ta lN o 3 dB C hanne l CM 3 16 32 48 64 80 96 112 128 400 300 200 100 100 200

Ta ln o 3 db c hanne l cm 3 16 32 48 64 80 96 112 128

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ta l/N o= -3 [dB ] C hanne l = CM 3 0 16 32 48 64 80 96 112 128 -400 -300 -200 -100 0 100 200 300 No can be estimated Echip and Io.multipath can be estimated
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May 2003 doc.: IEEE 802.15-03137r3 Submissio n Fujita, et al, Sony Corp., Sony Electronics Slide 24 Signal Detection Index Cumulative Distribution AWGN CM1 CM2 CM3 CM4 NoiseOnly Trial = 1000 -10 -8 -6 -4 -2 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 SIGNAL DETECTION INDEX BY CSS Threshold can be clearly determined. (Note: Success of Signal Detection means success of Sync detection) Signal Detection Index(SDI) is calculated from Channel Snap Shot Results SDI=10log(Signal Energy /Total Energy)
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May 2003 doc.: IEEE 802.15-03137r3 Submissio n Fujita, et al, Sony Corp., Sony Electronics Slide 25 Echip.total/No[dB] Sync Detect Probability AWGN CM1 CM2 CM3 CM4 Trial = 200/plot -20 -15 -10 -5 0 5 10 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 SYNC DETECTION PROB. vs. S/N Lower limit of sync detection performance is obviously below lower limit of link performance. In almost case, signal can be detected below -5[dB] S/N
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May 2003 doc.: IEEE 802.15-03137r3 Submissio n Fujita, et al, Sony Corp., Sony Electronics Slide 26 CODING AND SPREADING K=7/ K=3 Conv RS code (240,244,16) SEL SEL Direct Spread Nss=1,2,,,,20 1[Gchip/ s] Rb=23,,1000[Mbps] Short/ Long Spreading Code Up to 1000[Mbps] Up to 500[Mbps] 250[Mbps] 2parallel K=3 Viterbi 500[Mbps] 4parallel K=3 Viterbi WIDE RANGE BIT RATE From 20[Mbps] to 1000[Mbps] K=3 Viterbi complexity is small and parallel implementation of it enables very high bit rate decoding with acceptable cost
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May 2003 doc.: IEEE 802.15-03137r3 Submissio n Fujita, et al, Sony Corp., Sony Electronics Slide 27 CODING GAIN N o C od ing N o R S V ite rb i(K =7 ) R S (P=16 ) R S (P=16 ) V ite rb i(K =3 ) R S (P=16 ) V ite rb i(K =7 ) N o R S V ite rb i(K =3 ) E b /N o [dB ] 1000 by te P .E .R . -3-2-10123456789101112 0 .001 0 .01 0 .1 1 STRONGEST CODING K=7 Viterbi + RS(240,224,16) K=3 Viterbi + RS is useful 1/16 less complex than K=7 with 0.9[dB] degradation
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May 2003 doc.: IEEE 802.15-03137r3 Submissio n Fujita, et al, Sony Corp., Sony Electronics Slide 28 CODING GAIN IN MULTIPATH CHANNEL Single carrier case, every symbol goes through exactly same channel response. Every Symbol Channel No variance of symbol amplitude. CODING GAIN IS SAME AS THE GAIN IN AWGN CHANNEL. Required Eb/No is still 3.0[dB] in multi-path channel. ( K = 7 Viterbi and RS concatenation ) Generally, symbol amplitude variance ( e.g. by fading ) causes several dB’s degradation of coding performance.
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May 2003 doc.: IEEE 802.15-03137r3 Submissio n Fujita, et al, Sony Corp., Sony Electronics Slide 29 DIGITAL RAKE COMBINER (EXAMPLE) #Input samples and processing is 8-paralleled in actual implementation. NO NEED MULTIPLE RF NO NEED MULTIPLIER 1[Gsps] I/ Q 2[bit] Sample Combining (ADD and rounding) coef 5[bit] Sample 2[bit] Combined Sample 6[bit] Spreading Code 1[bit] Symbol Output Despreading Sample Chip Delay
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May 2003 doc.: IEEE 802.15-03137r3 Submissio n Fujita, et al, Sony Corp., Sony Electronics Slide 30 RAKE COMBINING PERFORMANCE Assumption: Nss=4, K=7 Viterbi + RS ( req.Es/No=-0.3[dB]) a a a , , , , , 1 0 a a a , , , , 1 0 0 2 .
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