Perormane Evaluaton or UWB Sgnals over Multpath Fadng Channel H L H L F BW (1) C Furthermore, UWB beame an emergng soluton or the IEEE a (TG3a) standard; whh s to provde a low omplexty, low ost, low power onsumpton and hgh data rates among WPANs deves. UWB systems are onsdered more preerable due to the smple desgn o the transever struture resultng rom the at that; UWB sgnals are arrer less (transmtted wthout any arrer snusodal wave); the eature that elmnates the need or modulator, demodulator, and osllators rutres n the transever struture. UWB ommunatons utlzes extremely narrow pulses to onvey the arrer less UWB sgnals over the nherted wde spetrum bandwdth [1] [2]. However, the system model s ntrodued n seton II whh haraterzes the UWB pulse shapes used n the paper and the proposed UWB multpath hannel models. Whle the transmsson and multple aess shemes are presented n seton III. Seton IV demonstrates n detals the blok dagrams and theory o operaton o the derent reepton shemes and reever strutures. The smulaton and perormane omparson results are llustrated usng MATLAB R2013b and Smulnk lbrares n seton V. Fnally, seton VI onludes the nshng results o the perormane evaluaton or the derent reever strutures dsussed n the paper. 2. System Model 2.1. UWB Pulse Shape H L doman GHz or ts ablty to onvey normaton wth very hgh data rates nherted rom the ultra-wde bandwdth (7.5 GHz). UWB utlzes extremely narrow pulses (sub-nanoseond) to spread ts sgnal s power over the wde bandwdth, takng to onsderaton that these extremely narrow pulses must ulll the FCC power spetral densty (PSD) requrements presented n the rulng report as UWB systems ndoor spetral Mask lmts shown n Fg. 1. The narrow UWB pulses are emtted rom the transmtter n a unque rhythm alled Pulse Repetton Rate assoated to eah transmtter and t must be known at the reever to be able to detet the data and normaton sgnal beng transmtted. One undamental hallenge s to maxmze the radated UWB pulse energy; yet to assure that the pulse s PSD omples wth the FCC spetral mask lmts. Moreover, sne the extremely narrow pulses are relatvely easy to generate wth analog omponents; the Gaussan monoyle pulse and ts dervatves are ommonly used as bas UWB pulse shapes beause ther PSD omply wth the FCC mask power lmts as demonstrated n Fg. 2 [3] [4]. Hene, the pulse shapes used n the smulaton n the paper are the dervatves o the Gaussan monoyle pulse whh an be expressed n the ollowng equaton: y d ( t) dt n n t A exp( ) Gn.. (2) Where; A s the normalzed Pulse ampltude, and s a tme-salng ator and ts relaton to the pulse wdth T s that TP 7 whh ontans about 99.98% o the total pulse energy. 2 P Fg. 2. PSDs o hgher order dervatves o UWB Gaussan pulses Fg. 1. UWB ndoor Radated power mask regulated by FCC Sne FCC ssued a rulng report n February 2002 authorzng that UWB tehnology s onsdered an nterestng anddate or ndoor wreless ommunatons n the spetrum It an be seen rom Fg. (2) that; PSD o the rst dervatve o the Gaussan monoyle pulse does not totally t wthn the FCC spetral mask. Thereore, another pulse shapes ounded rom dervatves o the Gaussan Pulse beause the hgher-order dervatves nreases the number o zero

3 Internatonal Journal o Wreless Communatons, Networkng and Moble Computng 2014; x(x): xx-xx 3 rossngs whh orrespond to hgher arrer requeny snusod modulated by an equvalent Gaussan envelope. Thus, the Gaussan Doublet whh s the 2 nd dervatve o the Gaussan Pulse expressed n (3) s the most ommonly used UWB pulse shape n the lterature [4]. However, ths paper studes and analyzes the perormane o the 6 th dervatve o the Gaussan Pulse represented n (4) sne t satses more the power lmts o the FCC report and ts muh better nto the mask lmts as shown n Fg. (2). t 2 t 2 y G 2 ( t) 1 4 ( ) exp 2 ( ).. (3) t 2 2 t t 6 t 2 y G 6 ( t) 112 ( ) 16 ( ) ( ) exp 2 ( ). (4) UWB Multpath Channel Model The moded Saleh-Valenzuela (S-V) model s used n the paper sne t was adopted as a reerene UWB hannel model by the IEEE a workng group. The modelng proess s based on an ndoor propagaton envronment pratal measurement, and the man dstnt eatures o the UWB propagaton hannel are; the extremely rh multpath omponents prole and the non-raylegh adng ampltude haratersts. In UWB propagaton there are muh more multpath omponents than any other wreless propagaton hannels. As a result o the wde bandwdth o UWB pulses waveorms; the derent objets exst n the ndoor envronment wll gve a rse to muh several multpath omponents all o whh would be a part o one luster. Thus, the multpath omponents arrve at the reever end n the orm o lusters, and wthn eah luster there wll be multple subsequent arrvals alled rays. Thereore, Tme-O-Arrval (TOA) statsts the IEEE a standard model used (S-V) approah whh modeled multpath omponents n lusters and rays. Sne UWB pulses are extremely narrow; only ew multpath omponents overlap wthn eah resolvable delay bn. Consequently; the entral lmt theorem s not applable and the ampltude adng statsts are not suently represented by Raylegh dstrbuton. The IEEE a standard adopted the moded (S-V) model beause ts ampltude adng statsts are Log-normally dstrbuted [4]. The mpulse response o the moded (S-V) model s represented n equaton (5) [2] [4]: h ( t) Where; L C 1K LC 1 l0 k0.(5) k, l ( t Tl k, l ) k.l represents the multpath gan oeents, represents the delays o the l th luster, T l k,l represents the delays o the k th multpath omponent ray wthn the l th luster arrval tme ( T ). Shadowng eet o the total l multpath energy s log-normal dstrbuted and s represented by the term, and reers to the th realzaton. A alulaton o the delay haratersts o the moded (S-V) model mpulse response presented n (5) smulated usng MATLAB and the smulaton results are shown n Fg. 3. as an be seen n the gure; or any longer delay n tme-doman the ampltudes o UWB sgnal s pulses are more dereasng and redued; whh s expressed as Fadng due to the multpath delay spread o the derent rays wthn eah o the derent lusters. Fg. 3. Impulse Response and Delay Prole o Moded Saleh-Valenzuela Model The IEEE a standard multpath hannel proposal has dened our derent models or derent senaros based on pratal measurements ound n the ndoor envronment whh are haraterzed as: CM1: Lne-O-Sght (LOS) model or dstane 0 4 m between T and R. CM2: Non-LOS (NLOS) model or dstane 0 4 m between T and R. CM3: NLOS model or dstane 4 10 m between T and R. CM4: NLOS or 4 10 m between T and R, wth extreme (dense) multpath hannel ondton Transmsson and Multple Aess As mentoned n the prevous seton the UWB pulses must be transmtted as a tran o pulses n a rhythm or a regular tme alled pulse repetton rate to arry the normaton sgnal or short range (ndoor envronment). However, ths regular pulse repetton rate wll ause relatvely large requeny PSD peaks o ampltude n the orrespondng spetrum at a ertan requenes represent the nverse o the pulse repetton rate as

4 4 Nadr Mohamed Abd Elazz et al.: MMSE Adaptve Reever vs. Rake Reever Perormane Evaluaton or UWB Sgnals over Multpath Fadng Channel presented n Fg. 4.a and 4.b respetvely whh ontradts and breahes the FCC power mask regulatons. However, one approah to avod the regular perod transmsson o UWB pulses s to dther the transmtted UWB pulse tran by addng a small random oset to eah pulse, ether delayng the pulse or transmttng slghtly beore ts regular tme. The resultant spetrum rom suh a random oset s shown n Fg. 5; whh presents an observable reduton n the PSD ampltude peaks ompared to Fg. 4.b. Fg. 5. Spetrum o the dthered UWB pulse tran s ( k ) tr N 1 C ( k ) ( k ) ( t) P b w ( t jt nt ). (6) k j n0 j n tr Fg. 4. (a) UWB pulse tran. (b) Frequeny spetrum o UWB pulse tran. Furthermore, the same approah besdes dtherng the UWB sgnal perod pulse tran and redung the PSD ampltude peaks, t also an be used as a multple aess sheme or dstngushng eah derent UWB User by ts own random oset. There are two randomzng tehnques multple aess shemes an be employed to aheve the requred goals whh are; Dret-Sequene UWB (DS-UWB), and Tme-Hoppng UWB (TH-UWB). In DS-UWB the Bandwdth spreadng eet s aheved by the UWB pulse shapng. The bas ormat o the DS-UWB or the kth mpulse rado ( ) transmtter (user) output sgnal S k tr ( t) s gven by equaton (6) [4]: Where; wtr () t represents the transmtted UWB pulse ( k ) monoyle, denotes the PN sequene assoated to the kth user, n T s the symbol (rame) perod, T s the hp perod suh that T N T b represents the normaton bt ( k) j stream o the kth user, P k s the transmtted power orrespondng to the kth user. n s an nteger= 0,1,2,.., ( k ) n represents the PN sequene assoated to the kth user, (k ) b j 1 s the BPSK data (bt) stream o the k th user, T s the pulse repetton perod (rame tme), T s the hp perod. Whle Tme-Hoppng UWB usually utlzes Pulse-Poston-Modulaton (PPM) as a modulaton sheme. In UWB systems the pulses are assumed to be one o desred UWB pulse shapes mentoned n the prevous sub-seton. The bas ormat o the TH usng PPM or the kth user transmtted sgnal s gven by [4]: j ( k ) ( k ) ( k ) s ( t) w ( t jt T b T ) tr Where; tr j j PPM. (7) (k ) j represents the PN Tme-Hoppng sequene assoated to the kth user, T PPM represents the pulse tme-sht or the Pulse-Poston-Modulaton (PPM). The tme-sht element o the TH ode word assgned to the kth user s hosen rom the set: j = 0, 1, 2 N 1; Where N s the number o tme-delay bns (hps) n a rame tmet.

5 Internatonal Journal o Wreless Communatons, Networkng and Moble Computng 2014; x(x): xx-xx Reepton Shemes and Strutures The extremely narrow pulses used n UWB systems gve a rse to the phenomena o Multpath haraterzed by the UWB wreless hannel dsussed prevously n seton II due to the mehansms o releton, draton, and satterng whh ause the transmtted UWB sgnal to be; dverted nto many paths, and ts energy to be dspersed, and also to arrve at the reever end ater some delays aordng to eah path length and losses. UWB systems utlze spread spetrum tehnques as (DS) and (TH) mentoned n seton III; the thng that requre great auray n sgnal aquston, synhronzaton, and trakng at the reever end UWB Rake Reever The prevously mentoned UWB multpath hannel ondtons ause sgnant sgnal degradatons, and onsequently make t essental to solve the dspersed sgnal energy problem and apture as muh energy as possble to reonstrut the heavly degraded UWB sgnal. Rake reever s a sngle-user detetor desgned to ollet as muh energy as possble rom the sgnal s multpath omponents and then ombne ther ontrbutons together to estmate the transmtted symbol [3]. The UWB Rake reever extrats normaton modulated on the UWB Gaussan pulse rom the degraded and dstorted reeved waveorms wth hgh auray utlzng orrelators as seen n Fg. 6. Moreover, Rake reever attempts to ollet the tme-shted versons o the orgnal UWB sgnal by provdng a separate orrelaton reever or eah o the multpath omponents; eah o the orrelator reevers s adjusted n tme delay so that t an searh n derent tme wndows alled searh wndow or sgnant multpath omponents. Rake reever utlzes multple orrelators to separately detet the strongest multpath omponents; and then the outputs o the orrelators are weghted to provde a better estmate o the transmtted UWB sgnal than s provded by a sngle omponent. Fg. 6. UWB Rake reever Blok dagram The term All Rake (A-Rake) s used n the lterature to ndate the Rake reever wth unlmted resoures that utlzes all the multpath omponents or orrelator taps as shown n Fg. 7. Thereore, ths type o Rake reever s onsdered eent rom the energy apture perspetve; yet, t s onsdered neent rom the rut mplementaton and omplexty pont o vew. Another struture o UWB Rake reever s the Seletve Rake (S-Rake) whh selets and ombnes the M best multpath omponents or taps out o the total L multpath omponents that s determned by the Rake nger seleton algorthm as presented n Fg. 8 [4] [5]. Furthermore, the Partal ombnng Rake reever struture (P-Rake) uses N multpath omponents out o the total L avalable dversty multpath; but t ombnes the rst N arrvng omponents whh are not neessarly the strongest nor the best. The P-Rake struture has drastally redued the omplexty ompared to the S-Rake struture due to the absene o the seleton mehansm. Thus, the P-Rake mtgates the need to sort the multpath omponents by ther nstantaneous path gan magntudes whh would requre a hghly aurate hannel estmaton proess. Fg. 7. All Rake reever Blok dagram

6 6 Nadr Mohamed Abd Elazz et al.: MMSE Adaptve Reever vs. Rake Reever Perormane Evaluaton or UWB Sgnals over Multpath Fadng Channel Fg. 8. Seletve Rake reever Blok dagram Instead, the P-Rake struture only needs to nd the poston o the rst arrvng multpath omponent, whh leads to a substantal rut omplexty reduton Mnmum Mean Square Error (MMSE) Algorthm Sgnant studes have been made on an adaptve orrelator reever by Pateros and Saulner n the eld o Dret-Sequene Spread Spetrum (DS-SS) systems employng BPSK sgnalng n a sngle user, tme-nvarant multpath envronment; these studes have proven that MMSE algorthm reever detets the transmtted data, removes the ntererene, and oherently ombnes the multpath omponents o the sgnal n the presene o Narrowband Intererene (NBI). However, ths paper demonstrates the perormane o the MMSE orrelator reever wth ts adaptve algorthm and apabltes or both DS-UWB and TH-UWB transmsson shemes dsussed prevously n seton III. A major advantage o the MMSE sheme relatve to other ntererene suppresson reepton shemes s that; explt knowledge o the ntererene parameters s not requred. Instead, the UWB reeved sgnal (template 6 th dervatve Gaussan pulses) rom the multpath omponents an be sampled at a rate equal to the Pulse-Repetton-Frequeny ater passng through the orrelator reevers wth ther path seleton mehansm, and then the samples are lnearly ombned usng the MMSE algorthm rtera to suppress the NBI and onsequently maxmze the SINR as shown n Fg. 9. Fg. 9. UWB MMSE reever Sheme Moreover, the MMSE adaptve algorthm reever onssts o two parts; Frst, orrelator reevers whh ombnes the ontrbuton o the strongest best multpath omponents and mtgates the eet o nose to maxmze the SNR. Seond, the adaptve lter whh s manly a Fnte-Impulse-Response (FIR) dgtal lter that essentally ats as a mathed lter to orrelate the reeved UWB pulse waveorm wth the well-known template waveorm and then re-adjusts the orrelator reever s taps weghts to mnmze the Mean Square Error usng an adaptve algorthm despte the type o nose and ntererene may be present n order to maxmze the SINR as demonstrated presely n Fg. 10 [6].

7 Internatonal Journal o Wreless Communatons, Networkng and Moble Computng 2014; x(x): xx-xx 7 Fg. 10. MMSE Adaptve Algorthm reever Blok dagram Adaptve algorthms suh as Reursve Least Squares (RLS) adaptve lter s an algorthm whh reursvely nds the lter oeents that mnmze a weghted lnear least squares ost unton relatng to the nput sgnals. Ths s n ontrast to other adaptve algorthms suh as Least Mean Squares (LMS) that am to redue the mean square error. In the dervaton o the RLS n [5], the nput sgnals are onsdered determnst, whle or the LMS and smlar algorthm they are onsdered stohast. Compared to most o ts ompettors, the RLS exhbts extremely ast onvergene. However, ths benet omes at the ost o hgh omputatonal omplexty [5]. 3. Smulaton and Results The paper presents perormane evaluaton o two derent transmssons multple aess tehnques over UWB multpath NLOS hannel employng two derent reever strutures and shemes on BER vs. SNR bass, assumng the utlzed UWB template pulse shape to be the 6 th dervatve Gaussan pulse demonstrated n equaton (4). The smulaton results are obtaned by MATLAB odes and SIMULINK lbrary bloks and ommunaton tools or; the perormane omparson between DS-UWB and TH-UWB usng BPM and PPM modulaton tehnques respetvely, n the presene o AWGN along wth NBI presumed to be omng rom IEEE a WLAN soure over UWB multpath NLOS hannel based on the moded (S-V) hannel model CM3. Moreover, the smulatons present another mportant perormane omparson between two sgnant reever strutures shemes; Frst, Rake reever wth nger seleton mehansm and derent number o ngers (4 ngers, 8 ngers, and 128 or an nnte number o ngers). Seond, Mnmum Mean Square Error (MMSE) orrelator reever wth LMS, RLS adaptve algorthms to re-adjust the tap weghts or nose and ntererene suppresson to maxmze the SINR. The rest o the key smulaton parameters are lsted n Table. 1. Table. 1. Smulaton Key Parameters Pulse Shape 6 th dervatve Gaussan pulse Pulse Wdth ns Pulse Ampltude 3 volts Channel Model S-V hannel model (CM 3) Transmsson Multple Aess Tehnques Dret Sequene Tme Hoppng Modulaton Tehnques B-phase Modulaton (BPM) or DS Pulse-Poston-Modulaton (PPM) or TH PN Code Length N 16 Intererenes Reever Shemes Chp Rate NBI rom IEEE a WLAN MUI rom 15 UWB users Rake Reever MMSE Correlator wth LMS, RLS adaptve algorthms 1.6 GHz

8 8 Nadr Mohamed Abd Elazz et al.: MMSE Adaptve Reever vs. Rake Reever Perormane Evaluaton or UWB Sgnals over Multpath Fadng Channel Fg. 11. Perormane o DS-UWB over Multpath NLOS Channel wth AWGN but no Intererene Fg. 12. Perormane o TH-UWB over Multpath NLOS Channel wth AWGN but no Intererene Fg. 13. Perormane o DS-UWB over Multpath NLOS Channel wth One NBI (SIR= -30 db)

9 Internatonal Journal o Wreless Communatons, Networkng and Moble Computng 2014; x(x): xx-xx 9 Fg. 14. Perormane o TH-UWB over Multpath NLOS Channel wth One NBI (SIR= -30 db) Fg. 15. Perormane o DS-UWB over Multpath NLOS Channel wth One Stronger NBI (SIR= 0 db) Fg. 16. Perormane o TH-UWB over Multpath NLOS Channel wth One Stronger NBI (SIR= 0 db)

10 10 Nadr Mohamed Abd Elazz et al.: MMSE Adaptve Reever vs. Rake Reever Perormane Evaluaton or UWB Sgnals over Multpath Fadng Channel Fg. 17. Perormane o DS-UWB over Multpath NLOS Channel wth Multple UWB Intererers (MUI o 15 UWB users) Fg. 18. Perormane o TH-UWB over Multpath NLOS Channel wth Multple UWB Intererers (MUI o 15 UWB users) Fg. 19. Perormane o DS-UWB over Multpath NLOS Channel wth ombned NBI (SIR = -30 db) and Multple UWB Intererers (MUI)

11 Internatonal Journal o Wreless Communatons, Networkng and Moble Computng 2014; x(x): xx-xx 11 Fg. 20. Perormane o TH-UWB over Multpath NLOS Channel wth ombned NBI (SIR = -30 db) and Multple UWB Intererers (MUI) Fg. 21. Perormane o DS-UWB over Multpath NLOS Channel wth ombned Stronger NBI (SIR = 0 db) and Multple UWB Intererers (MUI) Fg. 22. Perormane o TH-UWB over Multpath NLOS Channel wth ombned Stronger NBI (SIR = 0 db) and Multple UWB Intererers (MUI)

12 12 Nadr Mohamed Abd Elazz et al.: MMSE Adaptve Reever vs. Rake Reever Perormane Evaluaton or UWB Sgnals over Multpath Fadng Channel Furthermore, as demonstrated n the prevous MATLAB smulaton Fgures (11, 12, 13 22); the paper has examned the perormane o both; Rake reever struture wth derent number o Rake ngers, and MMSE orrelator reever struture analytally and wth derent adaptve algorthms RLS and LMS usng the smulaton key parameters n Table. 1 or the ollowng ve senaros: Multpath NLOS Channel wth only AWGN but no Intererene (nether NBI nor MUI). Multpath NLOS Channel wth the eet o a sngle NBI Soure wth SIR= -30 db Multpath NLOS Channel wth the eet o a stronger sngle NBI Soure wth SIR= 0 db Multpath NLOS Channel wth the eet o Multple UWB Intererene soures (15 MUI soures). Multpath NLOS Channel wth the ombned eet o both sngle NBI soure and Multple UWB Intererene soures (15 MUI soures). 4. Conluson Ths paper presents a detaled perormane evaluaton o two sgnant UWB reepton strutures and shemes; UWB Rake reever wth derent number o Rake ngers (4, 8, and 128 nnte ), and MMSE orrelator reever wth derent adaptve algorthms (RLS, and LMS), usng the 6 th dervatve Gaussan pulse a new template UWB pulse over multpath NLOS hannel based on the moded (S-V) hannel model CM3 utlzng DS and TH as transmsson and multple aess tehnques. Based on the smulaton key parameters n Table (1) examned or the ve study ase senaros stated n the prevous seton, the smulaton results show that; perormane o DS-UWB as a transmsson and multple aess tehnque s slghtly better than TH-UWB tehnque speally n the presene o ether Narrowband Intererene (NBI) or Multple User Intererene (MUI) n addton to the AWGN. Furthermore, as the Narrowband Intererene grow stronger (poorer SIR); the perormane o Rake reever wth more Rake ngers s proven to be more eent than the one wth less Rake ngers. However, the reepton perormane has obvously mproved and extensvely developed when employng the Mnmum Mean Square Error (MMSE) orrelator reever whether analytally or utlzng adaptve lter algorthms suh as RLS and LMS speally n ase o MUI aused by other UWB users n the proxmty o the man desred UWB soure. 5. Future Sope The paper presented a detaled perormane evaluaton omparson between UWB Rake reevers wth derent number o Rake ngers and MMSE orrelator reever wth derent adaptve tehnques utlzng the 6 th dervatve Gaussan pulse as a new UWB template pulse shape over Multpath adng hannel based on the moded (S-V) hannel model (CM3). Thus, or more eetve presentatons o derent pratal senaros; more UWB template pulse shapes should be utlzed to experene ther perormane over the multpath adng hannel model employng the reepton tehnques and shemes n the paper. Furthermore, the researh suggests adoptng the UWB multpath hannel based on the moded (S-V) model (CM4) whh represents the NLOS hannel wth dense and extreme multpath ondtons or more realst and eent ndoor envronment perormane evaluaton. Reerenes [1] Ian Oppermann, Matt Hamalanen UWB Theory and Applatons, Book, pp [2] M.Ghavam, L.B.Mhael Ultra-Wdeband Sgnals and Systems n Communaton Engneerng, Book, pp [3] B. M.Mezzour, Dret Sequene UWB perormane over STDL paper Journal, vol.3. [4] Nadr. Abd Elazz, Abdelrasoul. Alzubad, Perormane o the 6 th dervatve Gaussan Pulse Shape n IEEE a Multpath Fadng Channel IOSR journal o Engneerng, Vol3, Issue Deember [5] Rashd A. Fayyadh, F. Malk Adaptve Rake reever usng Mathed Flter wth Three Combnng Tehnques Australan Journal o Bas and Appled Senes, 7(5): 26-33, 2013 ISSN [6] Rashd A. Fayyadh, Improved Rake Reever Based On the Sgnal Sgn Separaton n Maxmal Rato Combnng Tehnque or Ultra-Wdeband Wreless Communaton World Aademy o Sene, Engneerng and Tehnology, Internatonal Journal o Eletral, Robots, Eletrons and Communatons Engneerng Vol:7 No:12, 2013.