Hi Ali,
I understand that you would like to understad the MATLAB code snippet that simulates frequency-domain channels for a 2x2 MIMO OFDM system.
The code simulates the frequency-domain channel responses for a 2x2 MIMO system, where there are two transmit and two receive antennas. The channel responses are represented as complex vectors.
The variable HA1 represents the channel response from the first transmit antenna to the first receive antenna across 64 OFDM subcarriers. It is initialized as a complex vector with real and imaginary parts generated from a normal distribution.
HA1 = randn(64,1) + randn(64,1) * i;
% "randn(64,1)" generates a 64x1 vector of normally distributed random numbers.
% "i" denotes the imaginary unit.
The channel response HA1 is normalized to have unit magnitude and then scaled by the square root of the received power Prx. This ensures that the channel has a consistent power level.
HA1 = HA1 ./ abs(HA1) * sqrt(Prx);
% "abs(HA1)" computes the magnitude of each complex element.
% "HA1 ./ abs(HA1)" normalizes the vector to unit magnitude.
% "* sqrt(Prx)" scales the vector to the desired power level.
The variables HB1, HA2, and HB2 are similarly defined for the other channel links:
HB1 represents the channel from the second transmit antenna to the first receive antenna.
HA2 represents the channel from the first transmit antenna to the second receive antenna.
HB2 represents the channel from the second transmit antenna to the second receive antenna.
Each of these channel responses is generated and normalized in the same way as HA1, ensuring that all channels have consistent power levels across the 64 OFDM subcarriers.
Hope this helps!
