Description
The objective of the activity is to design and develop pre-coding techniques enabling up to 50% useful throughput increase of flexible satellite broadband systems. An emulator shall be developed to demonstrate the achieved throughput improvements.
Targeted Improvements: To increase the useful (i.e. billable) throughput of a satellite broadband system (up to 50%).
Description: The capability to flexibly allocate on-board resources over the service coverage is becoming a must for future broadband multi-beam satellites. Previous and current systems have shown that in large multi-beam satellites the demand in some beams greatly exceeds the available capacity (hot-spots) while in others the situation is the opposite (cold-spots).
This raises a paradoxical scenario where demand is left unmet in the hot-spots while capacity is left unused in the cold-spots. The consequence for the satellite operator is twofold: (1) a loss of the revenue corresponding to the unmet demand plus (2) the loss of the investment in the unused capacity.
The primary goal of flexibility is then to solve this paradox and maximize the amount of system capacity that is actually used (i.e. sold) by allocating it where needed. Flexibility may be implemented in a number of ways in particular the flexible allocation of bandwidth (irregular frequency re-use) and the flexible allocation of time (beam hopping). Unfortunately, in certain scenarios the performance of these two approaches is heavily degraded by the self-interference generated by the system.
Such interference may be estimated at each user terminal and reported back to the gateway, which can then exploit this information and pre-compensate for the interference by precoding. Previous studies have shown that a theoretical throughput increase of 50% can be achieved. However, the effectiveness of precoding techniques is sensitive to real-life link impairments which must be properly accounted for in their design.In this activity, robust pre-coding techniques for beam hopping and irregular frequency re-use schemes shall be developed taking into account all impairments of a satellite link.
The achieved performance improvement shall be demonstrated in a number of scenarios. Suchscenarios shall be first identified. To this aim a high throughput satellite broadband mission shall be defined including coverage,target flat throughput and power/mass satellite budgets. A number of traffic profiles shall also be generated to cover geographicaland temporal flexibility. As part of the scenario definition, the activity shall select the appropriate precoding techniques for the different flexibility approaches (i.e. beam-hopping and irregular frequency re-use).
The performance assessment shall not only be in terms of system capacity/throughput, but also in terms of offered flexibility in accommodating variable traffic demands over the coverage area. Therefore, a performance metric reflecting the traffic satisfaction factor for a system with and without precoding shallbe compared.
Finally, a technology roadmap for space segment supporting aggressive frequency re-use and a technology roadmap forground segment supporting precoding shall be derived.The activity shall develop a system emulator to support the design of the precoding techniques and to demonstrate their performance. The emulator shall take into account all relevant link impairments such as channel estimation and synchronization issues.
Tender Specifics