Wireless Future - Telenor

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Figure 8 As in Figure 5, but with Fpin = 0.01 46 Thus there seem to be possibilities of going up to 10–20 GHz for the mobile links if the adaptive arrays can be made economically feasible. Parallel Channels As already observed by Winters [2] the rich scattering environment may be utilised by having multiple channels. It is apparent from Figure 3 which shows 4 channels, 3 good ones with diversity gain and one bad one, worse than Rayleigh. It may be shown that the total capacity, or spectral efficiency in bits/s/Hz, may be given approximately by the following expression (Andersen [4]) � C = N log2 1+ (15) with P being the signal-to-noise ratio for one antenna. It is assumed that M and N are large, and M > N. The formula may be simply interpreted as N parallel channels, each with power P/N and gain M. This is the ideal case of totally uncorrelated signals at the antennas, but it has this interesting aspect that there is in principle no upper limit to the data rate achievable over a given bandwidth for an infinite number of uncorrelated paths. The two-screen model is a good model for testing these assumptions. Reviewing the four cases again it is noted that cases a), b), and c) all have only one channel or one eigenvalue of any significant value, since MP � N 12 10 8 6 4 2 0 -2 -4 either Fcor or Fpin or both are small. Only case d) offers the high capacity. The two 4-element arrays will again be used as examples. Figure 7 shows the case of Fpin =10 (highly interactive screens) as a function of Fcor. The SNR equals 10 dB, and the figure shows the mean number of active channels, N channel , the gain in dB of the best channel at the 10 % level, and the mean capacity in b/s/Hz. At the left side of Figure 7 where Fcor is small, there is only one channel, no diversity gain and the basic capacity of 7 b/s/Hz for the one channel with 12 dB mean gain. In this region there is no reason to spread the signal over the antennas since there is only one channel. At the right side we get the four channels with some diversity gain, and the capacity increases to 11 b/s/Hz. The crossover point is between values of Fcor of 0.1 and 1. Figure 8 represents the pinhole effect with Fpin = 0.01. A moderate increase in capacity with maximally 2 channels, but a fair diversity gain since the –4 dB at the left derives from the double-Rayleigh. Effect of Polarization In this section the case of dual polarized antennas is briefly discussed. This is especially pertinent for a small number of antenna elements, since the adaptive techniques ensure two inde- Single polarized, Fpin=0.01 Capacity Gain 10% Nchannel -6 10 -2 10 -1 10 0 10 1 Fcor Telektronikk 1.2001
pendent channels even for low angular spread (low values of Fcor). We have here assumed an average cross-polarization level of –10 dB. In order to make a fair comparison there are two dual polarized elements. The result is shown in 12 10 8 6 4 2 0 -2 -4 Telektronikk 1.2001 Figures 9 and 10 corresponding to Figures 7 and 8. The number of channels never drops below 2 as expected, and the capacity is now much less dependent on Fcor or the angular spread. Dual polarized, Fpin=10 Gain 10% -6 10 -2 10 -1 10 0 10 1 Fcor 12 10 8 6 4 2 0 -2 -4 Dual polarized, Fpin=0.01 Capacity Nchannel Capacity Nchannel Gain 10% -6 10 -2 10 -1 10 0 10 1 Fcor Figure 9 Two 2-element dual polarized arrays with Fpin = 10 Figure 10 Two 2-element dual polarized arrays with Fpin = 0.01 47
Page 2 and 3: Telektronikk Volume 97 No. 1 - 2001
Page 4 and 5: Per Hjalmar Lehne (42) obtained his
Page 6 and 7: Stein Svaet (41) is Senior Research
Page 8 and 9: Pbit/day 6 150 125 100 75 50 25 0 F
Page 10 and 11: 8 Video communication as a utility
Page 12 and 13: 10 The idea of reconfigurable mobil
Page 14 and 15: 12 Switched lobe Dynamically phased
Page 16 and 17: Figure 10 The All IP vision Figure
Page 18 and 19: 16 The IP world has some problems t
Page 20 and 21: 18 Abbreviations and acronyms less
Page 22 and 23: Jorge Pereira (40) obtained his Eng
Page 24 and 25: (Millions) Figure 1 Exponential gro
Page 26 and 27: 24 Defining Generation based upon D
Page 28 and 29: Multi-mode Terminal by Software Rad
Page 30 and 31: distribution layer possible return
Page 32 and 33: 30 A Co-Ordinated Approach to 4G As
Page 34 and 35: Figure 2 Applications will grow fas
Page 36 and 37: Figure 5 Evolution from multi-mode
Page 38 and 39: Operator/Provider download librarie
Page 40 and 41: Radio network subsystem - service c
Page 42 and 43: Dr. Techn. Jørgen Bach Andersen (6
Page 44 and 45: Figure 3 Two arrays with M and N el
Page 46 and 47: Figure 5 Cumulative probability dis
Page 50 and 51: 48 Conclusion The challenge of prov
Page 52 and 53: 50 models are described simply by a
Page 54 and 55: 52 ping intervals or “quantizatio
Page 56 and 57: Figure 3 ASE as a function of the a
Page 58 and 59: 56 7 Conclusion and Further Researc
Page 60 and 61: Dave Wisely (39) graduated in 1982
Page 62 and 63: Figure 2 Business case study Figure
Page 64 and 65: Figure 6 BRAIN QoS architecture 62
Page 66 and 67: 64 4 BRAIN homepage. (2001, March 6
Page 68 and 69: Figure 2 The Bluetooth protocol sta
Page 70 and 71: Figure 5 A Bluetooth radio module i
Page 72 and 73: 70 • Instant postcard: A Bluetoot
Page 74 and 75: 72 work visions come true, it is ne
Page 76 and 77: Table 1 Allocated HiperLAN bands (i
Page 78 and 79: Figure 4 Basic MAC frame structure
Page 80 and 81: 78 Preamble BCH FCH ACHs Preamble S
Page 82 and 83: throughput bit/s 80 3 2.5 2 1.5 1 0
Page 84 and 85: 82 5 References 1 CEPT. ERC Decisio
Page 86 and 87: 84 IETF Internet Engineering Task F
Page 88 and 89: Figure 2-3 Mobile IPv6 architecture
Page 90 and 91: 88 domain, it attaches to a new lea
Page 92 and 93: 90 Domain GFA/MAP Figure 3-3 Archit
Page 94 and 95: Geir Gylterud (35) is Research Scie
Page 96 and 97: 94 Framework Resource Resource Int
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Figure 6 SCSs and network functiona
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Figure 9 The new business model. Fr
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100 A strong consortium backs up th
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102 Music Company Figure 3 Service
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Figure 4 OSA architecture service c
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Do van Thanh (43) obtained his MSc
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Figure 2 The first use case diagram
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110 Box 1 - The Open Service Archit
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112 X:User 1:Device 2:Device 3:Devi
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Figure 10 Initiating call from PSTN
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Figure 13 Splitting the incoming st
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Figure 17 A set of communication de
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120 Box 3 continued Session Descrip
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Figure 21 A laptop and peripheral d
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124 Box 4 - Bluetooth Bluetooth is
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126 6 The ICEBERG project. (2001, M
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128 new door towards the upcoming f
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? Figure 1 The Mobile Service Platf
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Figure 2 Needs and Related Services
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134 Telektronikk 1.2001
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136 Telektronikk 1.2001
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Anne Lise Lillebø (52) is Adviser
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140 with other SDOs (Standards Deve
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142 Box 2 - ETNO Declaration We, th
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Arve Meisinset (52) is Senior Resea
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146 In ITU-T we have seen needs to
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148 Each viewpoint constitutes a se
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Figure 2 UML class diagrams for tra
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152 The functionality describing th
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154 9 Potter, B et al. An introduct
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