###### Abstract  
Millions of smart home devices equipped with wireless sensors have gradually entered people's homes and improved the quality of life. Wireless communication with sensors is crucial for remote automatic control of smart devices. Packet detection is one of the key technologies in wireless communication systems and faces the challenges of detection accuracy and power consumption. In households, WiFi devices are widely deployed. Therefore, we focus on IEEE 802.11 OFDM packet detection algorithms for household wireless sensor communication. We first introduce four packet detection algorithms and verify their feasibility by simulation experiments. Then, we identify two important factors that affect detection accuracy and provide suggestions for algorithm improvement. Further, we compare and discuss the performance of the four algorithms from three dimensions in detail. The results show that each algorithm has its own advantages, and the auto-correlation algorithm has the best overall performance. Finally, we point out the open challenges and future research directions in this field. critical step for wireless data processing, as shown in Figure 1. The remaining operations occur only when a packet is detected. In households, the performance of packet detection greatly affects the communication quality between various smart home devices. At present, wireless communication systems are mainly divided into two categories, active transmission and passive transmission. The computational complexity afforded by the two systems is diverse due to different system power constraints. The active systems can perform complex operations but require more energy. To obtain enough energy, two main power supply methods, plug-in and battery-based, are used. The former is inconvenient in households and the latter is limited by short lifespan and poor sustainability, and requires regular battery replacement. In recent years, passive wireless communication systems [8; 9; 10] have become the focus of research. Such systems have an autonomous energy-harvesting module and can achieve near-zero power consumption. They remove the limitation of the battery and make the household wireless sensors able to be deployed once for long-term use, but they cannot perform complex computations due to power constraints. Both systems require packet detection, so when designing detection algorithms, there are two main issues that need to be considered. * Detection accuracy. The detection accuracy is reflected in two aspects. First, the packet detection algorithms should detect packets as correctly as possible, achieving a high detection rate. Second, the start position of the incoming data packet should be found as precisely as possible for better synchronization. * Computational complexity. To meet the requirements of low power consumption for passive wireless communication systems, the computational complexity of the packet detection algorithms applied to such systems must be low. Complex computation should be avoided. Wireless communication protocols include WiFi, Bluetooth, LoRa, ZigBee, RFID, etc. In households, the most commonly used protocol is WiFi, which has a high transmission rate, long communication distance, and good penetration. Among the protocol standards of WiFi, IEEE 802.11 is the most widely used in daily life. Orthogonal frequency division multiplexing (OFDM) has become the key transmission technique for high-speed mobile communication systems. Therefore, we focus on packet detection algorithms for 802.11 OFDM signals in this paper. Many packet detection algorithms have been applied to existing systems. However, the previous researchers either introduced the algorithms briefly, or just gave an improvement or application of an algorithm. No one, yet, has  
Figure 1: Packet detection is a key technology for smart household wireless communication systems. systematically analyzed and compared these algorithms. Packet detection is a key technical that needs to be broken through, but no major breakthrough has been achieved so far.