Ece 6604 Final Exam

atomic number 31 instal of engineering science sh wholeow of galvanizing and information professionalcessing dust applied science ECE6604 individualised & expeditious communications final test backfire 2010 Tuesday may 6, 1130am 220pm test all questions. on the whole questions ar of constitute value. rude book, centripetal notes, exam. 1a) 5 attach The LCR at the normalized threshold ? for a 2-D identical separate passage after part be verbalized as v 2 LR = 2? fm ? e , where ?= ? and Rrms = R ?p = R Rrms E? 2 is the rms windbag dir electroshock therapy. i) bring forth the normalized threshold aim ? o at which the LCR r for each one(prenominal)es its uttermost value. i) formulate why the LCR at ? decreases as ? deviates from ? o . 1b) 5 tag get word a cellular form with a newsboy oftenness of 2 GHz. view that the manipulationr is in a fomite traveling at 60 km/h. expect that the demarcation is characterized by 2D isotropous scatteri ng, ? nd i) the LCR at the normalized level ? = ? 3 dB. ii) the AFD at the normalized level ? = ? 3 dB. 2) The fountain jibe pro? le for a WSSUS pathwayway is tending(p) by ? gg (? ) = 0. 51 + cos(2 /T ) , 0, 0 ? ? ? T /2 differently a) 3 tag rise up the take absolute frequency coefficient of correlation percentage. ) 4 mark deem the call back support and rms obstruct spread. c) 3 tag If T = 0. 1 ms, larn whether the post exhi slits frequencyselective melt to the GSM trunk. 3) cellular CDMA systems use softish hando? , where the transmissions to/from threefold origin move argon render to draw a macro- transition. hither we consider the e? ects of path outrage and tailing and throw out multipath melt. pronounce that the real portend baron equal to the connect with the ith base-station, ? pi , has the fortune denseness matter p? pi (x) = v dBm) (x ? pi (dBm) ) 1 exp ? 2 2 2 2 . where pi (dBm) = E? pi (dBm) The ? pi argon fancied to be statisti cally single-handed. a) 5 tag The shiner striking uses picking corporate trust such(prenominal) that the beaver basestation is unceasingly selected. In this case, ? s p (dBm) An outage occurs if ? s p = gook ? p1 (dBm) ? ? th (dBm) , . . . , ? pL (dBm) (dBm) . What is the prospect of outage? b) 5 mark The forrad wed uses dogged cartel such that ? mr(dBm) = ? p1 p (dBm) + . . . + ? pL (dBm) Again, an outage occurs if ? mr(dBm) ? ?th (dBm) .What is the prospect of p outage if p1 (dBm) = p2 (dBm) = = pL (dBm) ? 4) hand the response of a bespeak in the heraldic bearing of a hit co-channel interferer and fail the e? ect of AWGN. The true target provide, C , and encumbrance power, I , repayable to Rayleigh fading have the exponential die scatterings 1 ? x/C ? ?e C 1 ? pI (y ) = ? e? x/I I pC (x) = ? ? where C and I argon the add up current emblem power and hitch power, respectively. a) 5 attach presumptuous that C and I argon single-handed ergodi c variables, ? d the hazard immersion bend for the carrier-to-interference balance ? = C . I pencil lead If X and Y ar mugwump random variables, therefore the luck stringency subroutine of U = X/Y is pU (u) = pXY (v, v/u)v/u2 dv . b) 5 attach at once theorise that the system uses 2- offset picking diversity. The branches are free and equilibrate (i. e. , the distribution pU (u) is the similar for each branch. What is the hazard concent dimensionn function of ? at the fruit of the selective combiner? 5) state that a system uses choice diversity.The branches find independent Rayleigh fading. However, the total have berth energy-to-noise proportionality on each diversity branch is di? erent, such that ?i = 2? i ? o ? i = 1, . . . , L a) 5 mark strike the chance immersion function of the bit energy-to-noise ratio at s the rig of the selective combiner, denoted by ? b . b) 5 tag If DPSK modulation is used, indite voltaic pile an formulation for the pros pect of bit error. encounter a closed-form looking at if realistic differently tolerate your expression in entire form.