Cooperative Radar and Communications Signaling: The Estimation and Information Theory Odd Couple

We investigate cooperative radar and communications signaling. While each system typically considers the other system a source of interference, by considering the radar and communications operations to be a single joint system, the performance of both systems can, under certain conditions, be improved by the existence of the other. As an initial demonstration, we focus on the radar as relay scenario and present an approach denoted multiuser detection radar (MUDR). A novel joint estimation and information theoretic bound formulation is constructed for a receiver that observes communications and radar return in the same frequency allocation. The joint performance bound is presented in terms of the communication rate and the estimation rate of the system.Comment: 6 pages, 2 figures, to be presented at 2014 IEEE Radar Conferenc

Automated Spacecraft Communications Service Demonstration Using NASA's SCaN Testbed

The traditional paradigm for space mission operations relies on inefficient, highly scripted pre-planned activities between space communications & navigation service providers and user ground mission operations centers. Typically there is limited or non-existent automation capabilities on the user spacecraft for requesting space communications services, and on the provider network for request dispositioning and service provisioning. In the past, using these processes for space networks was sufficient with the relatively small number of user spacecraft requesting services. However, with an ever increasing number of satellites being launched to orbit, more complex event-driven science objectives, exploration missions involving collaborative platforms, and more distant missions, approaches that improve automation, flexibility and efficiency are needed. This paper describes NASA's recently completed on-orbit demonstration results of a new space communications service concept called User Initiated Service, and a discussion for infusing this innovation into operations

LTE performance evaluation with realistic channel quality indicator feedback

In the context of mobile communications, the availability of new services and mobile applications along with the constant evolution in terminals run up the need of higher data rates. In order to fulfill such expectations, mobile operators are continually optimizing and upgrading their networks. The Long Term Evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) seems to be the path to follow in a very short term. The objective of this project is to study the behaviour of the radio resource assignment in LTE under realistic conditions. The scheduling is a key process in the functioning of the radio interface. Thus, two types of schedulers can be identified, the opportunistic, where the scheduler considers the state of the radio channel to make the best allocation possible, and the non-opportunistic, where the allocation has no knowledge of the radio channel‘s state. As the opportunistic option adapts to the radio channel conditions it requires the transmission of a certain level of signalling from users informing about how the channel evolves along time. One of the objectives of this project is to evaluate the system performance under different degrees of feedback. To do this, different CQI reporting methods have been programmed and simulated. So, to achieve this objective it is obvious that a second one is necessary: program and simulate in a more realistic way the LTE radio channel. The followed methodology has been fundamentally the programming of different mathematical models and algorithms, as well as its simulation. In concrete, one of the main tasks in this work has been to extent a software platform of the research group Wicomtec to obtain more realistic results through dynamic simulations over a dynamic radio channel