Abstract: The present invention relates to a layered semi-parallel LDPC decoder system having a single permutation network, and belongs to the field of decoder hardware design. The system comprises a layered decoding architecture of the single permutation network, a layered semi-parallel decoding architecture of the single permutation network, a pipeline design for layered semi-parallel decoding and a hardware framework of a layered semi-parallel LDPC decoder. The present invention removes a permutation network module between a check node and a variable node by modifying the cyclic shift value of each information block transferred from the variable node to the check node, i.e., the cyclic shift operation of the decoder can be completed through the single permutation network so as to reduce hardware resources of the decoder. A semi-parallel decoding structure is adopted, and meanwhile, a pipeline is added between half layers.

Abstract: The present invention relates to a consensus-based clock synchronization skew estimation method based on sequential least squares, and belongs to the technical field of wireless sensor networks. The method is to establish a relationship model of clock information and time delay between nodes with respect to a bounded random communication time delay scenario subject to arbitrary distribution, fully consider all clock information received by a node from a neighbor, build a clock parameter estimation model and a cost function based on a least squares principle, iteratively estimate relative clock skew by a sequential least squares method, and update logical clock parameters of nodes by a consensus-based clock synchronization method, so as to achieve global clock consistency of all nodes in a network in a completely distributed way.

Abstract: The present invention relates to an improved KNN-based 6LoWPAN network intrusion detection method. The present invention selects quantifiable security features which can reflect a self-security state of network elements of a 6LoWPAN network for training, and establishes a 6LoWPAN network feature space. The present invention assigns the weights to the features and transfers zero points, to alleviate the bias caused by large and small impact factors and simplify calculation; realizes construction and update of a state data table of network elements by extracting the feature data of network elements in real time, thus forming a normal contour updated according to the real-time state of the network in the feature space of the 6LoWPAN network based on the clustering effect of a KNN algorithm; and the present invention improves the KNN algorithm and redefines a basis for judging the invasion, to meet the requirements for 6LoWPAN network intrusion detection.

Abstract: The present invention relates to a method for estimating clock frequency offsets of industrial wireless sensor networks based on timing response. In the method, a data packet is sent from a node to be synchronized to a reference node. After the reference node receives the data packet, it replies an acknowledgement after a timing response interval, which is mapped according to a sequence number of the data packet. After communication and interaction for multiple times, a relative frequency offset and a fixed delay between node clocks can be estimated by the node to be synchronized without exchanging timestamp information. The present invention does not need to receive or send messages specially used for time synchronization parameter estimation, which realizes a long-term tracking of clock frequency offset with a low computation cost and reduces communication overhead and energy consumption.

Abstract: The present invention relates to a frequency offset estimation method for average consensus-based clock synchronization, and belongs to the technical field of wireless sensor networks. According to the method, in combination with distributed one-way broadcast characteristics, solving of maximum likelihood estimation is converted into a linear optimization problem, and a relative frequency offset estimation value is obtained by adopting an iterative method. By applying the estimation value to the compensation of logic clock parameter between nodes, an effect of keeping logic clocks of network nodes consistent can be achieved.

Abstract: A method for content caching in information centric network virtualization includes receiving, by a first node, a first data packet; in response to a cache distance identifier hop of the first data packet being less than a preset maximum cache distance, setting hop=hop+1 and sending the first data packet to a next node by the first node; in response to the hop being not less than the preset maximum cache distance and there being available cache space in the first node, setting hop=0, storing the first data packet, and sending the first data packet to the next node by the first node. The node determines whether to cache a data packet based on the cache distance identifier of the data packet, which comprehensively considers the cache energy consumption caused by caching the data packet in the node and the transmission energy consumption caused by transmission of the data packet in the link, thereby effectively reducing the total energy consumption of the network.

Abstract: The present invention is intended to protect an industrial wireless communication method based on self-adaptive channel hopping within timeslot, which belongs to industrial wireless communication technology field. Aiming to solving existing problem that wireless devices can not correspondingly self-adaptive channel hopping according to environment changing, a method for making the two communication sides self-generate and execute channel switch when the preferred channel was interfered. The sender will monitor whether the channel is idle within SWTW before sending data through mechanisms such as CCA or non-persistent CSMA. If the channel is still busy till the SWTW times out, the sender will give up sending data and implement channel switching control command by considering this communications channel as interfered. If no packets were received till the RWTW time-outs, the receiver will thinks the communication channel was interfered and automatically implement channel switching control commands.

Abstract: The present invention is intended to protect an industrial wireless communication method based on self-adaptive channel hopping within timeslot, which belongs to industrial wireless communication technology field. Aiming to solving existing problem that wireless devices can not correspondingly self-adaptive channel hopping according to environment changing, a method for making the two communication sides self-generate and execute channel switch when the preferred channel was interfered. The sender will monitor whether the channel is idle within SWTW before sending data through mechanisms such as CCA or non-persistent CSMA. If the channel is still busy till the SWTW times out, the sender will give up sending data and implement channel switching control command by considering this communications channel as interfered. If no packets were received till the RWTW time-outs, the receiver will thinks the communication channel was interfered and automatically implement channel switching control commands.