In this paper, we present a frame structure that can be viewed as a preamble for the detection and synchronization process (leading to low cost receiver) and as an encoded codeword carrying the transmitted message (leading to reliable transmission). This duality facilitates an ALOHA protocol avoiding preamble overhead. The frame structure, named Quasi-Cyclic Short Packet (QCSP), is based on the association of a Cyclic Code Shift Keying (CCSK) modulation and a non-binary error control code. The detection/correction algorithm of the QCSP system is presented, its performance is theoretically derived and discussed for different parameters. A QCSP frame can be transmitted and received correctly with an error probability of 10−4\mathbf {10^{-4}} , distanced by 1.2 dB from Polyanskiy’s bound (an estimated Shannon’s limit for small packet size) at −11 dB of SNR for a payload of 360 bits. Compared to a classical preamble-based frame using a modern binary error control code, the size of a QCSP frame is reduced by 23%. Moreover, detecting a QCSP frame requires a lower complexity than detecting a longer classical preamble.

中文翻译：

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通过将 CCSK 调制与 NB 代码相关联，以极低 SNR 进行短帧传输


在本文中，我们提出了一种帧结构，它可以被视为检测和同步过程的前导码（导致低成本接收器）和承载传输消息的编码码字（导致可靠传输）。这种二元性有利于 ALOHA 协议避免前导码开销。该帧结构称为准循环短数据包 (QCSP)，基于循环码移键控 (CCSK) 调制和非二进制错误控制码的关联。提出了QCSP系统的检测/校正算法，从理论上推导了其性能并针对不同参数进行了讨论。 QCSP 帧可以正确发送和接收，错误概率为 10−4\mathbf {10^{-4}} ，与 Polyanskiy 边界（小数据包大小的估计香农极限）相差 1.2 dB，-11 dB 为360 位有效负载的 SNR。与使用现代二进制错误控制码的经典前导码帧相比，QCSP 帧的大小减少了 23%。此外，检测 QCSP 帧比检测较长的经典前导码所需的复杂度更低。