@月冷大等 Scope considered Assumption:the electromagnetic waves are considered to propagate along multiple specular paths. For parameter estimation,the parameters describing a path may include its delay,direction of arrival (i.e.azimuth and elevation of arrival),direction of departure (i.e.azimuth and elevation of arrival),Doppler frequency and polarization matrix. Other parameters may be also included,e.g.the time-variability of these parameters in the time-variant case. The bidirection-delay-Doppler-Dual-polarization specular path-model is introduced Graduate course:Propagation Channel Characterization,Parameter Estimation and Modeling 77/199
Scope considered Graduate course: Propagation Channel Characterization, Parameter Estimation and Modeling 77 / 199 ■ Assumption: the electromagnetic waves are considered to propagate along multiple specular paths. ■ For parameter estimation, the parameters describing a path may include its delay, direction of arrival (i.e. azimuth and elevation of arrival), direction of departure (i.e. azimuth and elevation of arrival), Doppler frequency and polarization matrix. ■ Other parameters may be also included, e.g. the time-variability of these parameters in the time-variant case. ■ The bidirection-delay-Doppler-Dual-polarization specular path-model is introduced
@月命大凳 Dual polarization Dual polarization is specifically considered as the polarization of an electromagnetic wave,especially for the TEM waves,can be projected into two orthogonal directions More samples of the channel observation can be obtained to improve the estimation accuracy of the path parameters compared with the signal-polarization Since using dual polarized antenna array for boosting the capacity of MIMO system has been considered in advanced wireless communication standards,modeling the channels in the dual-polarization domain becomes popular. Therefore,it is necessary to design estimation algorithms for extracting the polarization characteristics of the propagation channel. Graduate course:Propagation Channel Characterization,Parameter Estimation and Modeling 78/199
Dual polarization Graduate course: Propagation Channel Characterization, Parameter Estimation and Modeling 78 / 199 ■ Dual polarization is specifically considered as the polarization of an electromagnetic wave, especially for the TEM waves, can be projected into two orthogonal directions ■ More samples of the channel observation can be obtained to improve the estimation accuracy of the path parameters compared with the signal-polarization ■ Since using dual polarized antenna array for boosting the capacity of MIMO system has been considered in advanced wireless communication standards, modeling the channels in the dual-polarization domain becomes popular. ■ Therefore, it is necessary to design estimation algorithms for extracting the polarization characteristics of the propagation channel
@月冷大学 Diagram of Dual polarization channel Contribution of the (th wave to the received signal in a MIMO system incorporating dual-antenna arrays c2.(22) 4(t-t,)o os:(1,0.) C1M(2) Polarization Matrix of C2M2(22) u(t-t) Path exp(j2mv,t) ·s(t0) A uu (1-T)o 0s,(t,0,) c2.12(22) 9.M.2(2) C2,M.2(22) Graduate course:Propagation Channel Characterization,Parameter Estimation and Modeling 79/199
Diagram of Dual polarization channel Graduate course: Propagation Channel Characterization, Parameter Estimation and Modeling 79 / 199 Contribution of the ℓth wave to the received signal in a MIMO system incorporating dual-antenna arrays Polarization Matrix of Path " " A (ȍ ) 1,1,1 ,1 " c ( ) 1 " u t W ( ) 1 " u t W M ( ) " u t W (ȍ ) 1,1,2 ,2 " c ,( ) 1 ș" s t ;( ) ș" exp( j 2 t) s t SX " (ȍ ) 2,1,1 ,1 " c (ȍ ) M1 2,,1 ,1 " c ,( ) 2 ș" s t M (ȍ ) 2,1,2 ,2 " c (ȍ ) M1 1,,1 ,1 " c (ȍ ) ,2 M2 1, ,2 " c (ȍ ) ,2 M2 2, ,2 " c
@月命大凳 Considerations Rx and Tx antenna arrays with dual-polarized antenna configuration considered Each of the dual antenna transmits/receives signal within two polarizations at the same time.This assumption is based on the realistic experience that antennas can not transmit or receive signals in one polarization only. To differentiate the two polarizations in the underlying model,one of them is called main polarization,specifying the dominant direction of the signal field pattern.The other is correspondingly referred to the complementary polarization. Graduate course:Propagation Channel Characterization,Parameter Estimation and Modeling 80/199
Considerations Graduate course: Propagation Channel Characterization, Parameter Estimation and Modeling 80 / 199 ■ Rx and Tx antenna arrays with dual-polarized antenna configuration considered. ■ Each of the dual antenna transmits/receives signal within two polarizations at the same time. This assumption is based on the realistic experience that antennas can not transmit or receive signals in one polarization only. ■ To differentiate the two polarizations in the underlying model, one of them is called main polarization, specifying the dominant direction of the signal field pattern. The other is correspondingly referred to the complementary polarization
@月冷大学 Polarization matrix and signal model Polarization matrix Ae= 00,1,100,1,2 is composed of the a0,21a0,2,2 complex weights for the attenuations along the propagation paths The signal model describing the contribution of the eth wave to the output of the MIMO system reads s(t0e）=exp(j2πvt)[c2,1(22.）c2,2(22.e】Ae [c1,1(21,e）c,2(21,】u(t-T), where Ci.p:(S):the steering vector of the transmitter array (i=1) with totally Mi entries or receiver array (i=2)with totally M2 entries Mi and M2 are the amount of antennas in the Tx and Rx respectively pi,(pi=1,2)denotes the polarization inde Graduate course:Propagation Channel Characterization,Parameter Estimation and Modeling 81/199
Polarization matrix and signal model Graduate course: Propagation Channel Characterization, Parameter Estimation and Modeling 81 / 199 ■ Polarization matrix A ℓ = αℓ, 1,1 αℓ, 1,2 αℓ, 2,1 αℓ, 2,2 is composed of the complex weights for the attenuations along the propagation paths. ■ The signal model describing the contribution of the ℓth wave to the output of the MIMO system reads s ( t; θ ℓ) = exp( j 2πνℓ t ) c 2,1 ( Ω 2,ℓ ) c 2,2 ( Ω 2,ℓ ) A ℓ c 1,1 ( Ω 1,ℓ ) c 1,2 ( Ω 1,ℓ ) T u ( t − τℓ ), where ◆ ci,pi ( Ω ) : the steering vector of the transmitter array ( i = 1) with totally M1 entries or receiver array ( i = 2) with totally M2 entries, ◆ M1 and M2 are the amount of antennas in the Tx and Rx respectively ◆ p i ,( p i = 1, 2) denotes the polarization inde