A sub-sampling method developed for wired or wireless Orthogonal Frequency Division Multiplexing (OFDM) systems is presented. The proposed technique can be activated during the exchange of sparse data. The sub-sampling method is implemented with low cost and complexity hardware since it requires the customization of a few specific OFDM stages like channel interleaving, sampling control, etc, and does not require any iterative optimization procedure. Employing special Inverse-Fast Fourier Transform (I-FFT) input structures, the recovery of the original data from fewer samples than those required by the receiver FFT is possible without any other cost for general OFDM applications. A special detector initiates the sub-sampling mode when sparse information is exchanged like sensor data or uncompressed real-time video with stationary views like night surveillance cameras. Up to ¾ of the time, the system can operate in sub-sampling mode reducing the power consumed by the Analogue/Digital Converter (ADC), the FFT and the IFFT. Memory needed for sample storage, intermediate results and FFT/IFFT coefficients can be released in real time if the proposed architecture is adopted. A Bit Error Rate (BER) below 10⁻³ or full information recovery is achieved in most of the cases. An image reconstruction example is also tested in a wireless environment with Normalised Mean Square Error (NMSE) ranging from 10⁻⁵ to less than 0.1.

提出了一种为有线或无线正交频分复用 (OFDM) 系统开发的子采样方法。可以在交换稀疏数据期间激活所提出的技术。子采样方法是用低成本和复杂的硬件实现的，因为它需要定制一些特定的 OFDM 阶段，如信道交织、采样控制等，并且不需要任何迭代优化过程。采用特殊的快速傅立叶逆变换 (I-FFT) 输入结构，可以从比接收器 FFT 所需的样本更少的样本中恢复原始数据，而无需任何其他成本，用于一般 OFDM 应用。当稀疏信息（如传感器数据或未压缩的实时视频与夜间监控摄像机等静止视图）交换时，一个特殊的检测器会启动子采样模式。多达 3/4 的时间，系统可以在子采样模式下运行，从而降低模数转换器 (ADC)、FFT 和 IFFT 的功耗。如果采用所提出的架构，则可以实时释放样本存储、中间结果和 FFT/IFFT 系数所需的内存。误码率 (BER) 低于 10 ^-3或在大多数情况下实现完全信息恢复。图像重建示例也在无线环境中进行了测试，归一化均方误差 (NMSE) 范围从 10 ^-5到小于 0.1。