R. T. Compton, Adaptive Antennas: Concepts and Performance, PrenticeHall, 1988.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....(i) WU,1 (i) W 1,A (i) WU,A (i) # , 5) the transmitted signal vector S(i) can be expressed as S(i) W (i)R(i) 6) where H represents the Hermitian transpose. It is well known that with channel state information, the optimal weight matrix W(i) can be computed by [12] W(i) H(i)H (i) # I] 1 H(i) 7) where I is an A identity matrix. Other assumptions for the system are summarized here. The channels between any antenna pairs are uncorrelated, and signals from different users are independent. Furthermore, the number of simultaneous users is no greater ....

....and coding scheme. With antenna array, it is also affected by the number of antenna elements and the number of simultaneous users. From the system viewpoint, the number of antenna elements at the BS is fixed. Therefore, P b is influenced by the number of simultaneous users U . It is known [12] that an A element array has A 1 degrees of freedom. The cancellation of CCI for one user costs one degree of freedom. When there are U users, U 1 degrees of freedom are dedicated for CCI cancellation, and the remaining A degrees of freedom are for diversity. Apparently, the level of ....

R. T. Compton, Adaptive Antennas: Concepts and Performance, PrenticeHall, 1988.

....W is adjusted in such a way that it receives a single signal and suppresses the interference and the other multipath signals. Thus, we have (3) where [ H denotes a complex conjunction followed by a transposition. The weight vector W can be calculated by Recursive Least Squares (RLS) algorithm [7]. The optimal weight vector W , i.e. the optimal weight vector for the kth path signal, is said to be found when the mean squared error (MSE) of e (refer to Eq. 4) reaches its minimum value. Now, we describe how the weight vectors are determined in the meanwhile of detecting the frame timing of ....

R. T Compton, Adaptive Antenna-Concepts and Performance, Prentice Hall, Englewood Cliffs, 1988.

....array signal processing available to the interested reader. The references listed below are good starting points because of their tutorial nature and their extensive bibliographies: ffl general books [161, 311, 185] ffl connections with spectral analysis [197, 382] ffl adaptive beamforming [77, 440] ffl applications to radar systems [104, 163] ffl subspace methods [299, 34, 214] ffl applications in communications [298, 396, 306] A WWW link to the author of the above section: http: www.ee.byu.edu swindle 13 SSAP with Computational Acoustic and Electromagnetic Propagation Models ....

R. T. Compton, Adaptive Antennas -- Concepts and Performance, Prentice Hall, Inc., Englewood Cliffs, NJ, 1988.

....additionally generate multiple beams [3] and also have low multipath effects. The subject of this report is to study an array of axial, 2 electric dipoles in presence of a conducting circular cylinder for applications to wireless systems. Adaptive array antennas have been studied earlier [4] [6]. Adaptivity of antennas is realized by placing nulls in the direction of any jamming or interfering signal [6] This amounts to change in overall pattern. Successful performance of a wireless system depends on the agility of the antenna to adapt to the environment or link topology. It has been ....

....to study an array of axial, 2 electric dipoles in presence of a conducting circular cylinder for applications to wireless systems. Adaptive array antennas have been studied earlier [4] 6] Adaptivity of antennas is realized by placing nulls in the direction of any jamming or interfering signal [6]. This amounts to change in overall pattern. Successful performance of a wireless system depends on the agility of the antenna to adapt to the environment or link topology. It has been shown that independent control of amplitude and phase excitation [7] 9] can help realizing antenna designs which ....

[Article contains additional citation context not shown here]

R. C. Compton, Adaptive Antennas: Concepts and Performance, Prentice Hall, Englewood Cliffs., NJ, USA, 1988

....and r i is the i:th symbol of the reference signal. The two first symbols of the 26 symbol DCS 1800 training sequence are for practical reasons not used, i.e. N=24. Using these estimates to calculate the weights is known as the SMIalgorithm. The optimum weight vector is given by w = R 1 p [6]. The estimated optimal weight vector would therefore be # # # w R p = 1 , which is solved in the DSP by Gaussian elimination with backsubstitution. This method is both faster and more accurate than calculating the inverse of the covariance matrix and applying it to the steering vector [7] ....

R.T. Compton, "Adaptive Antennas, Concepts and Performance", Prentice-Hall, Engelwood Cliffs, New Jersey, 1988.

....aperture. Beamforming techniques have been widely used up to the present, primarily because they are simple and computationally efficient. Improvements have been made over the years to the original DS approach (see esp. 1, 2] and adaptive implementations have been extensively studied (e.g. [3, 4, 5]) To shape the response of the array, some approaches have made use of the fact that, for a linear array, the DS and weighting operations are equivalent to a windowed discrete Fourier transform (DFT) in the spatial dimension. Although providing a link with the well developed theory of time domain ....

R. T. Compton, Adaptive Antennas -- Concepts and Performance, Prentice Hall, Inc., Englewood Cliffs, NJ, 1988.

....bound. 1 Introduction There are a number of communications applications where, at least for brief periods of time, the signals transmitted over the channel are known prior to reception. These signals are typically used as training sequences for initializing adaptive equalizers [1] or beamformers [2, 3], or for reacquiring synchronization with the individual sources. Known signals are embedded in many of the currently available mobile cellular radio communications formats (e.g. GSM, IS 95, IS 136, etc. and have been also proposed for ALOHA based packet radio systems [4, 5] Recently, Li et ....

R. T. Compton, Adaptive Antennas -- Concepts and Performance, Prentice Hall, Inc., Englewood Cliffs, NJ, 1988.

.... wavelength, d is given by d = sin( d ) 34) The transient behavior of the weights is from equation (21) in this case N = 2 W(t) C 1 e C 2 e A d R d (35) The C 1 and C 2 are vector constants given by the initial weights, W (0) and then they can be found by [2] (36) In simulation, all parameters are set in the following, k = A d = R = 1 (37) d = 50 (38) s 9 d x 2 x 1 i INTERFERENCE Fig. 2. Two element array with desired signal and interference. 2.5 5 30 210 60 240 90 ....

R. T. Compton, Jr., Adaptive Antennas:Concepts and Performance, Prentice Hall, 1988.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC