STTGR: A bandwidth extension receiving scheme for large-bandwidth OFDM signals

Large bandwidth is indispensable for future high-speed wireless transmission. However, implementation of traditional receiver demands ultra-high-speed ADC to receive large-bandwidth signals, which is challenging for current manufacturing. Motivated to defeat this challenge, we propose STTGR, which is literally extracted from stitching-together receiving. STTGR is a bandwidth extension receiving scheme by means of frequency stitching-together. Considering the immense potential of OFDM in wireless communication, STTGR is specialized for OFDM signals. Firstly, STTGR clips the signal frequency band into multiple sub-bands, and the OFDM signal is analyzed into multiple sub-signals accordingly. An array of narrow-band receivers is utilized to obtain the digital samples of the sub-signals. We employ peak value alignment retrieval (PVAR) to time align the digital samples of the sub-signals. Then the digital samples of sub-signals are combined into a union in a stitching-together way and we get the digital version of the OFDM signal. As the implementation of narrow-band receivers only needs low-speed ADC, the traditional challenge of ultra-high-speed ADC is defeated. Subsequent steps in OFDM receiver are performed normally after STTGR, such as FFT, demapper and so on. The most important superiority of STTGR is the ability to adapt its receiving bandwidth to the signal bandwidth by adjusting the number of narrow-band receivers. There is no upper limit for the receiving bandwidth of STTGR. We perform extensive simulations to demonstrate the validity of STTGR, and further look into the performance of STTGR from three aspects, synchronization error-tolerance, extensibility and performance under different SNR values.