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... uniformly distributed on the interval [0, π] and τj is uniformly distributed on the interval [0, Td ] for j = i Also, the data symbols dj,k are assumed to take values +1 and −1 with equal probability ... takes any value in the set {ej(θ+2πk /N ) }, where k ∈ {0, 1, 2, , N − 1} and j + = θ is a constant angle in [0, 2π/N ), N is an even number and N ≤ L ( ) This means that takes any value among the ... Rj,i (τ )]dτ lTc for ≤ lTc ≤ τ ≤ (l+1)Tc ≤ Td The expected values have been computed with respect to the mutually independent random variables φj , τj , dj,−1 and dj,0 for ≤ j ≤ M and j = i We...

Ngày tải lên: 26/01/2014, 14:20

... taking values in the interval [−Tc , Tc ], where Tc is the chip duration Our results are derived as functions of the vector of values of the instantaneous time jitter, and they can be used to obtain ... this type, they are called equivalent A Hadamard matrix has a normal form if the first row and first column contain only 1s The normal form is not unique within an equivalence class (this can be shown ... sequences are obtained by taking all L phases of the sequences in the Gold code, which results in an enlarged set with N = L(L + 2) sequences: see [1] and [5] (The set of Gold codes contains L + sequences.)...

Ngày tải lên: 26/01/2014, 14:20

... efficient utilization of the available mass and power of the spacecraft Higher spectral efficiency is achieved by using multibeam satellite antennas which allow resuse of the available spectrum Also, ... satellites This network is comprised of the space segment containing a number of geostationary satellites and the ground segment containing the Customer Premises Equipment (CPE) and gateway offices ... by multibeam antennas in order to reuse the available spectrum in each beam The frequency division multiple access is achieved by segmenting the available spectrum into frequency bands, each...

Ngày tải lên: 26/01/2014, 14:20

... random variables s[l, m] for ¯ m = 1, 2, , N above Notice that they are equal to the sum of N random variables all with (unconditional) mean and variance + σI The (unconditional) mean and ¯ variance ... their variances are var(II [l]) = ¯(n) var(IQ [l]) These variances are also equal to the normalized (with respect to the received power of the desired signal) variance of the interference at the ... its variance does not change, and that overspreading follows despreading and respreading (see Figures 4.4 and 4.5), ¯(n) the mean of these interference terms is zero and their variances are var(II...

Ngày tải lên: 26/01/2014, 14:20

... Mp The packet arrival process then is given by: Pr[ri (Da (k − 1)) = m] = b(m, N Mp , σp ) ≤ m ≤ N Mp where random variable ri (Da (k − 1)) is the row sum i of the packet arrival matrix in frame ... condition (a) does not hold true after the arrival of any new circuit call, the call will be blocked Similarly, if condition (b) does not hold true after the arrival of a new data packet, the packet will ... slot assignment problem in a Time Multipled Switch (TMS) with the equivalent problem in a CDS, we can make the following observations In each time slot of a TMS, in order to avoid conflict we must...

Ngày tải lên: 26/01/2014, 14:20

... −1 Bit Error Rate (BER) Evaluation BER Evaluation for M-ary PSK SE-CDMA In this section we provide the BER evaluation for an M -ary PSK CDMA system Critical to this evaluation are the statistics ... k∈I (i) Next we evaluate the power for the end-to-end interference In the absence of a ˆ ˆ(b ) phase estimation error, that is, θ (i) ≈ θ (i) or equivalently θi i ≈ θ (bi ) , we obtain for the desired ... power The factor k=i P u which depends on power control is i evaluated in detail in Section 6.3.3 Using these results, we next derive the values of ¯ Is Power of Interference from Single User for...

Ngày tải lên: 26/01/2014, 14:20

... arrive synchronously at the satellite despreaders in order to maintain the orthogonality among users within the beam, as well as among beams That is, the starting time of all orthogonal codes should ... always a receiver available to decode the data in the packet If there are parallel data receivers available (as shown in Figure 7.2-B), then the probability of not finding an available one is Pun ... mean acquisition time E[Tacq ] varies from 0.3 to 1.4 ms, depending on the values of the (Ec /I0 ) (chip energy to interference ratio), L and K The dwell accumulation values γ1 and γ2 are optimized...

Ngày tải lên: 26/01/2014, 14:20

... the Gaussian noise samples n11 (k) are white with unit variance, and complex symbol gain uml (k) has mean E[uml (k)] = s γml K K +1 and variance K+1 where the average SNR for path l of user m ... are given below The value of J is determined from the bandwidth, rate of fading or of Doppler, or in general, from the rate of change of the phenomenon that introduces the uncertainty (and change) ... factor of Jmax /J through smoothing, as we will see next) but still maintains the throughput loss (equal to 1/J) within acceptable values A simple analysis of the SAD technique was presented in reference...

Ngày tải lên: 26/01/2014, 14:20

... for various nonlinear distortions, as well as their effects, are discussed afterwards System performance evaluated by the Gaussian approximation is presented in Section 9.3 Section 9.4 pertains ... [0]B (k3 ) [0]B (k4 ) [0]B (k5 ) [0] cI [n] The detailed derivations are shown in Appendix 9A For the case of QPSK, the following results can be obtained for the I component General results for ... I Q (k) bI [0]2 + bQ [0]2 k=2 The first moment of DI can be obtained similarly 9A.2 Evaluation of the Second Moment To compute the variance, we rewrite the expression of SI (t) in Section 9.2.2...

Ngày tải lên: 26/01/2014, 14:20

... đầu vào chuyển mạch tốc độ cao thực dễ dàng, chuyển mạch hàng đợi đầu vào có tốc độ hoạt động đệm mong muốn, cân xấp xỉ tốc độ cổng Vì vậy, chuyển mạch với chế đệm đầu vào tăng kích thước dễ dàng...

Ngày tải lên: 06/10/2014, 21:45

Ngày tải lên: 15/12/2013, 15:15

Ngày tải lên: 15/12/2013, 15:15

Ngày tải lên: 15/12/2013, 15:15

... nhỏ 512 byte Đối với RIP trường dự trữ tin RIP mã hoá sau: - Routing domain xác định ‘routing deamon’được kết hợp với tin Trong UNIX trường ‘process ID’ Bằng cách sử dụng miền định tuyến, máy chạy ... RIP sau khả dụng nhà quản lý mạng Update: khoảng thời gian lần cập nhật có giá trị mặc định 30s Invalid: khoảng thời gian để sau tuyến không hợp lệ, khoảng thời gian nên lần giá trị update Nó có ... Flush tổng thời gian thực thể định tuyến phải trì bảng định tuyến trước bị loại bỏ Nó phải tổng invalid holddown Giá trị mặc định 240s Sleep time tổng thời gian cập nhật định tuyến Nếu router chấp...

Ngày tải lên: 15/12/2013, 15:15

Ngày tải lên: 15/12/2013, 15:15

... tiêu đề nội dung LSA Nội dung trường gói OSPF theo sau tiêu đề khác phụ thuộc vào loại gói LSA, vai trò gán cho router router link điểm-điểm mạng chia sẻ Sau 20byte tiêu đề LSA trường sau Trường...

Ngày tải lên: 15/12/2013, 15:15

Ngày tải lên: 24/12/2013, 20:15

Ngày tải lên: 24/12/2013, 20:15

Ngày tải lên: 24/12/2013, 20:15

Ngày tải lên: 24/12/2013, 20:15