Add more unit tests to awgn_capacity()

tests/link_budgets/test_awgn_capacity.py

@@ -10,3 +10,27 @@ def test_absolute_limit():
     ebn0 = esn0 - 10 * np.log10(C)
     ebn0_limit = 10 * np.log10(np.log(2))  # ~ -1.59 dB
     assert ebn0 == pytest.approx(ebn0_limit)
+
+
+def test_vector():
+    """
+    These numbers were verified visually from published papers.
+    """
+    snr = np.linspace(-30, 20, 11)
+    C = sdr.awgn_capacity(snr)
+    C_truth = np.array(
+        [
+            1.44197417e-03,
+            4.55500399e-03,
+            1.43552930e-02,
+            4.49155310e-02,
+            1.37503524e-01,
+            3.96409161e-01,
+            1.00000000e00,
+            2.05737321e00,
+            3.45943162e00,
+            5.02780767e00,
+            6.65821148e00,
+        ]
+    )
+    assert np.allclose(C, C_truth)