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Package: comm
Filter input signal through LTE MIMO multipath fading channel
The comm.LTEMIMOChannel System object™ filters an input signal through an LTE multipleinput multipleoutput (MIMO) multipath fading channel.
A specialization of the comm.MIMOChannel System object, the comm.LTEMIMOChannel System objects offers preset configurations for use with LTE link level simulations. In addition to the comm.MIMOChannel System object, the comm.LTEMIMOChannel System object also corrects the correlation matrix to be positive semidefinite, after rounding to 4digit precision. This System object models Rayleigh fading for each of its links.
To filter an input signal using an LTE MIMO multipath fading channel:
Define and set up your LTE MIMO multipath fading channel object. See Construction.
Call step to filter the input signal using an LTE MIMO multipath fading channel according to the properties of comm.LTEMIMOChannel. The behavior of step is specific to each object in the toolbox.
H = comm.LTEMIMOChannel creates a 3GPP Long Term Evolution (LTE) Release 10 specified multipleinput multipleoutput (MIMO) multipath fading channel System object, H. This object filters a real or complex input signal through the multipath LTE MIMO channel to obtain the channel impaired signal.
H = comm.LTEMIMOChannel(Name,Value) creates an LTE MIMO multipath fading channel object, H, with the specified property Name set to the specified Value. You can specify additional namevalue pair arguments in any order as (Name1,Value1,...,NameN,ValueN).
SampleRate 
Input signal sample rate (Hertz) Specify the sample rate of the input signal in hertz as a doubleprecision, real, positive scalar. The default value of this property is 30.72 MHz, as defined in the LTE specification. 
Profile 
Channel propagation profile Specify the propagation conditions of the LTE multipath fading channel as one of EPA 5Hz  EVA 5Hz  EVA 70Hz  ETU 70Hz  ETU 300Hz, which are supported in the LTE specification Release 10. The default value of this property is EPA 5Hz. This property defines the delay profile of the channel to be one of EPA, EVA, and ETU. This property also defines the maximum Doppler shift of the channel to be 5 Hz, 70 Hz, or 300 Hz. The Doppler spectrum always has a Jakes shape in the LTE specification. The EPA profile has seven paths. The EVA and ETU profiles have nine paths. The following tables list the delay and relative power per path associated with each profile. Extended Pedestrian A Model (EPA) 
AntennaConfiguration 
Antenna configuration Specify the antenna configuration of the LTE MIMO channel as one of 1x2  2x2  4x2  4x4. These configurations are supported in the LTE specification Release 10. The default value of this property is 2x2. The property value is in the format of N_{t}byN_{r}. N_{t} represents the number of transmit antennas and N_{r} represents the number of receive antennas. 
CorrelationLevel 
Spatial correlation strength Specify the spatial correlation strength of the LTE MIMO channel as one of Low  Medium  High. The default value of this property is Low. When you set this property to Low, the MIMO channel is spatially uncorrelated. The transmit and receive spatial correlation matrices are defined from this property according to the LTE specification Release 10. See the Algorithms section for more information. 
AntennaSelection 
Antenna selection Specify the antenna selection scheme as one of Off  Tx  Rx  Tx and Rx, where Tx represents transmit antennas and Rx represents receive antennas. When you select Tx and/or Rx, additional input(s) are required to specify which antennas are selected for signal transmission. The default value of this property is Off. 
RandomStream 
Source of random number stream Specify the source of random number stream as one of Global stream  mt19937ar with seed. The default value of this property is Global stream. When you set this property to Global stream, the current global random number stream is used for normally distributed random number generation. In this case, the reset method only resets the filters. If you set RandomStream to mt19937ar with seed, the object uses the mt19937ar algorithm for normally distributed random number generation. In this case, the reset method resets the filters and reinitializes the random number stream to the value of the Seed property. 
Seed 
Initial seed of mt19937ar random number stream Specify the initial seed of an mt19937ar random number generator algorithm as a doubleprecision, real, nonnegative integer scalar. The default value of this property is 73. This property applies when you set the RandomStream property to mt19937ar with seed. The Seed reinitializes the mt19937ar random number stream in the reset method. 
NormalizePathGains 
Normalize path gains (logical) Set this property to true to normalize the fading processes so that the total power of the path gains, averaged over time, is 0 dB. The default value of this property is true. When you set this property to false, there is no normalization for path gains. 
NormalizeChannelOutputs 
Normalize channel outputs (logical) Set this property to true to normalize the channel outputs by the number of receive antennas. The default value of this property is true. When you set this property to false, there is no normalization for channel outputs. 
PathGainsOutputPort 
Enable path gain output (logical) Set this property to true to output the channel path gains of the underlying fading process. The default value of this property is false. 
clone  Create LTEMIMOChannel object with same property values 
getNumInputs  Number of expected inputs to step method 
getNumOutputs  Number of outputs from step method 
isLocked  Locked status for input attributes and nontunable properties 
release  Allow property value and input characteristics changes 
reset  Reset states of the LTEMIMOChannel object 
step  Filter input signal through LTE MIMO multipath fading channel 
This System object is a specialized implementation of the comm.MIMOChannel System object. For additional algorithm information, see the comm.MIMOChannel System object help page.
The following table defines the transmitter eNodeB correlation matrix.
One Antenna  Two Antennas  Four Antennas  

eNodeB Correlation  R_{eNB} = 1 


The following table defines the receiver UE correlation matrix.
One Antenna  Two Antennas  Four Antennas  

UE Correlation  R_{UE} = 1 


The following table describes the R_{spat} channel spatial correlation matrix between the transmitter and receiver antennas.
TxbyRx Configuration  Correlation Matrix 

1by2 

2by2 

4by2 

4by4 

Low Correlation  Medium Correlation  High Correlation  

α  β  α  β  α  β 
0  0  0.3  0.9  0.9  0.9 
To insure the correlation matrix is positive semidefinite after roundoff to 4 digit precision, this System object uses the following equation:
Where
α represents the scaling factor such that the smallest value is used to obtain a positive semidefinite result.
For the 4by2 high correlation case, α=0.00010.
For the 4by4 high correlation case, α=0.00012.
The object uses the same method to adjust the 4by4 medium correlation matrix to insure the correlation matrix is positive semidefinite after rounding to 4 digit precision with α = 0.00012.
[1] 3rd Generation Partnership Project, Technical Specification Group Radio Access Network, Evolved Universal Terrestrial Radio Access (EUTRA), Base Station (BS) radio transmission and reception, Release 10, 2009–2010, 3GPP TS 36.104, Vol. 10.0.0.
[2] 3rd Generation Partnership Project, Technical Specification Group Radio Access Network, Evolved Universal Terrestrial Radio Access (EUTRA), User Equipment (UE) radio transmission and reception, Release 10, 2010, 3GPP TS 36.101, Vol. 10.0.0.
[3] Oestges, C., and B. Clerckx. MIMO Wireless Communications: From RealWorld Propagation to SpaceTime Code Design, Academic Press, 2007.
[4] Correira, L. M. Mobile Broadband Multimedia Networks: Techniques, Models and Tools for 4G, Academic Press, 2006.
[5] Jeruchim, M., P. Balaban, and K. S. Shanmugan. Simulation of Communication Systems, Second Edition, New York, Kluwer Academic/Plenum, 2000.