Interference-Free OFDM: Rethinking OFDM for Interference Networks with Inter-Symbol Interference
Interference-Free OFDM: Rethinking OFDM for Interference Networks with Inter-Symbol Interference
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无干扰 OFDM：重新思考针对具有符号间干扰的干扰网络的 OFDM
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发表时间：
2016
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影响因子：
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通讯作者：
N. Lee
中科院分区：
文献类型：
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作者：
N. Lee
本文考虑具有符号间干扰（ISI）的$K$用户单输入单输出干扰信道，其中信道系数被假设为具有有限长度脉冲响应的线性时不变性。本文的主要发现是，在发射机 (CSIT) 处没有信道状态信息的情况下，只要所需链路比干扰链路具有更长的脉冲响应，总谱效率就可以与 $K$ 成线性比例。这种线性增益是通过一种新颖的多载波通信方案实现的，我们称之为\textit{无干扰正交频分复用（IF-OFDM）}。此外，当发射机能够仅从其配对接收机学习CSIT时，通过将IF-OFDM和基于奇异值分解的矢量编码与注水功率分配相结合的两级传输方法可以实现更高的和谱效率。导出结果的主要含义是，每个链路的子载波之间的单独编码足以线性增加具有 ISI 的干扰信道中的和谱效率 $K$。模拟结果支持了这一说法。
This paper considers a $K$-user single-input-single-output interference channel with inter-symbol interference (ISI), in which the channel coefficients are assumed to be linear time-invariant with finite-length impulse response. The primary finding of this paper is that, with no channel state information at a transmitter (CSIT), the sum-spectral efficiency can be made to scale linearly with $K$, provided that the desired links have longer impulse response than do the interfering links. This linear gain is achieved by a novel multi-carrier communication scheme which we call \textit{interference-free orthogonal frequency division multiplexing (IF-OFDM)}. Furthermore, when a transmitter is able to learn CSIT from its paired receiver only, a higher sum-spectral efficiency can be achieved by a two-stage transmission method that concatenates IF-OFDM and vector coding based on singular value decomposition with water-filling power allocation. A major implication of the derived results is that separate encoding across subcarriers per link is sufficient to linearly increase the sum-spectral efficiency with $K$ in the interference channel with ISI. Simulation results support this claim.