The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Although the base station processing and the majority of the protocols of the wireless systems are standardized by 3GPP, the receiver architecture and implementation remain vendor-dependent. The receiver design should fulfill computational efficiency requirements, and be evaluated in practical simulators or emulators that are compliant with real-world wireless standards. In this paper, we provide...
Thorough investigation of the Cloud-RAN (C-RAN) architecture has recently shown that C-RAN can bring advanced cooperated and coordinated processing capabilities as well as the multiplexing gains toward future radio access networks. The baseband processing of each base station instance can now be flexibly split into smaller functional components, that can be placed either at remote radio units (RRUs)...
In this demo, we describe the realization of cloud radio access network (C-RAN) prototype using OpenAirInterface (OAI) software and commodity hardware. The deployment of the centralized baseband processing on the remote cloud center (RCC), and the remote radio units (RRU), connected over Ethernet fronthaul is demonstrated. Further, the demo illustrates the flexibility in deploying several cellular...
This paper considers the problem of jointly estimating two independent continuous-valued parameters sent over a Gaussian multiple-access channel (MAC) subject to the mean square error (MSE) as a fidelity criterion. We generalize the parameter modulation-estimation analysis techniques proposed by Merhav in 2012 to a two-user multiple-access channel model to obtain outer bounds to the achievable region...
Maximum-likelihood (ML) receivers are optimum receivers for MIMO systems, but their complexity grows exponentially with the modulation order of the codeword and the number of spatial layers. The Reduced Complexity ML (R-ML) receivers based on low complexity adaptation of the max-log MAP detector and reduction of searching space are a good compromise to satisfy complexity-performance trade-off. In...
Handover procedure in LTE/LTE-A has been radically evolved when compared to the previous 3GPP standards. In particular, X2 handover is introduced to allow neighboring eNBs to handle the user mobility without the involvement of the core network. While most of the application could considerably benefit from the X2 handover performance improvement, delay breakdown and impact of parameters from the UE...
This chapter provides an overview of the OpenAirInterface (OAI) both in terms of its hardware and software elements and its usage in cognitive wireless networking applications based on long term evolution (LTE) technology. In particular, we show a design of a cognitive radio systems in the LTE framework that enables the deployment of cognitive radio in licensed bands, with no hardware modification...
5G mobile networks will very likely include features that allow for a dynamic spectrum access (DSA) in order to exploit spectrum holes of a primary system. The efficient utilization of spectrum holes with minimum impairment of the primary system requires a waveform with a very low adjacent channel leakage ratio as well as robustness to time and frequency offsets. One of the approaches for new waveforms...
We describe a channel sounding measurement campaign for cellular broadband wireless communications with high speed trains that was carried out in the context of the project CORRIDOR. The campaign combines MIMO and carrier aggregation to achieve very high throughputs. We compare two different scenarios, the first one reflects a cellular deployment, where the base station is about 1km away from the...
This paper considers a Gaussian network where N half-duplex multiple-antenna relays assist the communication between a source and a destination. A novel antenna switching policy is proposed, where each relays' antenna can be configured to either receive or transmit independently of the others. The rate achieved by noisy network coding is shown to be to within a constant gap from the cut-set bound,...
For time division duplexing (TDD) systems, the physical channel in the air is reciprocal for uplink (UL) and downlink (DL) within the channel coherence time. However when the transceivers' radio frequency (RF) hardware is taken into consideration, TDD channel reciprocity no longer holds because of the non-symmetric characteristics of RF transmit and receive chains. Relative calibration has been proposed...
This paper studies the sum-capacity of the Multiple Input Single Output (MISO) Gaussian broadcast channel where K single-antenna users are served by a base station with N antennas, with N < K. The generalized Degrees-of-Freedom (gDoF) for this system is derived as the solution of a Maximum Weighted Bipartite Matching (MWBM) problem, where, roughly speaking, each of the N transmit antennas is assigned...
In this paper, we propose a novel architecture for next generation cellular networks that enables collaborative forwarding at Layer 2 among adjacent eNBs with the aid of enhanced user equipment (UE) devices, that act voluntarily as packet forwarders. Therefore, legacy UEs are leveraged as active network elements being capable of operating simultaneously over multiple base stations (eNBs). To this...
In this work, we demonstrate and validate a novel architecture for next generation cellular networks that enables collaborative forwarding at Layer 2 among adjacent eNBs with the aid of enhanced user equipment (UE) devices, that act voluntarily as packet forwarders. We introduce an evolved-UE (eUE) which is capable of operating simultaneously over multiples eNBs in order to enable reliable multi-hop...
TV White Spaces (TVWS) technology allows wireless devices to opportunistically use locally-available TV channels enabled by a geolocation database. The UK regulator Ofcom has initiated a pilot of TVWS technology in the UK. This paper concerns a large- scale series of trials under that pilot. The purposes are to test aspects of white space technology, including the white space device and geolocation...
In ISIT2012 Brahma, Özgür and Fragouli conjectured that in a half-duplex diamond relay network (a Gaussian noise network without a direct source-destination link and with N non-interfering relays) an approximately optimal relay scheduling (achieving the cut-set upper bound to within a constant gap uniformly over all channel gains) exists with at most N + 1 active states (only N + 1 out of the 2N possible...
TV White Spaces technology is a means of allowing wireless devices to opportunistically use locally-available TV channels (TV White Spaces), enabled by a geolocation database. The geolocation database informs the device of which channels can be used at a given location, and in the UK/EU case, which transmission powers (EIRPs) can be used on each channel based on the technical characteristics of the...
This paper studies the two-user interference channel with unilateral source cooperation, which consists of two source-destination pairs that share the same channel and where one full-duplex source can overhear the other source through a noisy in-band link. Novel outer bounds of the type 2R1 + R2 and R1 + 2R2 are developed for the class of injective semi-deterministic channels with independent noises...
This paper considers the two-user Gaussian Causal Cognitive Interference Channel (GCCIC), which consists of two source-destination pairs that share the same channel and where one full-duplex cognitive source can causally learn the message of the primary source through a noisy link. The GCCIC is an interference channel with unilateral source cooperation that models practical cognitive radio networks...
This paper studies the Gaussian interference channel with unilateral generalized feedback, a system where two source-destination pairs share the same channel and where one full-duplex source overhears the other through a noisy in-band link. A superposition coding scheme is shown to achieve a known outer bound to within a small number of bits for a subset of the weak interference regime, outside which...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.