Since the vehicles provided by current online car rental platforms are in the fixed price, there are some issues coming up such as unreasonable allocation of the vehicle resources, unreliable price that could not indicates the real market supply and demand timely, and generally low social welfare. Therefore, an auction based vehicle allocation and pricing mechanism for car rental was proposed. Firstly, a mathematical model and a social welfare maximization objective function were established by studying the model of online car rental issues. Secondly, based on the minimum cost and maximum flow algorithm, the optimal vehicle resource allocation algorithm was adopted among the rental vehicle allocation algorithms. Finally, in terms of the price calculation algorithms, a truthful VCG (Vickrey-Clarke-Groves) price algorithm was used to calculate the final price. As a result, compared with the traditional first-come-first-serving algorithms, the order success rate of the proposed scheme was increased by 20% to 30%, and the revenue was increased by about 30%. Theoretical analysis and experiment results show that the proposed mechanism has the advantages of optimizing vehicle allocation and flexible price strategy.

Tracking performance of traditional Global Positioning System (GPS) receiver in high dynamic environment is not ideal, a kind of GPS signal tracking algorithm based on carrier frequency assist phase was proposed to improve it. The traditional single tracking loop was replaced by frequency lock loop assisting phase lock loop, and intermediate-frequency signals in all tracking channel of receiver were processed using Kalman filter. According to many tracking channel pseudorange and pseudorange rate residual, comprehensive estimation for system state parameters was given. The system state equation and measurement equation of the Kalman filter were created and the tracking loop feedback was given. Tracking performance of the traditional scalar tracking mode was compared with that of the proposed method. The simulation results show that the GPS signal tracking algorithm based on carrier frequency assist phase gets into the steady state with 100 ms decreasing, the precision of position error is improved by 5 m, and the precision of velocity error is improved about 3 m/s. In the fast moving environment of receiver user, it can better handle the high dynamic signal.