p moment stability of solutions to stochastic differential equations driven by g brownian motion abstract this paper is concerned with p moment stability of solutions to stochastic differential equations driven by g brownian motion gsdes by means of the lyapunov function and the ito formula an example is given to illustrate the effectiveness of the obtained results

hybrid arq in multiple antenna slow fading channels performance limits and optimal linear dispersion code design this paper focuses on studying the fundamental performance limits and linear dispersion code design for the mimo arq slow fading channel the optimal average rate of well known harq protocols is analyzed the optimal design of space time coding for the mimo arq channel is discussed information theoretic measures are used to optimize the rate assignment and derive the optimum design criterion which is then used to evaluate the optimality of existing space time codes a different design criterion which is obtained from the error probability analysis of space time coded mimo harq is presented examples are studied to reveal the gain of arq feedback in space time coded mimo systems

stability analysis and design of impulsive control systems with time delay a class of impulsive control systems with time varying delays is considered by establishing an impulsive delay differential inequality we analyze the global exponential stability of the impulsive delay systems and estimate the exponential convergence rate on the basis of the analysis a design procedure of impulsive controller is presented the designed impulsive controller not only can globally exponentially stabilize the time delay systems but also can control the exponential convergence rate of the systems two numerical examples are given to illustrate the effectiveness of the method

low complexity maximum likelihood decoder for four transmit antenna quasi orthogonal space time block code this letter proposes a very low complexity maximum likelihood ml detection algorithm based on qr decomposition for the quasi orthogonal space time block code qstbc with four transmit antennas called the lc ml decoder the proposed algorithm enables the qstbc to achieve ml performance with significant reduction in computational load for any high level modulation scheme

quasi orthogonal time reversal space time block coding for frequency selective fading channels quasi orthogonal space time block codes qo stbcs are a powerful code family designed for more than two transmit antennas in contrast to their orthogonal counterparts designed for the same number of transmit antennas qo stbcs are able to provide full rate transmission rate while original qo stbcs enjoy only a partial diversity the recently proposed rotated versions of qo stbcs achieve the maximum diversity order which is equal to the number of transmit antennas since qo stbcs have been originally proposed for frequency flat fading channels it is a challenging design problem to apply them over frequency selective channels the dispersive nature of such channels results in intersymbol interference which needs to be carefully handled at the receiver in this paper we investigate time domain equalization for qo stbc exploiting the embedded quasi orthogonal structure to design low complexity receivers we also present diversity gains for the proposed scheme through pairwise error probability pep derivation and analysis which are further confirmed by monte carlo simulations

controllability of non linear impulsive stochastic systems in this article we consider the finite dimensional dynamical control systems described by non linear impulsive stochastic differential equations sufficient conditions for the complete and approximate controllability of non linear impulsive stochastic systems are formulated and proved under the natural assumption that the corresponding linear system is appropriately controllable

two designs of space time block codes achieving full diversity with partial interference cancellation group decoding a partial interference cancellation pic group decoding based space time block code stbc design criterion was recently proposed by guo and xia where the decoding complexity and the code rate traeoff is dealt when the full diversity is achieved in this paper two designs of stbc are proposed for any number of transmit antennas that can obtain full diversity when a pic group decoding with a particular grouping scheme is applied at receiver with the pic group decoding and an appropriate grouping scheme for the decoding the proposed stbc are shown to obtain the same diversity gain as the ml decoding but have a low decoding complexity the first proposed stbc is designed with multiple diagonal layers and it can obtain the full diversity for two layer design with the pic group decoding and the rate is up to 2 symbols per channel use with pic sic group decoding the first proposed stbc can obtain full diversity for any number of layers and the rate can be full the second proposed stbc can obtain full diversity and a rate up to 9 4 with the pic group decoding some code design examples are given and simulation results show that the newly proposed stbc can well address the rate performance complexity tradeoff of the mimo systems

a quasi orthogonal space time block code it has been shown that a complex orthogonal design that provides full diversity and full transmission rate for a space time block code is not possible for more than two antennas previous attempts have been concentrated in generalizing orthogonal designs which provide space time block codes with full diversity and a high transmission rate we design rate one codes which are quasi orthogonal and provide partial diversity the decoder of the proposed codes works with pairs of transmitted symbols instead of single symbols

on the relation of ostbc and code rate one qstbc average rate ber and coding gain recently the statistical properties of the equivalent channel representation of a multiple input multiple output mimo system employing code rate one quasi orthogonal space time block codes qstbc which are constructed by using orthogonal space time block codes ostbc as building elements was characterized based on these characterizations we analyze the average rate or mean mutual information the bit error rate performance and the coding gain achieved with qstbc for any number of receive and nt 2n n ges 2 transmit antennas first we study constellation rotation using a systematic approach in order to maximize the coding gain and to achieve full diversity qstbc moreover we present an upper bound on the coding gain we derive a lower and upper bound on the ber performance for qstbc furthermore we analyze the average rate achievable with qstbc in case of an uninformed transmitter and also the case in which the transmitter knows the mean channel matrix whereas the receiver has perfect csi along with the analysis we compare all the results of these performance measures with the results achieved with ostbc revealing important connections between ostbc and qstbc for example the coding gain of a qstbc is upper bounded by the coding gain of the underlying ostbc also the ber of a qstbc for nt transmit and nr receive antennas is tightly lower bounded by the ber of a full diversity providing intersymbol interference free system in addition to that we show that gains in terms of average rate by using a qstbc and thus with higher nt instead of the underlying ostbc are only attainable if the available channel state information at the transmitter csit is utilized finally we illustrate our theoretical results using numerical simulations

lyapunov type conditions and stochastic differential equations driven by g brownian motion abstract this paper studies the solvability and the stability of stochastic differential equations driven by g brownian motion gsdes in particular the existence and uniqueness of the solution for locally lipschitz gsdes are obtained by localization methods also the stability of such gsdes is discussed with lyapunov type conditions

almost sure and moment asymptotic boundedness of stochastic delay differential systems abstract the purpose of this article is to investigate the almost sure and moment asymptotic boundedness for a class of stochastic delay differential systems using stochastic analysis techniques a generalized non autonomous l operator delay differential inequality including cross item is presented based on the obtained inequality some sufficient verifiable criteria for the almost sure and moment asymptotic boundedness of the considered systems are derived analytically two numerical examples are given to illustrate the effectiveness of our theoretical results

determination of the steady state response of viscoelastically corner point supported rectangular specially orthotropic plates under the effect of sinusoidally varying moment abstract vibration of orthotropic rectangular plates having viscoelastic point supports at the corners under the effect of sinusoidally varying concentrated moment is analyzed the lagrange equation is used to examine the free vibration characteristics and the steady state response to a sinusoidally varying concentrated moment acting at the centre of a viscoelastically point supported orthotropic elastic plate of rectangular shape in the study for applying the lagrange equation the trial function denoting the deflection of the plate is expressed in the polynomial form by using the lagrange equation the problem is reduced to the solution of a system of algebraic equations the influence of the mechanical properties and of the damping of the supports on the mode shapes and the steady state response of the viscoelastically point supported rectangular plates is investigated numerically for a concentrated moment at the centre for various values of the mechanical properties which characterize the anisotropy of the plate material and for various damping ratios the results of the natural frequencies are given for the first three antisymmetrical symmetrical modes and the steady state responses to a sinusoidally varying concentrated moment are determined for the frequency ranges of the first two antisymmetrical symmetrical mode types convergence studies are made the validity of the obtained results is demonstrated by comparing them with other solutions for free vibration analysis of point supported or completely free rectangular plates for the first three antisymmetrical symmetrical vibration modes based on the kirchhoff love plate theory

on training optimization for estimation of correlated mimo channels in the presence of multiuser interference in this paper the problem of estimating multiple input multiple output mimo channels in a realistic environment involving correlated channel fading and multiuser interference is considered four estimation schemes are studied including the linear minimum mean squared error lmmse least squares ls and gauss markov gm estimators as well as a novel scheme which is derived here as an alternative to lmmse estimation the mse optimal training sequences for each of them are provided and their requirements for side information feedback are assessed the new scheme is shown to exhibit a performance comparable to or even better than lmmse at a significantly lower feedback and computational cost the analytical comparison of the estimation schemes is supported by numerous simulation results that cover a wide range of antenna configurations relative interference power and channel correlation strengths the results of this paper provide a complete picture for a palette of estimation schemes with their relative performance and costs of training

capacity approaching space time codes for systems employing four transmitter antennas the design of space time codes that are capable of approaching the capacity of multiple input single output miso antenna systems is a challenging problem yet one of high practical importance while a remarkably simple scheme of alamouti 1998 is capable of attaining the channel capacity in the case of two transmitter and one receiver antennas 2 1 no such schemes are known for the case of more than two transmitter antennas we propose a family of space time codes that are especially designed for the case of four transmitter antennas and that are shown to allow the attainment of a significant fraction of the open loop shannon capacity of the 4 1 channel

attracting and invariant sets for a class of impulsive functional differential equations in this article a class of nonlinear and nonautonomous functional differential systems with impulsive effects is considered by developing a delay differential inequality we obtain the attracting set and invariant set of the impulsive system an example is given to illustrate the theory

multi valued stochastic differential equations driven by g brownian motion and related stochastic control problems abstractin this paper we prove the existence and uniqueness of a solution for a class of multi valued stochastic differential equations driven by g brownian motion msdeg by means of the yosida approximation method moreover we set up an optimality principle of stochastic control problem and prove the value function of the control problem is the unique viscosity solution of a class of nonlinear partial differential variational inequalities

on channel orthogonalization using space time block coding with partial feedback orthogonal space time block codes ostbcs yield full diversity gain even while requiring only a linear receiver such full rate rate one orthogonal designs are available for complex symbol constellations only for n 2 transmit antennas in this paper we propose a new family of full rate space time block codes stbcs using a single parameter feedback for communication over rayleigh fading channels for n 3 4 transmit antennas and m receive antennas the proposed rate one codes achieve full diversity and the performance is similar to maximum receiver ratio combining the decoding complexity of these codes are only linear even while performing maximum likelihood decoding the partial channel information is a real phase parameter that is a function of all the channel gains and has a simple closed form expression for n 3 4 this feedback information enables us to derive channel orthogonal designs starting from quasi orthogonal stbcs the feedback complexity is significantly lower than conventional closed loop transmit beamforming we compare the proposed codes with the open loop ostbcs and also with the closed loop equal gain transmission egt scheme which uses equal power loading on all antennas simulated error rate performances indicate that the proposed channel orthogonalized stbcs significantly outperform the open loop orthogonal designs for the same spectral efficiency moreover even with significantly lower feedback and computational complexity the proposed scheme outperforms the egt technique for m n

single symbol ml decoding for orthogonal and quasi orthogonal stbc in clipped mimo ofdm systems using a clipping noise model with gaussian approximation an efficient way to reduce the peak to average power ratio papr in ofdm systems is clipping after the clipping in an mimo ofdm system the additive noise may not be white in this paper we develop fast single symbol ml decoding algorithms for orthogonal space time block codes ostbc and linearly transformed quasi orthogonal space time block codes qostbc in clipped mimo ofdm systems by using a clipping noise model with gaussian approximation by using the statistics of the clipping distortions our newly developed fast ml decoding algorithms improve the performance for clipped mimo ofdm systems with ostbc and qostbc while the decoding complexities are not increased simulation results are presented to illustrate the improvement

quasi sure exponential stability and stabilisation of stochastic delay differential equations under g expectation framework in this work we obtain the sufficient conditions to examine quasi sure exponential stability of stochastic delay differential equation under g expectation framework in short g sdde our argumen

p attracting and p invariant sets for a class of impulsive stochastic functional differential equations in this paper a nonlinear and nonautonomous impulsive stochastic functional differential equation is considered by establishing an l operator differential inequality and stochastic analysis technique we obtain the p attracting set and p invariant set of the impulsive stochastic functional differential equation an example is also discussed to illustrate the efficiency of the obtained results

on full diversity space time block codes with partial interference cancellation group decoding in this paper we propose a partial interference cancellation pic group decoding strategy scheme for linear dispersive space time block codes stbc and a design criterion for the codes to achieve full diversity when the pic group decoding is used at the receiver a pic group decoding decodes the symbols embedded in an stbc by dividing them into several groups and decoding each group separately after a linear pic operation is implemented it can be viewed as an intermediate decoding between the maximum likelihood ml receiver that decodes all the embedded symbols together i e all the embedded symbols are in a single group and the zero forcing zf receiver that decodes all the embedded symbols separately and independently i e each group has and only has one embedded symbol after the zf operation is implemented the pic group decoding provides a framework to adjust the complexity performance tradeoff by choosing the sizes of the information symbol groups our proposed design criterion group independence for the pic group decoding to achieve full diversity is an intermediate condition between the loosest ml full rank criterion of codewords and the strongest zf linear independence condition of the column vectors in the equivalent channel matrix we also propose asymptotic optimal ao group decoding algorithm which is an intermediate decoding between the mmse decoding algorithm and the ml decoding algorithm the design criterion for the pic group decoding can be applied to the ao group decoding algorithm because of its asymptotic optimality it is well known that the symbol rate for a full rank linear stbc can be full i e nt for nt transmit antennas it has been recently shown that its rate is upper bounded by 1 if a code achieves full diversity with a linear receiver the intermediate criterion proposed in this paper provides the possibility for codes of rates between nt and 1 that achieve full diversity with the pic group decoding this therefore provides a complexity performance rate tradeoff some design examples are given

finite time h reliable control for t s fuzzy systems with variable sampling abstract this work mainly concentrates on the finite time h reliable control for t s fuzzy systems with aperiodic sampling by considering the information of the state an improved lyapunov krasovskii functional lkf is structured moreover based on free weighted method and aperiodic sampling techniques further criteria are proposed to guarantee that the t s fuzzy systems is finite time stabilization with h performance meanwhile the h reliable controller is designed with larger sampling interval finally the advantages of the obtained results are affirmed by a truck trailer system

boundedness and stability analysis for impulsive stochastic differential equations driven by g brownian motion abstractin this article the pth moment globally exponential ultimate boundedness pth moment globally exponential stability quasi sure globally exponential boundedness and quasi sure globally exponential stability are investigated for impulsive stochastic differential equations driven by g brownian motion using g lyapunov function methods and inequality techniques some sufficient conditions are derived for the boundedness and stability comparing with the existing methods the obtained results allow the corresponding impulse free systems to be unstable and unbounded an example is provided to show the effectiveness of the theoretical results

global exponential stability of impulsive delay difference equation abstract in this paper an impulsive delay difference equation is considered by establishing an impulsive delay difference inequality and using the properties of cone and eigenspace of the spectral radius of nonnegative matrices some new sufficient conditions for global exponential stability of the impulsive delay difference equation are obtained the results extend and improve the earlier publications an example is given to demonstrate the effectiveness of the theory