From e23679431063b42a091f515cec3da3f381b5277b Mon Sep 17 00:00:00 2001
From: Roberto Louro Magueta <rmagueta@allbesmart.pt>
Date: Fri, 29 Apr 2022 01:22:33 +0100
Subject: [PATCH] Put in ulsim a channel matrix H_awgn_mimo different from
 identity (it is a matrix equal to matrix used in dlsim)

---
 openair1/SIMULATION/NR_PHY/ulsim.c | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/openair1/SIMULATION/NR_PHY/ulsim.c b/openair1/SIMULATION/NR_PHY/ulsim.c
index 6521324bec..b64b4c22c5 100644
--- a/openair1/SIMULATION/NR_PHY/ulsim.c
+++ b/openair1/SIMULATION/NR_PHY/ulsim.c
@@ -1260,23 +1260,19 @@ int main(int argc, char **argv)
         for (i=0; i<slot_length; i++) {
           for (ap=0; ap<frame_parms->nb_antennas_rx; ap++) {
             if (channel_model == AWGN) {
-              double H_awgn[4][4] ={{1.0, 0.0, 0.0, 0.0},//rx 0
-                                    {0.0, 1.0, 0.0, 0.0},  //rx 1
-                                    {0.0, 0.0, 1.0, 0.0},  //rx 2
-                                    {0.0, 0.0, 0.0, 1.0}};//rx 3
-              #if 0
-              double H_awgn_mimo[4][4] ={{1.0, 0.5, 0.25, 0.125},//rx 0
-                                   {0.5, 1.0, 0.5, 0.25},  //rx 1
-                                   {0.25, 0.5, 1.0, 0.5},  //rx 2
-                                   {0.125, 0.25, 0.5, 1.0}};//rx 3
-              #endif
+
+              double H_awgn_mimo[4][4] ={{1.0, 0.2, 0.1, 0.05},   //rx 0
+                                         {0.2, 1.0, 0.2, 0.1},    //rx 1
+                                         {0.1, 0.2, 1.0, 0.2},    //rx 2
+                                         {0.05, 0.1, 0.2, 1.0}};  //rx 3
+
               // sum up signals from different Tx antennas
               r_re[ap][i] = 0;
               r_im[ap][i] = 0;
              
               for (int aa=0; aa<n_tx; aa++) {
-                r_re[ap][i] += s_re[aa][i]*H_awgn[ap][aa];
-                r_im[ap][i] += s_im[aa][i]*H_awgn[ap][aa];
+                r_re[ap][i] += s_re[aa][i]*H_awgn_mimo[ap][aa];
+                r_im[ap][i] += s_im[aa][i]*H_awgn_mimo[ap][aa];
               }
             }