Towards a Communicative City: Applying a New Framework for Understanding Communication and City

ince the Industrial Revolution with the productivity change brought by technology and modern mass media the distance between time and space has been shortened and the imagined urban community has been brought about Newspapers television and other mass media can not only have information functions but also unite and connect people into a whole through the communication network thus promoting the integration of urban communities However with the development of the internet and the explosive growth of urban population the rise of individualism has made the connection of traditional urban society declared unorganized and the traditional mass media has also lost its unified integration ability Bruhn 2011 8 The city has fallen into an unprecedented communication crisis and the construction of a coordinated and unified relationship between different individuals has become an urgent problem to be solved In other words the global expansion of the modernization process has led to the fragmentation of society and people find themselves in a modern world that has lost contact with the roots of communicability Internet technology which originally hoped to improve the efficiency of social communication has instead intensified social friction conflict and differentiation and communicability has become a significant dilemma faced by the media societ

Towards Dual-functional Radar-Communication Systems: Optimal Waveform Design

We focus on a dual-functional multi-input-multi-output (MIMO) radar-communication (RadCom) system, where a single transmitter communicates with downlink cellular users and detects radar targets simultaneously. Several design criteria are considered for minimizing the downlink multi-user interference. First, we consider both the omnidirectional and directional beampattern design problems, where the closed-form globally optimal solutions are obtained. Based on these waveforms, we further consider a weighted optimization to enable a flexible trade-off between radar and communications performance and introduce a low-complexity algorithm. The computational costs of the above three designs are shown to be similar to the conventional zero-forcing (ZF) precoding. Moreover, to address the more practical constant modulus waveform design problem, we propose a branch-and-bound algorithm that obtains a globally optimal solution and derive its worst-case complexity as a function of the maximum iteration number. Finally, we assess the effectiveness of the proposed waveform design approaches by numerical results.Comment: 13 pages, 10 figures. This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

Binary sampling ghost imaging: add random noise to fight quantization caused image quality decline

When the sampling data of ghost imaging is recorded with less bits, i.e., experiencing quantization, decline of image quality is observed. The less bits used, the worse image one gets. Dithering, which adds suitable random noise to the raw data before quantization, is proved to be capable of compensating image quality decline effectively, even for the extreme binary sampling case. A brief explanation and parameter optimization of dithering are given.Comment: 8 pages, 7 figure