Espressif Systems (Shanghai) Co., Ltd.

Espressif Systems (Shanghai) Pte Ltd

Expressif Systems (Shanghai) Pte. Ltd.

Rui Zhan

Hao Lin

Swee Ann Teo

Lu Kong

Jiangjian Jiang

Shi Chen

Liwei Jiang

A signal detection method for a MIMO-OFDM wireless communication system includes obtaining a channel matrix of each subcarrier through channel estimation for each MIMO-OFDM data packet in a plurality of MIMO-OFDM data packets; receiving a reception vector of each subcarrier; performing channel matrix preprocessing for the channel matrix of each subcarrier to generate a global dynamic K-value table, in which the global dynamic K-value table includes a global dynamic K-value corresponding to each search layer of each subcarrier; performing MIMO detection for each OFDM symbol in the MIMO-OFDM data packet, in which the MIMO detection includes performing the following steps for each subcarrier of a current OFDM symbol: reading channel matrix preprocessing results and reception vector of the current subcarrier; transforming the reception vector of the current subcarrier into an LR search domain; and performing K-best search for the current subcarrier to obtain an LR domain candidate transmission vector of the current subcarrier, in which a K-value applied to each search layer of the current subcarrier during the K-best search is a global dynamic K-value in the global dynamic K-value table corresponding to the search layer.

MIMO-OFDM wireless signal detection method and system capable of channel matrix pre-processing before detection

The present disclosure discloses an adaptive MIMO detection method and system. The method includes the following steps: a) determining whether a Signal to Noise Ratio of a data packet is greater than a set threshold for Signal to Noise Ratio, and if yes, performing ZF preprocessing on the channel matrix, and if not, performing MMSE preprocessing on the channel matrix; b) performing sorted QR decomposition on the channel matrix processed in step a) to obtain a plurality of decomposition matrices; c) determining whether a condition number of the channel matrix of the data packet is greater than a set threshold for condition number of the channel, and if yes, Lattice Reduction is performed on the decomposition matrices obtained in step b); d) determining whether an estimated value of an interference term of the channel matrix is greater than a threshold for the estimated value of the interference term of the channel matrix, and if yes, SIC detection mode is selected for MIMO detection on the data packets, and if not, K-best detection mode is selected for MIMO detection on the data packets; and e) according to processing results from steps a) to d), performing MIMO detection on the data packet.

Self-adaptive MIMO detection method and system

The present invention discloses a method for processing a preamble sequence and header for a data packet, comprising the following steps of: using a bit sequence of a fixed pattern to replace a scrambled pseudo-random bit sequence in a SYNC field in the preamble sequence, and spreading the SYNC field by a Barker code; extending a length of a spreading code and spreading an SFD field in the preamble sequence by the extended spreading code; and extending a length of a spreading code and spreading a header field by the extended spreading code. The present invention may significantly improve the performance of reception and detection for the preamble sequence (the SYNC field and the SFD field) and the PLCP header field, better overcome long-distance channel conditions, enhance the signal stability of transmission; and meanwhile the present invention is easy to implement and only requires little modifications to the circuit of a conventional Wi-Fi device.

Data-packet preamble sequence and packet header, and processing method and data frame thereof

A signal detection method for a MIMO-OFDM wireless communication system includes obtaining a channel matrix of each subcarrier for each MIMO-OFDM data packet; receiving a reception vector of each subcarrier; performing MIMO detection for a first OFDM symbol and channel matrix preprocessing to generate a global dynamic K-value table; performing MIMO detection for each subsequent OFDM symbol, the MIMO detection includes: performing the following steps for each subcarrier of a current OFDM symbol: transforming the reception vector of the current subcarrier into a LR search domain; and obtaining a LR domain candidate transmission vector of the current subcarrier, a K-value applied to each search layer of the current subcarrier during the K-best search is a global dynamic K-value in the global dynamic K-value table corresponding to the search layer.

MIMO-OFDM wireless signal detection method and system capable of channel matrix pre-processing during detection

The present invention relates to a positioning method and system based on a Wi-Fi IoT device network, wherein positioning monitoring nodes in a subnet respectively receives, within an information receiving and transmitting range thereof, a data packet sent by a same positioning target device, records corresponding data packet receipt clock information, and provides the data packet receipt clock information and identification information of the positioning target device to the subnet master node; the subnet master node utilizes signal arrival time differences between a plurality of positioning monitoring nodes receiving the data packet from the same positioning target device, and mutual physical distances between the positioning monitoring nodes, to compute the distance differences of the positioning target device with respect to the plurality of positioning monitoring nodes, and determine a position of the positioning target device in a physical coverage range of the subnet. The present invention may achieve the real-time positioning and monitoring of a large number of targets in a large physical range.

Positioning method and system based on Wi-Fi internet of things device network

A method for implementing a low power consumption IoT network based on a Wi-Fi proxy device. The network is used for low power consumption data exchange between a Wi-Fi IoT device having a long data period in a Wi-Fi IoT network and an internet server, via a Wi-Fi proxy IoT device and a Wi-Fi access point. A low power consumption Wi-Fi MAC layer link is provided between the proxy device and at least one Wi-Fi IoT device. The Wi-Fi IoT device only establishes a low power consumption Wi-Fi MAC layer link with the proxy device. The proxy device connects to the internet server via a Wi-Fi access point, and acts as a data receiving end to buffer data, from the internet server, that is sent to the Wi-Fi IoT device via the Wi-Fi MAC layer link.

Implementation method of low power consumption internet of things based on proxy apparatus

The present invention relates to an IoT control switch and method based on fingerprint identification permission control, comprising performing user identity and permission verification through fingerprint identification, implementing a MAC layer connectionless communication mechanism between a wire-free fingerprint Wi-Fi IoT switch and a standard Wi-Fi IoT device, and carrying control information for controlling the Wi-Fi IoT device by a privately defined control information element in a unicast packet or broadcast packet without requiring a MAC layer connection; the invention requires little modification, is cost effective to implement, and the data type, manner of acknowledgement, manner of encryption, and different fingerprint security control modes may be freely combined with each other, thereby providing wide applicability. The wire-free fingerprint Wi-Fi IoT switch may complete the translation of control information to the standard Wi-Fi IoT device by sending least number of packets, so as to realize low power consumption control. The wire-free fingerprint Wi-Fi IoT switch may also connect to an internet server via a Wi-Fi access point to perform update and upgrade of firmware, fingerprint feature information list, etc.

Fingerprint identification authority control-based internet of things control switch and method

A sonar-integrated IoT device, the IoT device including one or more sonar sensor modules (), corresponding to information acquisition in different spatial directions; the IoT device is in communication connection with an external signal processing unit through a wireless network, and sends unprocessed or preliminarily processed spatial information to the signal processing unit. The advantages of the invention include: simple and flexible arrangement of sonar sensor module () nodes, which are integrated with wireless IoT devices such that spatial information may be acquired locally; and at the same time, ease of implementation of large interval arrangement and large quantity arrangement of sonar sensor modules (), covering a variety of spatial locations, thereby providing wide coverage of spatial detection range, and acquisition of abundant signal samples, such that better spatial information extraction algorithms may be implemented in the signal processing unit.

Sonar-integrated internet of things device and applicable spatial environment detection system thereof

The present invention discloses a unidirectional bit error correction method for a OTP ROM, comprising: applying error correction encoding to bit information and writing the bit information to the OTP ROM; during power-up initialization, converting hard bit information read out from the OTP ROM to soft bit information; during the power-up initialization, performing error correction decoding through a soft bit decoder. The advantages of the present invention include: utilizing otherwise temporarily idle decoding modules in the chip, without requiring additional hardware resource, while providing stronger error correction capability to the OTP ROM, improving the stability of chip applications, prolonging chip service life, and significantly reducing rejection rate in chip production.

Unidirectional bit error correcting method for OTP ROM

A communication method for Wi-Fi Internet of Things equipment, which is used for Wi-Fi Internet of Things main control equipment to send control information to Wi-Fi Internet of Things controlled equipment, in which Wi-Fi Internet of main control equipment and Wi-Fi Internet of Things controlled equipment complete pairing, and acquire a MAC address and a communication key of each other; the Wi-Fi Internet of main control equipment sends control information to the Wi-Fi Internet of Things controlled equipment by loading a private information structure in a Wi-Fi unicast packet or multicast packet; and the Wi-Fi Internet of Things controlled equipment sends confirmation information to the Wi-Fi Internet of Things main control equipment after receiving the control information.

Communication method for Wi-Fi internet of things equipment and Wi-Fi internet of things system

Disclosed is a distributed microphone array. The array comprises: a plurality of distributed microphone array nodes, wherein each microphone array node is provided with one or a plurality of microphone audio acquisition modules; and the microphone array node is connected to an external signal processing unit by means of wireless network communication, and uploads an unprocessed audio signal or an audio signal which has undergone simple signal processing on the array node to the signal processing unit. In the present invention, all the wireless microphone array nodes distributed in a wireless network form a large microphone array. In a wireless microphone array, microphone signal acquisition and transmission are based on a wireless type, and the distribution of microphones is no longer limited by a physical dimension or a cabling connection, so that the distribution of a significant amount of microphones can be achieved, and the distance between the microphones and the coverage area of the microphone array can be greatly increased.

Distributed microphone array and sound source positioning system applicable thereto

A heterogeneous method of a Wi-Fi Internet of things (IoT) that includes arranging at least one Wi-Fi IoT bridging device in a Wi-Fi IoT, the Wi-Fi IoT bridging device using a time division technique and communicating with at least one distant IoT device in a reduced data rate mode; and a heterogeneous IoT framework that includes a wireless router connecting to an IoT and supporting a standard Wi-Fi link, bridging device connecting to the wireless router via the standard Wi-Fi link, and a Wi-Fi device in a reduced data rate mode connecting to the bridging device via the reduced data rate mode, thereby realizing bridging and swapping of data in a heterogeneous Wi-Fi IoT structure consisting of Wi-Fi IoT subnets having different baseband rates.

Heterogeneous method and framework of Wi-Fi Internet of things

A compatible configuration method for an IoT device, wherein, by adding an energy detection device and a length verification device having a timer to a digital baseband demodulation portion of a Wi-Fi IoT device, when the Wi-Fi IoT device detects an HT-SIG field or VHT-SIG-B field in a header of a configuration information packet from a master device, starting the timer and the energy detection device, so as to judge whether receipt is successful based on whether a recorded time length when channel energy reaches a lower limit conforms to length information in the HT-SIG field or VHT-SIG-B field in the header of a configuration information packet for a higher frequency band mode; and after successful receipt, obtaining transmitted configuration access information sections by computing length differences between received configuration information packets, and then combining the received information sections to obtain configuration access information.

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Shanghai, China

Rui Zhan