Joint Computation and Communication Cooperation for Mobile Edge Computing

This paper proposes a novel joint computation and communication cooperation approach in mobile edge computing (MEC) systems, which enables user cooperation in both computation and communication for improving the MEC performance. In particular, we consider a basic three-node MEC system that consists of a user node, a helper node, and an access point (AP) node attached with an MEC server. We focus on the user's latency-constrained computation over a finite block, and develop a four-slot protocol for implementing the joint computation and communication cooperation. Under this setup, we jointly optimize the computation and communication resource allocation at both the user and the helper, so as to minimize their total energy consumption subject to the user's computation latency constraint. We provide the optimal solution to this problem. Numerical results show that the proposed joint cooperation approach significantly improves the computation capacity and the energy efficiency at the user and helper nodes, as compared to other benchmark schemes without such a joint design.Comment: 8 pages, 4 figure

Stock Prices and the Macro Economy in China

This paper analyses the relationship between stock prices and the Chinese macro economy measured by the level of GDP. There are many possible channels of influence between these two variables, channels which may operate in either direction. There are also many theories relevant to these interrelationships. Rather than explicitly testing theories, we focus on the empirical nature of this relationship which we analyse in the context of a VAR/VEC model which allows for two-way influences but is agnostic about the particular theoretical underpinnings. We apply tests for stationarity and cointegration and find that there is a long-run, cointegrating relationship between stock prices and GDP. We estimate a VEC model and use it to analyse both short-run and long-run causality as well as to generate impulse response functions (IRFs). We find that there is strong evidence of long-run causality from the economy to the stock market but not vice versa. We also find modest but weaker evidence of a similar short-run effect. These are borne out by the IRFs which show a small and weak link from the stock market to the economy but a stronger and much more substantial effect in the opposite direction. We rationalise our results in terms of the relatively small size of China’s stock market.stock prices, output, China