rfsensor parameterization

@rfSensor/RSS.m

@@ -10,6 +10,6 @@ function value = RSS(obj, d, t, a)
     end
     assert(size(d, 1) == size(t, 1), "Mismatch in number of distances (%d) and tilts (%d) provided", size(d, 1), size(t, 1));
 
-    % RSS (dBm) = TX Power (dBm) + TX Antenna Gain (dB) + RX Antenna Gain (dBi) - Path Loss (dB)
+    % RSS (dBm) = TX Power (dBm) + TX Antenna Gain (dBi) + RX Antenna Gain (dBi) - Path Loss (dB)
     value = obj.P_TX_dBm + obj.transmitterGain(t, a) + obj.G_RX_dBi - obj.pathLoss(d);
 end

@rfSensor/initialize.m

@@ -1,26 +1,32 @@
-function obj = initialize(obj, txPower, bandwidth, centerFreq, rxGain_dBi, tilt, azimuth)
+function obj = initialize(obj, txPower, bandwidth, centerFreq, rxGain_dBi, beamwidthExponent, tilt, azimuth, lossExponent)
     arguments (Input)
         obj (1, 1) {mustBeA(obj, "rfSensor")}
         txPower (1, 1) double;
         bandwidth (1, 1) double;
         centerFreq (1, 1) double;
         rxGain_dBi (1, 1) double;
+        beamwidthExponent (1, 1) double;
         tilt (1, 1) double = 0;
         azimuth (1, 1) double = 0;
+        lossExponent (1, 1) double = NaN;
     end
     arguments (Output)
         obj (1, 1) {mustBeA(obj, "rfSensor")}
     end
 
-    % Provided values
+    %% Provided values
     obj.P_TX = txPower; % Transmit power (W)
     obj.BW = bandwidth; % Bandwidth (Hz)
     obj.f_c = centerFreq; % Center frequency (Hz)
     obj.G_RX_dBi = rxGain_dBi; % Receiving Antenna Gain (dBi)
+    obj.beamwidthExponent = beamwidthExponent; % Defines how focused the antenna beam is
+    obj.lossExponent = lossExponent;
+
+    % Define initial antenna pointing
     obj.tilt = tilt;
     obj.azimuth = azimuth;
 
-    % Computed values
+    %% Computed values
     obj.P_TX_dBm = 10*log10(obj.P_TX/1e-3); % Transmit power in dBm
     obj.N = obj.k_B * obj.T_0 * obj.BW; % Thermal noise
 end

@rfSensor/pathLoss.m

@@ -8,6 +8,6 @@ function L_FSPL_dB = pathLoss(obj, d)
     end
 
     % Free Space Path Loss (dB); d clamped away from zero (log undefined at d=0)
-    L_FSPL_dB = 20*log10(max(d, eps)) + 20*log10(obj.f_c) + 20*log10((4*pi)/obj.c);
+    L_FSPL_dB = obj.lossExponent * 10 * log10(max(d, eps)) + 20 * log10(obj.f_c) + 20 * log10((4*pi)/obj.c);
 
 end

@rfSensor/plotParameters.m

@@ -40,7 +40,7 @@ function f = plotParameters(obj)
     end
 
     colormap(turbo);
-    colorbar;
+    c = colorbar; c.Label.String = "Received Signal Strength (dB)";
     daspect([1 1 0.2]);
     xlabel('X (log_{10} units)'); ylabel('Y (log_{10} units)'); zlabel('log_{10} Altitude (m)');
     set(gca, 'ZDir', 'reverse');

@rfSensor/plotPerformance.m

@@ -52,7 +52,7 @@ function f = plotPerformance(obj, altitude, otherSensorsPos, otherSensors)
     colorbar; xlabel("X (m)"); ylabel("Y (m)");
     title("Linearly Normalized SNR (dB)");
     subtitle("No interfering sources");
-    addSensorOverlay(gca, sensorXY, sensorTilts, sensorAzimuths, tailScale);
+    addSensorOverlay(gca, sensorXY(1, 1:2), sensorTilts(1, 1), sensorAzimuths(1, 1), tailScale);
 
     nexttile;
     imagesc(distances, distances, SINR);

@rfSensor/rfSensor.m

@@ -4,6 +4,7 @@ classdef rfSensor
         c = 3e8; % Speed of light (m/s)
         k_B = 1.38e-23 % Boltzmann constant (W/Hz/K) for thermal noise model
         T_0 = 300; % Ambient temperature (Kelvin) for thermal noise model
+        lossExponent = NaN; % Path loss exponent (2 for free space, up to 6 for the lossiest environments)
         % Sensor parameters
         P_TX = NaN; % Transmit power (Watts)
         BW = NaN; % Bandwidth (Hz)
@@ -11,6 +12,7 @@ classdef rfSensor
         G_RX_dBi = NaN; % Receiver antenna gain
         tilt = NaN;     % Antenna boresight tilt (deg): 0=nadir, 90=horizon
         azimuth = NaN;  % Antenna boresight azimuth (deg): 0=+y, 90=+x, 180=-y, 270=-x
+        beamwidthExponent = NaN; % Antenna beamwidth exponent for cosine radiation pattern, larger exponent -> narrower beam
         % Values computed at initialization
         P_TX_dBm = NaN; % Transmit power (dBm)
         N = NaN; % Thermal noise
@@ -19,7 +21,7 @@ classdef rfSensor
     end
 
     methods (Access = public)
-        [obj] = initialize(obj, txPower, bandwidth, centerFreq, rxGain, tilt, azimuth); % initialize sensor, define parameters
+        [obj] = initialize(obj, txPower, bandwidth, centerFreq, rxGain, beamwidthExponent, tilt, azimuth); % initialize sensor, define parameters
         [SINR, SNR, obj, otherSensors] = sensorPerformance(obj, agentPos, targetPos, otherSensorsPos, otherSensors); % determine sensor performance for a given single sensor and target geometry
         [d, t, a] = computePointToPoints(obj, agentPos, targetPos);
         [value] = halfAngle(obj); % tilt angle (deg) at which sensor performance is halved

@rfSensor/transmitterGain.m

@@ -11,8 +11,6 @@ function value = transmitterGain(obj, t, a)
         error("t and a must be the same size");
     end
 
-    n = 6;   % beamwidth exponent (higher = narrower beam)
-
     % Angular offset from boresight via spherical law of cosines
     % Convention: t=0° nadir, t=90° horizon; a=0° +y, a=90° +x
     cos_theta = sind(obj.tilt) .* sind(t) .* cosd(a - obj.azimuth) + ...
@@ -21,5 +19,5 @@ function value = transmitterGain(obj, t, a)
     theta = acosd(cos_theta);
 
     % Cardioid family: peak at boresight (theta=0), null opposite (theta=180°)
-    value = 10 .* n .* log10((1 + cosd(theta)) ./ 2);
+    value = 10 .* obj.beamwidthExponent .* log10((1 + cosd(theta)) ./ 2);
 end

@sensingObjective/plot.m

@@ -20,7 +20,7 @@ function f = plot(obj, ind, f)
         hold(f.CurrentAxes, "off");
     else
         hold(f.Children(1).Children(ind(1)), "on");
-        o = surf(f.Children(1).Children(ind(1)), obj.X, obj.Y, zeros(size(obj.X)), obj.values ./ max(obj.values, [], "all"), "EdgeColor", "none");
+        o = surf(f.Children(1).Children(ind(1)), obj.X, obj.Y, zeros(size(obj.X)), obj.values ./ sum(obj.values, "all"), "EdgeColor", "none");
         o.HitTest = "off";
         o.PickableParts = "none";
         hold(f.Children(1).Children(ind(1)), "off");

test/test_rfSensor.m

@@ -18,8 +18,10 @@ classdef test_rfSensor < matlab.unittest.TestCase
             BW = 20e6; % Bandwidth (Hz)
             f_c = 2e9; % Center frequency (Hz)
             G_RX_dBi = 3; % Receiving Antenna Gain (dBi)
+            beamwidthExponent = 6;
+            lossExponent = 2;
 
-            tc.testClass = tc.testClass.initialize(P_TX, BW, f_c, G_RX_dBi, 0, 0);
+            tc.testClass = tc.testClass.initialize(P_TX, BW, f_c, G_RX_dBi, beamwidthExponent, 0, 0, lossExponent);
 
             tc.testClass.plotParameters();
         end
@@ -29,8 +31,10 @@ classdef test_rfSensor < matlab.unittest.TestCase
             BW = 20e6; % Bandwidth (Hz)
             f_c = 2e9; % Center frequency (Hz)
             G_RX_dBi = 3; % Receiving Antenna Gain (dBi)
+            beamwidthExponent = 6;
+            lossExponent = 2;
 
-            tc.testClass = tc.testClass.initialize(P_TX, BW, f_c, G_RX_dBi, 30, 135);
+            tc.testClass = tc.testClass.initialize(P_TX, BW, f_c, G_RX_dBi, beamwidthExponent, 30, 135, lossExponent);
 
             altitude = 30;
 
@@ -50,8 +54,10 @@ classdef test_rfSensor < matlab.unittest.TestCase
             BW = 20e6; % Bandwidth (Hz)
             f_c = 2e9; % Center frequency (Hz)
             G_RX_dBi = 3; % Receiving Antenna Gain (dBi)
+            beamwidthExponent = 6;
+            lossExponent = 2;
 
-            tc.testClass = tc.testClass.initialize(P_TX, BW, f_c, G_RX_dBi, 0, 0);
+            tc.testClass = tc.testClass.initialize(P_TX, BW, f_c, G_RX_dBi, beamwidthExponent, 0, 0, lossExponent);
 
             altitude = 30;
             otherSensorsPos = [6, -4, -1]; % relative to main sensor
@@ -67,8 +73,10 @@ classdef test_rfSensor < matlab.unittest.TestCase
             BW = 20e6; % Bandwidth (Hz)
             f_c = 2e9; % Center frequency (Hz)
             G_RX_dBi = 3; % Receiving Antenna Gain (dBi)
+            beamwidthExponent = 6;
+            lossExponent = 2;
 
-            tc.testClass = tc.testClass.initialize(P_TX, BW, f_c, G_RX_dBi, 0, 0);
+            tc.testClass = tc.testClass.initialize(P_TX, BW, f_c, G_RX_dBi, beamwidthExponent, 0, 0, lossExponent);
 
             altitude = 30;
             otherSensorsPos = [6, -4, -1; -2, 6, 0]; % relative to main sensor
@@ -77,8 +85,8 @@ classdef test_rfSensor < matlab.unittest.TestCase
             otherSensors{2} = rfSensor;
 
             % Must use same center frequency and bandwidth for interference sources
-            otherSensors{1} = otherSensors{1}.initialize(10 * P_TX, BW, f_c, G_RX_dBi, 0, 0);
+            otherSensors{1} = otherSensors{1}.initialize(10 * P_TX, BW, f_c, G_RX_dBi, beamwidthExponent, 0, 0, lossExponent);
-            otherSensors{2} = otherSensors{2}.initialize(10 * P_TX, BW, f_c, G_RX_dBi, 0, 0);
+            otherSensors{2} = otherSensors{2}.initialize(10 * P_TX, BW, f_c, G_RX_dBi, beamwidthExponent, 0, 0, lossExponent);
 
             tc.testClass.plotPerformance(altitude, otherSensorsPos, otherSensors);
         end
@@ -88,13 +96,15 @@ classdef test_rfSensor < matlab.unittest.TestCase
             f_c = 2e9;
             G_RX_dBi = 3;
             altitude = 30;
+            beamwidthExponent = [6, 4, 10];
+            lossExponent = 2;
 
             sensor1 = rfSensor;
-            sensor1 = sensor1.initialize(P_TX, BW, f_c, G_RX_dBi, 15, 45);
+            sensor1 = sensor1.initialize(P_TX, BW, f_c, G_RX_dBi, beamwidthExponent(1), 15, 45, lossExponent);
             sensor2 = rfSensor;
-            sensor2 = sensor2.initialize(P_TX, BW, f_c, G_RX_dBi, 10, 150);
+            sensor2 = sensor2.initialize(P_TX, BW, f_c, G_RX_dBi, beamwidthExponent(2), 10, 150, lossExponent);
             sensor3 = rfSensor;
-            sensor3 = sensor3.initialize(P_TX, BW, f_c, G_RX_dBi, 20, 200);
+            sensor3 = sensor3.initialize(P_TX, BW, f_c, G_RX_dBi, beamwidthExponent(3), 20, 200, lossExponent);
 
             pos1 = [0,  0,  altitude];
             pos2 = [6, -4,  altitude - 1];