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The multipath error is the primary pseudorange measuring error factor in Compass system, in dual-frequency positioning mode, it is difficult to be eliminated by modeling methods, and on the contrary, it is always amplified because of the combination of measuring error. As a result, certain kind of user terminal has lower vertical positioning precision under dual-frequency mode than under single-frequency mode. This paper makes simulation of the impact of multipath error on pseudorange UERE under single-band mode and dual-band mode, obtains the interrelation of ionosphere modeling error, multipath error and the vertical positioning precision of single-band and dual-band respectively. This paper extracts multipath error in pseudorange of GEO and IGSO satellite by pseudorange carrier phase combination method, and uses the ionosphere delay calculated by dual-band carrier phase measurements as a benchmark, makes assessment of the ionosphere delay calculated by dual-band pseudorange combination method and ionospheric delay model correction method, analyses the amount of error correction brought into the Compass system by pseudorange of distinct orbit satellite. Data processing results show that, under current multipath mitigation measures, the pseudorange multipath error will cause that the error of GEO satellite ionosphere delay correction measured by dual-band is larger than by single-band, make a reasonable interpretation of the phenomena that dual-band vertical positioning accuracy is lower than single-band vertical positioning accuracy, and the ionospheric delay correction errors brought by pseudorange multipath error of GEO satellites are greater than the IGSO satellites, verify the phenomenon of “standing multipath error” brought by GEO satellite orbital characteristics.

In the wireless sensor networks (WSNs), the battery energy of sensor node is very limited. So, how to use energy of sensor node effectively to prolong the lifetime of WSNs is a challenge. Now, we mostly adopt the routing algorithm is based on clustering, the drawback of this algorithm is rate of utilization of cluster-head node energy is very high and the network lifetime rapidly shorter. This paper puts forward a kind of routing algorithm in WSNs, it is Distributed Energy Balancing Routing algorithm (DEBR), this algorithm through energy costs (EC) control the rate of utilization of each sensor node in WSNs, thus dump energy of each sensor node is balance and prolong the lifetime of wireless sensor networks.

For undirected simple networks G with perfectly reliable vertices and unreliable edges, we consider the Pair-Connected Reliability of G for which edges fail independently of each other with a constant probability p. The Pair-Connected Reliability of G denoted by PC(G , p), is defined to be the expected number of pairs of vertices that keep connected in network G. Using the definition of probability Random Events that basing on the Path Sets and Cut Sets between arbitrary pair connected nodes, we give a approximate calculating method to get the upper and lower bound on Pair-Connected Reliability with edges failure and find the concise bounds expression of Complete-Networks K n.

With the application of satellite navigation becoming more and more widely, increasingly complex electromagnetic environment needs to be dealt with. The anti-jamming capabilities of satellite navigation receivers have got more and more attention, whether in the field of military or civilian. The most important and most widely used class of anti-jamming technology is pre-correlation anti-jamming mean. However, the upper bound of overall anti-jamming capability is less studied when the anti-jamming filter inserted into a digital satellite receiver. In this paper the upper bound of anti-jamming capability for pre-correlation anti-jamming receivers is studied. First of all, the quantization loss is theoretically derived, when the input interference is a continuous wave (CWI). A near-optimal quantization interval criterion is proposed through analyzing the minimize quantization loss. Also, according to the calculation of signal-to-noise ratio (SNR) chain in the receiver, the maximum anti-jamming capability is obtained under the constraint of specified quantization bits and quantization interval. The analysis of the upper bound of anti-jamming capability is very important for the design of anti-jamming receivers, and also improves the anti-jamming theory for all spread spectrum signal receivers.