add option to generate board signal with no overlapping bands

Author: zhiim

doa_py/__init__.py

@@ -113,5 +113,5 @@
 file for details.
 """
 
-__version__ = "0.2.2"
+__version__ = "0.2.3"
 __author__ = "Qian Xu"

doa_py/algorithm/broadband.py

@@ -144,7 +144,6 @@ def cssm(
     if fre_ref is None:
         # Find the frequency point with the maximum power
         fre_ref = fre_bins[np.argmax(np.abs(signal_fre_bins).sum(axis=0))]
-        print(fre_ref)
 
     # Calculate the manifold matrix corresponding to the pre-estimated angles at
     # the reference frequency point
@@ -214,7 +213,6 @@ def tops(
 
     if fre_ref is None:
         fre_ref = fre_bins[np.argmax(np.abs(signal_fre_bins).sum(axis=(0, 2)))]
-        print(fre_ref)
 
     # index of reference frequency in FFT output
     ref_index = int(fre_ref / (fs / fre_bins.size))

doa_py/arrays.py

@@ -2,7 +2,7 @@
 
 import numpy as np
 
-from .signals import BroadSignal
+from .signals import BroadSignal, NarrowSignal, Signal
 
 C = 3e8  # wave speed
 
@@ -88,11 +88,13 @@ def steering_vector(self, fre, angle_incidence, unit="deg"):
 
     def received_signal(
         self,
-        signal,
+        signal: Signal,
         angle_incidence,
         snr=None,
         nsamples=100,
         amp=None,
+        min_length_ratio=0.1,
+        no_overlap=False,
         unit="deg",
     ):
         """Generate array received signal based on array signal model
@@ -110,6 +112,10 @@ def received_signal(
             snr: Signal-to-noise ratio. If set to None, no noise will be added
             nsamples (int): Number of snapshots, defaults to 100
             amp: The amplitude of each signal, 1d numpy array
+            min_length_ratio (float): Minimum length ratio of the frequency
+                range in (f_max - f_min)
+            no_overlap (bool): If True, generate signals with non-overlapping
+                subbands
             unit: The unit of the angle, `rad` represents radian,
                 `deg` represents degree. Defaults to 'deg'.
         """
@@ -118,16 +124,24 @@ def received_signal(
 
         if isinstance(signal, BroadSignal):
             received = self._gen_broadband(
-                signal, snr, nsamples, angle_incidence, amp
+                signal,
+                snr,
+                nsamples,
+                angle_incidence,
+                amp,
+                min_length_ratio,
+                no_overlap,
             )
-        else:
+        if isinstance(signal, NarrowSignal):
             received = self._gen_narrowband(
                 signal, snr, nsamples, angle_incidence, amp
             )
 
         return received
 
-    def _gen_narrowband(self, signal, snr, nsamples, angle_incidence, amp):
+    def _gen_narrowband(
+        self, signal: NarrowSignal, snr, nsamples, angle_incidence, amp
+    ):
         """Generate narrowband received signal
 
         `azimuth` and `elevation` are already in radians
@@ -150,7 +164,16 @@ def _gen_narrowband(self, signal, snr, nsamples, angle_incidence, amp):
 
         return received
 
-    def _gen_broadband(self, signal, snr, nsamples, angle_incidence, amp):
+    def _gen_broadband(
+        self,
+        signal: BroadSignal,
+        snr,
+        nsamples,
+        angle_incidence,
+        amp,
+        min_length_ratio=0.1,
+        no_overlap=False,
+    ):
         """Generate broadband received signal
 
         `azimuth` and `elevation` are already in radians
@@ -162,7 +185,13 @@ def _gen_broadband(self, signal, snr, nsamples, angle_incidence, amp):
 
         num_antennas = self._element_position.shape[0]
 
-        incidence_signal = signal.gen(n=num_signal, nsamples=nsamples, amp=amp)
+        incidence_signal = signal.gen(
+            n=num_signal,
+            nsamples=nsamples,
+            min_length_ratio=min_length_ratio,
+            no_overlap=no_overlap,
+            amp=amp,
+        )
 
         # generate array signal in frequency domain
         signal_fre_domain = np.fft.fft(incidence_signal, axis=1)

doa_py/signals.py

@@ -150,10 +150,28 @@ def fs(self):
         return self._fs
 
     @abstractmethod
-    def gen(self, n, nsamples, amp=None):
+    def gen(
+        self, n, nsamples, min_length_ratio=0.1, no_overlap=False, amp=None
+    ):
+        """Generate sampled signals
+
+        Args:
+            n (int): Number of signals
+            nsamples (int): Number of snapshots
+            min_length_ratio (float): Minimum length ratio of the frequency
+                range in (f_max - f_min)
+            no_overlap (bool): If True, generate signals with non-overlapping
+                subbands
+            amp (np.array): Amplitude of the signals (1D array of size n), used
+                to define different amplitudes for different signals.
+                By default it will generate equal amplitude signal.
+
+        Returns:
+            signal (np.array): Sampled signals
+        """
         raise NotImplementedError
 
-    def _gen_fre_ranges(self, n, min_length_ratio=0.3):
+    def _gen_fre_bands(self, n, min_length_ratio=0.1):
         """Generate frequency ranges for each boardband signal
 
         Args:
@@ -166,12 +184,41 @@ def _gen_fre_ranges(self, n, min_length_ratio=0.3):
                 (n, 2)
         """
         min_length = (self._f_max - self._f_min) * min_length_ratio
-        ranges = np.zeros((n, 2))
+        bands = np.zeros((n, 2))
         for i in range(n):
             length = self._rng.uniform(min_length, self._f_max - self._f_min)
             start = self._rng.uniform(self._f_min, self._f_max - length)
-            ranges[i] = [start, start + length]
-        return ranges
+            bands[i] = [start, start + length]
+        return bands
+
+    def _generate_non_overlapping_bands(self, n, min_length_ratio=0.1):
+        """Generate n non-overlapping frequency bands within a specified range.
+
+        Args:
+            n (int): Number of non-overlapping bands to generate.
+            min_length_ratio (float): Minimum length of each band as a ratio of
+               the maximum possible length.
+
+        Returns:
+            np.ndarray: An array of shape (n, 2) where each row represents a
+               frequency band [start, end].
+        """
+        max_length = (self._f_max - self._f_min) // n
+        min_length = max_length * min_length_ratio
+
+        bands = np.zeros((n, 2))
+
+        for i in range(n):
+            length = self._rng.uniform(min_length, max_length)
+            start = self._rng.uniform(
+                self._f_min + i * max_length,
+                self._f_min + (i + 1) * max_length - length,
+            )
+            new_band = [start, start + length]
+
+            bands[i] = new_band
+
+        return bands
 
 
 class ChirpSignal(BroadSignal):
@@ -187,9 +234,15 @@ def __init__(self, f_min, f_max, fs, rng=None):
         """
         super().__init__(f_min, f_max, fs, rng=rng)
 
-    def gen(self, n, nsamples, amp=None):
+    def gen(
+        self, n, nsamples, min_length_ratio=0.1, no_overlap=False, amp=None
+    ):
         amp = self._get_amp(amp, n)
-        fre_ranges = self._gen_fre_ranges(n)
+        if no_overlap:
+            fre_ranges = self._generate_non_overlapping_bands(
+                n, min_length_ratio
+            )
+        fre_ranges = self._gen_fre_bands(n, min_length_ratio)
 
         t = np.arange(nsamples) * 1 / self._fs
         f0 = fre_ranges[:, 0]
@@ -222,9 +275,16 @@ def __init__(self, f_min, f_max, fs, ncarriers=100, rng=None):
         super().__init__(f_min, f_max, fs, rng=rng)
         self._ncarriers = ncarriers
 
-    def gen(self, n, nsamples, amp=None):
+    def gen(
+        self, n, nsamples, min_length_ratio=0.1, no_overlap=False, amp=None
+    ):
         amp = self._get_amp(amp, n)
-        fre_ranges = self._gen_fre_ranges(n)
+        if no_overlap:
+            fre_ranges = self._generate_non_overlapping_bands(
+                n, min_length_ratio
+            )
+        else:
+            fre_ranges = self._gen_fre_bands(n, min_length_ratio)
 
         # generate random carrier frequencies
         fres = self._rng.uniform(

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "doa_py"
-version = "0.2.2"
+version = "0.2.3"
 description = "DOA estimation algorithms implemented in Python"
 readme = "README.md"
 license = { text = "MIT" }