Recently, space time block codes (STBCs) are proposed for multi-input and multi-output (MIMO) antenna systems. Designing an STBC with both low decoding complexity and non-vanishing property for the Long Term Evolution...Recently, space time block codes (STBCs) are proposed for multi-input and multi-output (MIMO) antenna systems. Designing an STBC with both low decoding complexity and non-vanishing property for the Long Term Evolution Advanced (LTE-A) remains an open issue. In this paper, first our previously proposed STBC’s non-vanishing property will be completely described. The proposed STBC scheme has some interesting properties: 1) the scheme can achieve full rate and full diversity;2) its maximum likelihood (ML) decoding requires a joint detection of three real symbols;3) the minimum determinant values (MDVs) do not vanish by increasing signal constellation sizes;4) compatible with the single antenna transmission mode. The sentence has been dropped. Second, in order to improve BER performance, we propose a variant of proposed STBC. This scheme further decreases the detection complexity with a rate reduction of 33%;moreover, non-vanishing MDVs property is preserved. The simulation results show the second proposed STBC has better BER performance compared with other schemes.展开更多
In this note, the expectation value of time based on quantum mechanics formalism is derived. It is found that the expectation value of time does not depend on space.
Cauchy problem and initial boundary value problem for nonlinear parabolic equation in CB([0,T):L p) or L q(0,T;L p) type space are considered. Similar to wave equation and dispersive wave equation, the space time mean...Cauchy problem and initial boundary value problem for nonlinear parabolic equation in CB([0,T):L p) or L q(0,T;L p) type space are considered. Similar to wave equation and dispersive wave equation, the space time means for linear parabolic equation are shown and a series of nonlinear estimates for some nonlinear functions are obtained by space time means. By Banach fixed point principle and usual iterative technique a local mild solution of Cauchy problem or IBV problem is constructed for a class of nonlinear parabolic equations in CB([0,T); L p) or L q(0,T; L p) with φ(x)∈L r. In critical nonlinear case it is also proved that T can be taken as infinity provided that ‖φ(x)‖ r is sufficiently small, where (p,q,r) is an admissible triple.展开更多
Properties of an operator representing the dynamical time in the extended parameterization invariant formulation of quantum mechanics are studied. It is shown that this time operator is given by a positive operator me...Properties of an operator representing the dynamical time in the extended parameterization invariant formulation of quantum mechanics are studied. It is shown that this time operator is given by a positive operator measure analogously to the quantities that are known to represent various measurable time operators. The relation between the dynamical time of the extended formulation and the best known example of the system time operator, i.e., for the free one- dimensional particle, is obtained.展开更多
In this paper, we present a stochastic model for data in a Wireless Sensor Network (WSN) using random field theory. The model captures the space-time behavior of the underlying phenomenon being observed by the network...In this paper, we present a stochastic model for data in a Wireless Sensor Network (WSN) using random field theory. The model captures the space-time behavior of the underlying phenomenon being observed by the network. We present results regarding the size and spatial distribution of the regions of the network that sense statistically extreme values of the underlying phenomenon using the theory of extreme excursion regions. These results compliment many existing works in the literature that describe algorithms to reduce the data load, but lack an analytical approach to evaluate the size and spatial distribution of this load. We show that if only the statistically extreme data is transmitted in the network, then the data load can be significantly reduced. Finally, a simple performance model of a WSN is developed based on a collection of asynchronous M/M/1 servers that work in parallel. We derive several performance measures from this performance model. The presented results will be useful in the design of large scale sensor networks.展开更多
文摘Recently, space time block codes (STBCs) are proposed for multi-input and multi-output (MIMO) antenna systems. Designing an STBC with both low decoding complexity and non-vanishing property for the Long Term Evolution Advanced (LTE-A) remains an open issue. In this paper, first our previously proposed STBC’s non-vanishing property will be completely described. The proposed STBC scheme has some interesting properties: 1) the scheme can achieve full rate and full diversity;2) its maximum likelihood (ML) decoding requires a joint detection of three real symbols;3) the minimum determinant values (MDVs) do not vanish by increasing signal constellation sizes;4) compatible with the single antenna transmission mode. The sentence has been dropped. Second, in order to improve BER performance, we propose a variant of proposed STBC. This scheme further decreases the detection complexity with a rate reduction of 33%;moreover, non-vanishing MDVs property is preserved. The simulation results show the second proposed STBC has better BER performance compared with other schemes.
文摘In this note, the expectation value of time based on quantum mechanics formalism is derived. It is found that the expectation value of time does not depend on space.
文摘Cauchy problem and initial boundary value problem for nonlinear parabolic equation in CB([0,T):L p) or L q(0,T;L p) type space are considered. Similar to wave equation and dispersive wave equation, the space time means for linear parabolic equation are shown and a series of nonlinear estimates for some nonlinear functions are obtained by space time means. By Banach fixed point principle and usual iterative technique a local mild solution of Cauchy problem or IBV problem is constructed for a class of nonlinear parabolic equations in CB([0,T); L p) or L q(0,T; L p) with φ(x)∈L r. In critical nonlinear case it is also proved that T can be taken as infinity provided that ‖φ(x)‖ r is sufficiently small, where (p,q,r) is an admissible triple.
基金Project supported by the Ministry of Science and Education of the Republic of Serbia (Grant Nos. 171017, 171028, and 171006)
文摘Properties of an operator representing the dynamical time in the extended parameterization invariant formulation of quantum mechanics are studied. It is shown that this time operator is given by a positive operator measure analogously to the quantities that are known to represent various measurable time operators. The relation between the dynamical time of the extended formulation and the best known example of the system time operator, i.e., for the free one- dimensional particle, is obtained.
文摘In this paper, we present a stochastic model for data in a Wireless Sensor Network (WSN) using random field theory. The model captures the space-time behavior of the underlying phenomenon being observed by the network. We present results regarding the size and spatial distribution of the regions of the network that sense statistically extreme values of the underlying phenomenon using the theory of extreme excursion regions. These results compliment many existing works in the literature that describe algorithms to reduce the data load, but lack an analytical approach to evaluate the size and spatial distribution of this load. We show that if only the statistically extreme data is transmitted in the network, then the data load can be significantly reduced. Finally, a simple performance model of a WSN is developed based on a collection of asynchronous M/M/1 servers that work in parallel. We derive several performance measures from this performance model. The presented results will be useful in the design of large scale sensor networks.
