python
# 传输速率取决于带宽，发送者的功率，期望到达的距离
def get_rate(B, power, distance):
P_mw = math.pow(10, power / 10) # mW
N0_mw_MHz = math.pow(10, N0 / 10) # mW/MHz
path_loss = 10 * salpha * math.log(distance, 10) + C_path_loss # dB
channel_variance = math.pow(10, -0.1 * path_loss)
sigma = math.sqrt((2 / (4 - math.pi)) * math.sqrt(channel_variance))
h = sigma / (distance * distance)
c = B * 1000 * math.log(1 + (P_mw * h) / (B) * N0_mw_MHz), 2) # bit/ms
return c # bit/ms
