Narengerile Mar. 2019
Introduction
This is a brief documentation on the MATLAB implementation of estimating the average channel capacity
using the Mathworks 5G New Radio (NR) clustered delay line (CDL) channel model that is provided in the 5G
Toolbox [1]. The nrCDLChannel System object
TM
implements the CDL model as specified in the 3GPP TR
38.901, in which the CDL-A, CDL-B and CDL-C models are for non-line-of-sight (NLOS) links while the CDL-D
and CDL-E models are for LOS links [2]. In this example, the CDL-A model is implemented assuming NLOS
links. The nrCDLChannel System object
TM
can generate channel coefficients and filter the input signal.
Assumptions
Parameters
Assumptions
Notes
Scenario
Urban macro-cell outdoor
scenario
1. The multipath DS is 200 ns in the simulation.
This value is obtained from the calibration data
of the 3GPP CDL model (Section 7.5 in [2]),
considering the reasonable range of the median
value of DS [4]. The default symbol period in the
Mathworks CDL-A model is 32.55 ns, which is
much smaller than the DS. Hence, the
narrowband hybrid precoding algorithm
proposed in [3] can be adopted for estimating
the channel capacity.
2. The transmit/receive antenna gain is fixed for
different carrier frequencies.
3. The hybrid precoding algorithm is adopted for
estimating the channel capacity at mmWave
frequency bands [3]. In this algorithm, each
radio frequency (RF) precoder at the transmitter
or/and receiver is selected from the
corresponding array response vectors, which
requires the linear independence of the vectors
from all paths. Therefore, for one
departure/arrival angle, two antennas cannot be
cross-polarized (at the same position) to have
the same response vector.
4. A single RF chain is used for transmitting one
data stream.
Transmission type
Downlink, NLOS, single data
stream
Delay spread (DS)
200 nanoseconds (ns)
Antenna array
configuration
BS: Uniform rectangular
array (4 x 4), vertically-
polarized
UE: Uniform rectangular
array (2 x 2), vertically-
polarized
Antenna pattern
Isotropic radiators
Large-scale fading
Path loss effects included
by default
Shadow fading effects
modelled as an optional
feature that can be
switched on/off
Additional
modelling
Oxygen absorption effects
modelled as an optional
feature that can be
switched on/off
Bandwidth
Bandwidth scaling linearly
with the carrier frequency
(𝐵𝑊 = 0.005× 𝐹𝑐 )
Requirements
• MATLAB
• Communications Toolbox
• DSP System Toolbox
• Signal Processing Toolbox
• 5G Toolbox
• Phased Array System Toolbox (used in the writer’s implementation, not required for the CDL channel
model)
