Reference signals overhead reduction has recently evolved as an effective solution for improving the system spectral efficiency. This paper introduces a new downlink data structure that is free from demodulation reference signals (DM-RS), and hence does not require any channel estimation at the receiver. The new proposed data transmission structure involves a simple repetition step of part of the user data across the different sub-bands. Exploiting the repetition structure at the user side, it is shown that reliable recovery is possible via canonical correlation analysis. This paper also proposes two effective mechanisms for boosting the CCA performance in OFDM systems; one for repetition pattern selection and another to deal with the severe frequency selectivity issues. The proposed approach exhibits favorable complexity-performance tradeoff, rendering it appealing for practical implementation. Numerical results, using a 3GPP link-level testbench, demonstrate the superiority of the proposed approach relative to the state-of-the-art methods.

翻译：参考信号开销减少近期已成为提升系统频谱效率的有效方案。本文提出一种无需解调参考信号(DM-RS)的新型下行数据帧结构,从而在接收端完全避免信道估计。所提出的数据传输结构通过在不同子带上对部分用户数据进行简单重复处理。利用用户侧的重复结构特性,证明基于典型相关分析可实现可靠数据恢复。本文还提出两种在OFDM系统中提升CCA性能的有效机制:一种用于重复模式选择,另一种用于处理严重的频率选择性衰落问题。所提方法在复杂度和性能之间取得良好平衡,使其具有实际应用价值。基于3GPP链路级测试平台的数值结果表明,相较于现有方法,所提方案具有显著优越性。