用300行左右Python进行OQAM_OFDM通感一体化波形设计

在300行左右的Python代码中实现OQAM (Offset Quadrature Amplitude Modulation) 和 OFDM (Orthogonal Frequency Division Multiplexing) 的一体化波形设计是一个相当复杂的任务，因为这涉及到了数字信号处理的一些核心概念和算法。以下是一个简化版的框架，实际完整实现可能会超过300行：

import numpy as np
import scipy.signal as sig
from matplotlib import pyplot as plt

# 定义基本参数
NFFT = 1024  # Fast Fourier Transform size
symbol_rate = 1e6  # Symbol rate in Hz
subcarrier_num = 512  # Number of subcarriers
guard_interval = 0.1  # Guard interval ratio
oqam_order = 2  # Order of OQAM modulation

# 创建时间轴
t = np.arange(0, NFFT/symbol_rate, 1/symbol_rate)

# 创建载波频率列表
carrier_frequencies = np.linspace(0, symbol_rate / 2, num=subcarrier_num)

# OFDM符号生成
def generate_ofdm_symbols(data):
    # 循环移位并拼接 OQAM 模拟数据
    symbols = []
    for i in range(oqam_order**2):  # OQAM阶数的平方
        shifted_data = np.roll(data, i * oqam_order)
        symbols.extend(shifted_data)
    return symbols

# OQAM调制
def qammodulate(data, order):
    constellation = np.zeros(order**2, dtype=complex)
    for idx, val in enumerate(np.array(range(order)) + 1j*np.array(range(order))):
        constellation[idx] = val
    return constellation[data]

# OQAM OFDM信号构建
def create_oqam_ofdm_signal(data, t, carrier_frequencies, guard_interval):
    ofdm_symbols = generate_ofdm_symbols(data)
    cyclic_prefix_len = int(guard_interval * NFFT)
    ofdm_signal = []

    for sym in ofdm_symbols:
        modulated_sym = qammodulate(sym, oqam_order)
        freq_domain = np.fft.ifftshift(np.fft.fft(modulated_sym, NFFT))
        time_domain = np.real(np.fft.ifft(freq_domain))

        # 添加循环前缀
        cp_time_domain = np.concatenate((time_domain[-cyclic_prefix_len:], time_domain[:len(time_domain)-cyclic_prefix_len]))
        ofdm_signal.append(cp_time_domain)

    return np.array(ofdm_signal), t

# 示例数据
data = np.random.randint(0, oqam_order**2, len(t))

# 生成OQAM OFDM信号
ofdm_signal, signal_t = create_oqam_ofdm_signal(data, t, carrier_frequencies, guard_interval)

# 可视化波形
plt.figure(figsize=(8, 4))
plt.plot(signal_t, ofdm_signal[0])
plt.title("OQAM-OFDM Signal")
plt.xlabel("Time (s)")
plt.ylabel("Amplitude")
plt.show()