Giorgia Parca

Satellite communication and propagation experiments through the alphasat Q/V band Aldo Paraboni technology demonstration payload

Current high-throughput satellite (HTS) systems for broadband distributed user access are designed following two main concepts: The use of Ka band radio frequency (RF) links both for the forward and for the return link; this choice is due to the congestion of lower frequency bands and to the relatively large bandwidth available in the Ka band. Moreover, the RF technology in the Ka band is mature [1], [2]. The use of multispot coverage: this technique is largely applied to increase the system throughput through frequency reuse and system reconfigurability [2], [3].

Q/V-band satellite communication experiments on channel estimation with Alphasat Aldo Paraboni P/L

The Alphasat Aldo Paraboni communication experimental campaign is based on a transparent QIV band transponder hosted as a piggy-back on a GEO satellite. Together with the transparent payload, two beacons having European coverage, one in Ka-band and one in QIV-band, are used to perform propagation experiments. The transparent payload has three spot beams, two over Italy and one over Austria. The University of Rome Tor Vergata-CTIF Italy is the Principal Investigator for the communication experiments and is in charge of operating the payload and the Italian ground stations. The Alphasat Aldo Paraboni experiment is an important step toward the development of future High Throughput Satellite (HTS) systems, able to support hundreds of gigabit/s or terabit/s connectivity. These systems will require: a) use of frequency bands beyond Ka (i.e. Q, V and W bands); b) enhanced frequency reuse; c) use of Propagation Impairments Mitigation Techniques (PIMT). Alphasat Aldo Paraboni payload allows us to perform, for the first time, communication experiments over a Q/V band satellite link with adaptive PIMT, testing: Channel Estimation, Adaptive Coding and Modulation (ACM), up-link power control (ULPC) and space diversity. This paper presents the first results of the communication experiments campaign.

Radio-over-Fiber (RoF) Techniques for Broadband Wireless LAN

Radio-over-fiber (RoF) techniques are attractive for realizing high performance integrated networks. The growth of mobile and wireless communications fuels increasing demand for multimedia services with a guaranteed quality of service. This requires realization of broadband distribution and access networks. Within this framework, RoF schemes can be applied for realizing seamless wireless networks since they allow for the easy distribution of microwaves and millimeter waves over long distances along optical fibers. Some of the applications of RoF technology include cellular networks, satellite communications, multipoint video distribution services (MVDS), mobile broadband system (MBS), wireless LANs over optical networks.

Alphasat Aldo Paraboni payload IOT campaign and status after the first year of operation

The Alphasat satellite was launched on 25 July 2013. The Aldo Paraboni technology demonstration payload, funded by ASI under ESAs ARTES Programme, was embarked as an hosted payload on Alphasat. This Technology Demonstration Payload (identified as TDP5 and recently renamed “Aldo Paraboni”) was implemented under an ESA contract awarded in co-contractorship to Space Engineering and Thales Alenia Space Italia (TAS-I) which conceived the experimental mission and industrialised the subsystems. The Aldo mission is composed of two main elements: a Communication Experiment mission, which aims at assessing the performance of communication links at Q/V Bands; and a Scientific Experiment mission implemented through two beacons at Ka and Q Bands, which aims at characterizing propagation phenomena at these frequencies. During the In Orbit Test campaign of the above two mission components, TDP5 demonstrated compliance to the requirements and the nominal conditions of the Payload. The main topics of this paper are the description of the In Orbit Test requirements and the discussion of tests results. The good health of the Payload is demonstrated by the agreement of the results with the predictions that were calculated on the basis of the results of the on ground test campaign. The Commissioning and IOT campaign of Aldo Paraboni was performed over 3 distinct sessions: · Commissioning: 17-18 September 2013 · IOT Part 1: 10-18 October 2013 · IOT Part 2: 4-8 November 2013 This work is only related to the verification of the performance of the space segment, the Q/V-Band Payload, also referred to as the TDP5. TDP5 stands for Technical Demonstrator Payload #5 and it is formally the 5th experimental (i.e. technological demonstrator) hosted payload of the Alphasat programme.

Experimental assessment of optimal ACM parameters in Q/V-band satellite communication

Broadband satellite communication systems, with their global access and broadcasting capabilities, are assuming an increasing relevance in the framework of modern Information Society. These systems could greatly benefit from the use of Extremely High Frequency (EHF); in particular “beyond Ka-band” frequencies can provide the advantage of large bandwidth availability but also smaller antenna size for a fixed gain, or conversely, higher antenna gain for a fixed size. One of the main drawback that limits the use of these frequencies is represented by the strong impairments caused by the lower part of the atmosphere; research activities on techniques for propagation impairments mitigation are needed, in order to dynamically adapt the system to the channel conditions; in particular Adaptive Coding and Modulation (ACM), Data Rate Adaptation (DRA), up-link power control (ULPC), spatial diversity (both using classical site diversity approach or smart gateways approach) and on-board adaptive power allocation can be efficiently adopted to improve EHF satellite systems performance. At present the use of Ka-band is the benchmark for broadband satellite communications commercial application; higher bands are under scientific investigation; in particular Italian Space Agency started an experimental campaign on Q/V band based on Alphasat “Aldo Paraboni” P/L; in this paper, the authors will report the latest results of such experiments, with a specific focus on ACM techniques optimization.

Pump depletion measurement under Modulation Instability conditions

Modulation Instability (MI) is a nonlinear instable phenomenon arising in dispersive fiber optics under proper conditions. When a strong pump CW is injected a perturbation, initially negligible, undergoes amplification. In this paper we derive the instable regime theoretical conditions focusing on the pump depletion. This step is neglected in most of literature. Thus, we analyze MI effect as the interplay between a pump signal and a small perturbation propagating in anomalous dispersion regime. The pump depletion will lead, eventually, to the exhaustion of the nonlinear conditions. The CW power depletion is important for defining the optical gain offered by the fibre. In passing, the gain induced on small perturbation is measured, as well.

Analysis of satellite Q/V band channel errors based on Italian experimental campaign

High Throughput Satellite (HTS) systems still offer much less bandwidth per user with respect terrestrial broadband networks. In order to reach a very high throughput towards “Tbit/s connectivity”, an important breakthrough is needed in terms of bandwidth availability which can be offered by the use of Extremely High Frequency (EHF) bands (30–300 GHz). In particular, Q-V band (30–50 GHz) and W-band (70–110 GHz) offer very promising perspectives, being not used for commercial systems and offering a large part of the spectrum allocated for satellite services. However, it is well known that EHF band transmission through the atmosphere is subject to absorption and dispersive effects in amplitude and phase that have to be carefully characterized. In this framework, some mitigation techniques have to be analyzed and properly tuned in order to realize an efficient transmission. In this paper, the current experimental activities to support future EHF satellite communication systems are reported, with reference to the Italian Space Agency Q/V-band satellite communication experimental campaign. In particular, a new error model for QPSK modulation scheme has been developed from the experimental data. This error model can be used for the design of optimized channel coding and adaptive transmission schemes for Q/V band satellite channels.

The Italian assets for the CLOSEYE EU project: Cosmo-Skymed and Athena-Fidus satellite systems

The European Commission has identified the enhancement of integrated border management as one of the most important areas of interest. The 7th Framework Programme for research and development has been used since 2008 to improve the performance of the European Border Surveillance System (EUROSUR) and to test technical capabilities to curtail the flow of illegal immigrants reaching European coasts. In this sense, several initiatives have been fostered, CLOSEYE being one of them. In this paper a comprehensive description of the CLOSEYE project will be provided, highlighting the preliminary results obtained in this context by the synergic use of the two main Italian assets providing services in Satellite Earth Observation and Communications: COSMO-SkyMed constellation and Athena-Fidus satellite.

Validation of ground infrastructure in the framework of the ASI Q/V-band program

The Q/V Band program of ASI involves two main elements: the “Space Segment” and the “Mission Segment”. The Space Segment is represented by the Technology Demonstration Payload TDP#5, the “Aldo Paraboni” P/L. Financed by Italy through the ARTES-8 Program, it has been developed by the European Space Agency and implemented by italian space industries. It has been embarked as hosted payload on Alphasat satellite, and successfully launched on July 25th 2013. Alphasat is an INMARSAT Commercial Telecommunications Geosynchronous satellite, which uses the ESA developed Alphabus Platform and embarks four Technology Demonstration Payloads (TDPs). Among these TDPs, TDP#5 is devoted to the exploitation and the investigation of Q/V band communications. In conjunction with the Mission Segment (MS) the TDP#5 allows to carry out communications experiments (Propagation Impairment Mitigation Techniques - PIMT) at 40/50 GHz (Q/V-band) and propagation experiments at both 20 GHz (Ka-band) and 40 GHz (Q-band). The MS has been developed by ASI and consists of two transmitting/receiving Ground Stations (GS) and three control centers, for the execution of experiments in accordance with the requirements defined by the two Principal Investigators, appointed by ASI for the communication and propagation experiments. After the integration of all the elements composing the MS, the system test campaign started with the scope to demonstrate the correct operations through functional and performance tests. In particular, in addition to the propagation experiment verification, the campaign allows to test the Q/V band communication functions in the two payload configurations (i.e. in loopback mode and in cross mode).