iq capture feature

user_space/side_ch_ctl_src/iq_capture.py

@@ -0,0 +1,122 @@
+#
+# openwifi side info receive and display program
+# Xianjun jiao. putaoshu@msn.com; xianjun.jiao@imec.be
+#
+import os
+import sys
+import socket
+import numpy as np
+import matplotlib.pyplot as plt
+
+def display_iq(iq_capture, agc_gain, rssi_half_db):
+   
+    fig_iq_capture = plt.figure(0)
+    fig_iq_capture.clf()
+    plt.xlabel("sample")
+    plt.ylabel("I/Q")
+    plt.title("I (blue) and Q (red) capture")
+    plt.plot(iq_capture.real, 'b')
+    plt.plot(iq_capture.imag, 'r')
+    plt.ylim(-32767, 32767)
+    fig_iq_capture.show()
+    plt.pause(0.0001)
+
+    agc_gain_lock = np.copy(agc_gain)
+    agc_gain_lock[agc_gain>127] = 80 # agc lock
+    agc_gain_lock[agc_gain<=127] = 0 # agc not lock
+
+    agc_gain_value = np.copy(agc_gain)
+    agc_gain_value[agc_gain>127] = agc_gain[agc_gain>127] - 128
+
+    fig_agc_gain = plt.figure(1)
+    fig_agc_gain.clf()
+    plt.xlabel("sample")
+    plt.ylabel("gain/lock")
+    plt.title("AGC gain (blue) and lock status (red)")
+    plt.plot(agc_gain_value, 'b')
+    plt.plot(agc_gain_lock, 'r')
+    plt.ylim(0, 82)
+    fig_agc_gain.show()
+    plt.pause(0.0001)
+
+    fig_rssi_half_db = plt.figure(2)
+    fig_rssi_half_db.clf()
+    plt.xlabel("sample")
+    plt.ylabel("dB")
+    plt.title("RSSI half dB (uncalibrated)")
+    plt.plot(rssi_half_db)
+    plt.ylim(100, 270)
+    fig_rssi_half_db.show()
+    plt.pause(0.0001)
+
+def parse_iq(iq, iq_len):
+    # print(len(iq), iq_len)
+    num_dma_symbol_per_trans = 1 + iq_len
+    num_int16_per_trans = num_dma_symbol_per_trans*4 # 64bit per dma symbol
+    num_trans = round(len(iq)/num_int16_per_trans)
+    # print(len(iq), iq.dtype, num_trans)
+    iq = iq.reshape([num_trans, num_int16_per_trans])
+    
+    timestamp = iq[:,0] + pow(2,16)*iq[:,1] + pow(2,32)*iq[:,2] + pow(2,48)*iq[:,3]
+    iq_capture = iq[:,4::4] + iq[:,5::4]*1j
+    agc_gain = iq[:,6::4]
+    rssi_half_db = iq[:,7::4]
+    # print(num_trans, iq_len, iq_capture.shape, agc_gain.shape, rssi_half_db.shape)
+
+    iq_capture = iq_capture.reshape([num_trans*iq_len,])
+    agc_gain = agc_gain.reshape([num_trans*iq_len,])
+    rssi_half_db = rssi_half_db.reshape([num_trans*iq_len,])
+
+    return timestamp, iq_capture, agc_gain, rssi_half_db
+
+UDP_IP = "192.168.10.1" #Local IP to listen
+UDP_PORT = 4000         #Local port to listen
+
+sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) # UDP
+sock.bind((UDP_IP, UDP_PORT))
+
+# align with side_ch_control.v and all related user space, remote files
+MAX_NUM_DMA_SYMBOL = 8192
+
+if len(sys.argv)<2:
+    print("Assume iq_len = 8187! (Max UDP 65507 bytes; (65507/8)-1 = 8187)")
+    iq_len = 8187
+else:
+    iq_len = int(sys.argv[1])
+    print(iq_len)
+    # print(type(num_eq))
+
+if iq_len>8187:
+    iq_len = 8187
+    print('Limit iq_len to 8187! (Max UDP 65507 bytes; (65507/8)-1 = 8187)')
+
+num_dma_symbol_per_trans = 1 + iq_len
+num_byte_per_trans = 8*num_dma_symbol_per_trans
+
+if os.path.exists("iq.txt"):
+    os.remove("iq.txt")
+iq_fd=open('iq.txt','a')
+
+while True:
+    try:
+        data, addr = sock.recvfrom(MAX_NUM_DMA_SYMBOL*8) # buffer size
+        # print(addr)
+        test_residual = len(data)%num_byte_per_trans
+        # print(len(data)/8, num_dma_symbol_per_trans, test_residual)
+        if (test_residual != 0):
+            print("Abnormal length")
+
+        iq = np.frombuffer(data, dtype='int16')
+        np.savetxt(iq_fd, iq)
+
+        timestamp, iq_capture, agc_gain, rssi_half_db = parse_iq(iq, iq_len)
+        print(timestamp)
+        display_iq(iq_capture, agc_gain, rssi_half_db)
+
+    except KeyboardInterrupt:
+        print('User quit')
+        break
+
+print('close()')
+side_info_fd.close()
+sock.close()