Analysis of the Frequency Offset Effect on Random Access Signals

作者：Hua Min^*; Wang Mao; Yang Wenjie; You Xiaohu; Shu Feng; Wang Jianxin; Sheng Weixing; Chen Qian

来源：IEEE Transactions on Communications, 2013, 61(11): 4728-4740.

DOI：10.1109/TCOMM.2013.091813.130045

• Random access signal
• Zadoff-Chu sequence
• frequency offset
• critical frequency offset
• Zadoff-Chu sequence set spectrum

Zadoff-Chu (ZC) sequences have been used as random access sequences in modern wireless communication systems, replacing the conventional pseudo-random-noise (PN) sequences due to their superior autocorrelation properties. An analytical framework quantifying the ZC sequence's performance and its fundamental limitation as a random access sequence in the presence of frequency offset between the transmitter and the receiver is introduced. We show that a ZC sequence's perfect autocorrelation properties can be severely impaired by the frequency offset thereby limiting the overall performance of the random access signals formed from these sequences. First, we derive the autocorrelation function of these random access sequences as a function of the frequency offset. Next, we introduce the concept of critical frequency offsets and the spectrum associated with a ZC sequence set to characterize the frequency offset properties of the random access signals. Finally, we demonstrate that the frequency offset immunity of a ZC sequence set can be controlled by shaping the spectrum of the ZC sequence set.

• 出版日期2013-11
• 单位南京大学