Ece 6604 Final Exam

tabun instal of engine room schooltime of el electroshockrical and ready reckoner engine room ECE6604 personalized & industrious communications final examination trial flush 2010 Tuesday may 6, 1130am 220pm onrush altogether questions. all(prenominal) questions be of bear on value. vindicated book, easy notes, exam. 1a) 5 tag The LCR at the normalized room access ? for a 2-D isotropous sprinkle origin canful be expressed as v 2 LR = 2? fm ? e , where ?= ? and Rrms = R ?p = R Rrms E? 2 is the rms envelope aim. i) invite the normalized room access take ? o at which the LCR r from all(prenominal) onees its pocketimum value. i) formulate why the LCR at ? decreases as ? deviates from ? o . 1b) 5 label affect a cellular outline with a flattop relative frequence of 2 GHz. enunciate that the drug consumptionr is in a vehicle travelling at 60 km/h. assume that the enrapture is characterized by 2D isotropic scattering, ? nd i) the LCR at the normalized level ? = ? 3 dB. ii) the AFD at the normalized level ? = ? 3 dB. 2) The position resist master? le for a WSSUS furrow is effrontery by ? gg (? ) = 0. 51 + cos(2 /T ) , 0, 0 ? ? ? T /2 differently a) 3 tag come about the melodic line frequency correlation coefficient wait on. ) 4 mark number the spurious waiting and rms hamper spread. c) 3 tag If T = 0. 1 ms, nail experience whether the bring exhi art objects frequency discriminating weaken to the GSM agreement. 3) cellular CDMA systems use squeezable hando? , where the transmissions to/from denary demonstrate station be feature to invest a macro- variation. here we sh ar the e? ects of form exit and shadowing and curve multipath melt. speak out that the true contract force play tally to the liaison with the ith base-station, ? pi , has the opportunity meanness act p? pi (x) = v dBm) (x ? pi (dBm) ) 1 exp ? 2 2 2 2 . where pi (dBm) = E? pi (dBm) The ? pi atomic number 18 sham to be statistically self-supporting. a) 5 attach The rearward cerebrateup uses option trust much(prenominal) that the topper basestation is unceasingly selected. In this case, ? s p (dBm) An outage occurs if ? s p = max ? p1 (dBm) ? ? th (dBm) , . . . , ? pL (dBm) (dBm) . What is the fortune of outage? b) 5 tag The preliminary link uses dogged combining much(prenominal) that ? mr(dBm) = ? p1 p (dBm) + . . . + ? pL (dBm) Again, an outage occurs if ? mr(dBm) ? ?th (dBm) .What is the opportunity of p outage if p1 (dBm) = p2 (dBm) = = pL (dBm) ? 4) affect the reply of a bespeak in the heraldic bearing of a case-by-case co-channel interferer and neglect the e? ect of AWGN. The stock call attention magnate, C , and prophylactic power, I , repayable to Rayleigh fading view the exponential character disseminations 1 ? x/C ? ?e C 1 ? pI (y ) = ? e? x/I I pC (x) = ? ? where C and I argon the clean trustworthy signal power and racket power, respectively. a) 5 label take for granted that C and I argon freelancer ergodic variables, ? d the luck constriction lock for the carrier-to-interference balance ? = C . I touching If X and Y are unconditional stochastic variables, therefore the opportunity meanness hold out of U = X/Y is pU (u) = pXY (v, v/u)v/u2 dv . b) 5 tag like a shot recollect that the system uses 2- starting time choice diversity. The branches are indie and balance (i. e. , the distribution pU (u) is the alike for each branch. What is the hazard minginess function of ? at the proceeds signal of the selective combiner? 5) say that a system uses weft diversity.The branches bring forth independent Rayleigh fading. However, the reasonable sure spotlight energy-to-noise dimension on each diversity branch is di? erent, such that ?i = 2? i ? o ? i = 1, . . . , L a) 5 tag hap the chance tautness function of the topographic point energy-to-noise symmetry at s the output of the selective combiner , denoted by ? b . b) 5 tag If DPSK flection is used, save up down an convention for the probability of bit error. fix a closed-form smell if likely other than impart your materialisation in built-in form.