tailieunhanh - Space-Time Coding phần 3

√ biểu thị các giá trị từ chúng tôi Bằng cách thay thế các λi mục trong (), chúng tôi nhận được cho ri nhận được các thành phần tín hiệu )giá trị riêng yếu tố đó bằng bình phương khoảng cách Euclide giữa hai không gian-thời gian biểu tượng xt và xt. | Effect of System Parameters and Antenna Correlation on the Capacity of MIMO Channels 39 where b1 and b2 are the channel coefficients corresponding to the first and second receive antennas respectively. Thus the received signal vector at the right hand side of the keyhole can be written as r gH2H1x In we can identify the equivalent channel matrix denoted by H as gH2H1. It is given by H g a1b1 a1b2 a2b1 a2b2 The rank of this channel matrix is one and thus there is no multiplexing gain in this channel. The capacity is given by c log2C 1P where 1 is the singular value of the channel matrix H and is given by 1 g2 a2 a2 b2 b2 MIMO Correlation Fading Channel Model with Transmit and Receive Scatterers Now we focus on a MIMO fading channel model with no LOS path. The propagation model is illustrated in Fig. . We consider a linear array of nR receive omnidirectional antennas and a linear array of nT omnidirectional transmit antennas. Both the receive and transmit antennas are surrounded by clutter and large objects obstructing the LOS path. The scattering radius at the receiver side is denoted by Dr and at the transmitted side by Dt. The distance between the receiver and the transmitter is R. It is assumed to be much larger than the scattering radii Dr and Dt. The receive and transmit scatterers are placed at the distance Rr and Rt from their respective antennas. These distances are assumed large enough from the antennas for the plane-wave assumption to hold. The angle spreads at the receiver denoted by ar and at the transmitter denoted by at are given by ar 2 tan-1 Dr Rr at 2 tan-1 Dr Rt Let us assume that there are s scatterers surrounding both the transmitter and the receiver. The receive scatterers are subject to an angle spread of as 2 tan-1 Dr R The elements of the correlation matrix of the received scatterers denoted by S depend on the value of the respective angle spread as. The signals radiated from the .