diff --git a/Runtime/Tx/ImuTx.cs b/Runtime/Tx/ImuTx.cs
index 55a6b8c..81409b4 100644
--- a/Runtime/Tx/ImuTx.cs
+++ b/Runtime/Tx/ImuTx.cs
@@ -70,12 +70,16 @@ protected override ProBridge.ProBridge.Msg GetMsg(TimeSpan ts)
                 data.linear_acceleration.y += GaussianNoise.Generate(linearAccelerationNoiseStdDev);
                 data.linear_acceleration.z += GaussianNoise.Generate(linearAccelerationNoiseStdDev);
                 
-                data.orientation.x += GaussianNoise.Generate(orientationNoiseStdDev);
-                data.orientation.y += GaussianNoise.Generate(orientationNoiseStdDev);
-                data.orientation.z += GaussianNoise.Generate(orientationNoiseStdDev);
-                data.orientation.w += GaussianNoise.Generate(orientationNoiseStdDev);
-            }
-            
+                var qNoise = Quaternion.Euler(
+                    GaussianNoise.Generate(orientationNoiseStdDev),
+                    GaussianNoise.Generate(orientationNoiseStdDev),
+                    GaussianNoise.Generate(orientationNoiseStdDev)
+                );
+
+                var orientationWithNoise = data.orientation.FromRos() * qNoise;
+                
+                data.orientation = orientationWithNoise.ToRos();
+            }            
             
             data.angular_velocity = _angularVelocity.ToRos();
             data.linear_acceleration = acceleration.ToRos();
diff --git a/Runtime/Utils/UnitySensors/Scripts/Utils/Noise/GaussianNoise.cs b/Runtime/Utils/UnitySensors/Scripts/Utils/Noise/GaussianNoise.cs
deleted file mode 100644
index 2d40aca..0000000
--- a/Runtime/Utils/UnitySensors/Scripts/Utils/Noise/GaussianNoise.cs
+++ /dev/null
@@ -1,34 +0,0 @@
-// Copyright [2020-2024] Ryodo Tanaka (groadpg@gmail.com) and Akiro Harada
-// SPDX-License-Identifier: Apache-2.0
-
-using System;
-
-namespace UnitySensors.Utils.Noise
-{
-    public class GaussianNoise
-    {
-        private Random _random;
-
-        public GaussianNoise()
-        {
-            _random = new Random(Environment.TickCount);
-        }
-
-        public GaussianNoise(int seed)
-        {
-            _random = new Random(seed);
-        }
-
-        public void Init(int seed)
-        {
-            _random = new Random(seed);
-        }
-
-        public double GetNoise(double sigma = 1.0d)
-        {
-            double rand = _random.NextDouble();
-            double normrand = Math.Sqrt(-2.0d * Math.Log(0.0d)) * Math.Cos(2.0d * Math.PI * rand);
-            return normrand;
-        }
-    }
-}
\ No newline at end of file
diff --git a/Runtime/Utils/UnitySensors/Scripts/Utils/Noise/GaussianNoise.cs.meta b/Runtime/Utils/UnitySensors/Scripts/Utils/Noise/GaussianNoise.cs.meta
deleted file mode 100644
index 25282bf..0000000
--- a/Runtime/Utils/UnitySensors/Scripts/Utils/Noise/GaussianNoise.cs.meta
+++ /dev/null
@@ -1,11 +0,0 @@
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-  serializedVersion: 2
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-  executionOrder: 0
-  icon: {instanceID: 0}
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