Research On High-efficient Data Transmission Mechanisms Based On Compressed Sensing And Network Coding In Wireless Network

The appearance of wireless network technology provides effective solutions for military communication,temporary communication,earthquake relief,bio-medical,smart roads,intelligent conference and family entertainment areas.Recently,the diversity of business of wireless network is increasingly,and the delivery of lots of business information puts forward higher requirements on wireless network performance.This requires that future wireless network have better transmission efficiency.The research and design of high-efficient data transmission mechanisms in wireless network is of great theoretical and practical significance.Compressed Sensing(CS)can sample sparse signals at a far lower rate than the Nyquist sampling theorem.For the sparse signals,the original signal can be accurately reconstructed from a small number of observations that we only need storage or transmit.Compared with the traditional transmission systems,the CS based data transmission systems can effectively reduce the number of required packets processed on the premise that the reconstruction signal quality is relatively good,thus improving the transmission performance in wireless network.Once it is applied in practice successfully,CS theory will invigorate new vitality to wireless network.As one of the crucial issues,the measurement matrix design is direct relation to the specific practical application of CS theory's success or failure.Better measurement matrix leads to smaller number of measurements to achieve the same reconstruction performance.On the other hand,network coding technology allows intermediate nodes to perform the encoding operation during several packets from different flows.It is no longer limited to the store and forward operation in traditional network data processing to improve the data transmission performance in wireless network.Based on the above ideas,this dissertation studies the high-efficient data transmission mechanisms in wireless network.For the single data-flow transmission,it devotes itself to find a kind of high-performance measurement matrix which is easy in hardware realization in order to achieve the high-efficient sampling and measurement of the source data,thus improving the single data-flow transmission performance in wireless network.For the multiple data-flow transmission,this dissertation devotes itself to find high-efficient network coding-aware routing algorithms under different metric optimization framework for network performance in order to improve the multiple data-flow transmission performance in wireless network.The main works and research achievements of the dissertation are as follows:1.The performance of data measurement matrix directly relates to the number of required packets reconstructed in a wireless network,and traditional random measurement matrix is not easy in hardware realization and limited in practical application.Aiming at above problems,from the promotion and application of the CS theory,this dissertation constructs a Binary Sequence Family based Deterministic Measurement Matrix(BSFDMM).The coherence of the proposed matrix BSFDMM is derived to be smaller than the corresponding Gaussian random matrix and Bernoulli random matrix.Theoretical analysis and simulation results show that the proposed matrix BSFDMM can obtain better reconstruction results than the corresponding Gaussian random matrix and Bernoulli random matrix.The proposed matrix BSFDMM can make the hardware realization convenient and easy by means of linear feedback shift register(LFSR)structures,thus being conductive to practical compressed sensing.2.Existing coding aware routing protocols don't consider the queue state of the coding node in packet coding algorithm,and most of the existing algorithms assume that all flows participating in the network coding have equal rate.Aiming at above problems,this dissertation proposes an Optimal Queue Management based Coding Aware Routing algorithm(OQMCAR).This algorithm optimizes the network throughput performance,decides packets according to the queue-length based threshold policy instead of the regular opportunistic network coding policy at coding node.Taking advantage of the CS theory that the original signal can be accurately reconstructed from a small number of observations,this algorithm introduces network throughput training phase before data transmission phase to make the coding node obtain the optimal threshold for the queue-length based threshold policy.Experimental results show that the proposed algorithm OQMCAR can have higher throughput gain,as well as achieve lower average end-to-end delay than the current schemes using opportunistic network coding in any traffic rates.3.Existing opportunistic network coding scheme can degrade the contribution of network coding to delay performance,while it is significant to reduce packet delivery delay for real-time applications in a wireless network.This dissertation proposes a Buffer management based Low-delay data transmission algorithm in Coding Aware Routing(BLCAR).This algorithm optimizes the network delay performance,decides packets according to the queue-length based threshold policy at coding node,designs the packet metric APWD(Average Packet Waiting Delay)which can characterize the network delay performance,and introduces network delay training phase before data transmission phase to make the coding node obtain the optimal threshold for the queue-length based threshold policy by borrowing the CS theory to derive that the network long-term delay performance can be characterised from the APWD of a small part packets.Theoretical analysis and simulation results show that the proposed algorithm is effective.The proposed algorithm BLCAR can see a significant drop in packet delivery delay,as well as achieve higher throughput and lower packet loss ratio than the traditional opportunistic network coding policy in network congestion.4.Existing opportunistic network coding scheme can degrade the contribution of network coding to jitter performance,and most of the existing coding-aware routing algorithms assume that all flows participating in the network coding have equal rate.Aiming at above problems,from the multimedia applications' reality in a wireless network,this dissertation proposes a Buffer management based Low-Jitter data transmission algorithm in Coding Aware Routing(BLJCAR).This algorithm optimizes the network jitter performance,designs the packet metric AVPWD(Average Variation in Packet Waiting Delay)which can characterize the network jitter performance at coding node,andintroduces network jitter training phase before data transmission phase by borrowing the CS theory to derive that the data-flow long-term jitter performance can be reflected from the AVPWD of a small number of packets.Based on the characteristic that the sequence of received packet affects the jitter performance,this dissertation uses the random geometric graph theory to derive the upper and nonzero lower bounds of threshold searching range in the queue-length based threshold policy.Experimental results show that the proposed algorithm BLJCAR improves the network jitter performance,as well as outperforms the traditional opportunistic network coding policy in terms of network throughput,average end-to-end delay and packet loss ratio in network congestion in any traffic rates.