| 摘要: |
| 针对无线超宽带传感网中OFDM信号的接收,研究了基于多窄带接收设备的阵列化处理方法,以带宽拼接的方式实现超宽带(ultra-widdband,简称UWB)OFDM信号的接收与处理.首先,将超宽带OFDM信号的频带切分成许多子带,其中每两个相邻子带之间至少有一个子载波重叠.这样,超宽带OFDM信号被分解成多个子信号.与子带相等数目的窄带接收设备组成接收阵列,这些窄带设备分别工作在不同的子带上,以分布式协作的方式对相应子信号进行采样.然后,以相邻设备对重叠子载波的采样为依据,利用峰值对齐匹配法(peak value alignment retrieval, 简称PVAR)对相邻窄带接收设备采样数据进行时间对齐.再根据对齐的结果进行带宽拼接式数据融合,得到超宽带OFDM信号的离散信号.由于窄带接收设备的实现只需要低速ADC,因此有效解决了传统超宽带OFDM接收机中高速ADC的挑战.通过仿真考察了这种方法的有效性、同步误差的容错性、设备数量的扩展性以及不同信噪比影响下的性能. |
| 关键词: 超宽带 无线传感网 OFDM 接收阵列 时间对齐 带宽拼接 ADC |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金(61070203,61202484);国家教育部博士点基金(20124307120033) |
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| Array Receiving Scheme for Ultra-Wideband WSN OFDM Signals |
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DU Xiao-Li, LÜ Shao-He, WANG Xiao-Dong, ZHOU Xing-Ming
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Science and Technology on Parallel and Distributed Processing Laboratory National University of Defense Technology, Changsha, 410073, China
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| Abstract: |
| This paper proposes an array receiving scheme for ultra-wideband (UWB) OFDM signals in WSN networks. The major feature of the proposed scheme is recovering the UWB OFDM signal by frequency stitching. Firstly, the UWB OFDM signal is divided into multiple sub-bands. Every two adjacent sub-bands share at least one overlapped subcarrier(s), which is used for time alignment later. A sub-signal of the UWB OFDM signal is received on each sub-band by a narrow-band receiver. The received data sets of narrow-band receivers are time aligned by performing peak value alignment retrieval (PVAR) on the shared subcarriers. Then the UWB OFDM signal is recovered by fusing the received data sets according to the result of PVAR. As the implementation of narrow-band receivers only needs low-speed ADCs, the challenge of high-speed ADC in traditional UWB OFDM receiver is addressed. Extensive simulations are performed to demonstrate the validity of the proposed scheme and further look into three performance metrics: (1) synchronization error-tolerance, (2) extensibility, (3) performance under different SNR values. |
| Key words: Ultra-Wideband wireless sensor network OFDM receiving array time alignment frequency stitching ADC |
