Linear Precoding performance analysis in a Broadband satellite system with a 2-color dual-polarization reuse scheme (original) (raw)

Precoding With Received-Interference Power Control for Multibeam Satellite Communication Systems

Frontiers in Space Technologies, 2021

Zero-Forcing (ZF) and Regularized Zero-Forcing (RZF) precoding are low-complexity sub-optimal solutions widely accepted in the satellite communications community to mitigate the resulting co-channel interference caused by aggressive frequency reuse. However, both are sensitive to the conditioning of the channel matrix, which can greatly reduce the achievable gains. This paper brings the attention to the benefits of a design that allows some residual received interference power at the co-channel users. The motivation behind this approach is to relax the dependence on the matrix inversion procedure involved in conventional precoding schemes. In particular, the proposed scheme aims to be less sensitive to the user scheduling, which is one of the key limiting factors for the practical implementation of precoding. Furthermore, the proposed technique can also cope with more users than satellite beams. In fact, the proposed precoder can be tuned to control the interference towards the co-c...

Generic Optimization of Linear Precoding in Multibeam Satellite Systems

Ieee Transactions on Wireless Communications, 2012

Multibeam satellite systems have been employed to provide interactive broadband services to geographical areas under-served by terrestrial infrastructure. In this context, this paper studies joint multiuser linear precoding design in the forward link of fixed multibeam satellite systems. We provide a generic optimization framework for linear precoding design to handle any objective functions of data rate with general linear and nonlinear power constraints. To achieve this, an iterative algorithm which optimizes the precoding vectors and power allocation alternatingly is proposed and most importantly, the proposed algorithm is proved to always converge. The proposed optimization algorithm is also applicable to nonlinear dirty paper coding. As a special case, a more efficient algorithm is devised to find the optimal solution to the problem of maximizing the proportional fairness among served users. In addition, the aforementioned problems and algorithms are extended to the case that each terminal has multiple co-polarization or dual-polarization antennas. Simulation results demonstrate substantial performance improvement of the proposed schemes over conventional multibeam satellite systems, zero-forcing and regularized zero-forcing precoding schemes in terms of meeting the traffic demand. The performance of the proposed linear precoding scheme is also shown to be very close to the dirty paper coding.

Joint Precoding with Flexible Power Constraints in Multibeam Satellite Systems

2011 IEEE Global Telecommunications Conference - GLOBECOM 2011, 2011

In conventional multibeam satellite systems, frequency and polarization orthogonalization have been traditionally employed for mitigating interbeam interference. However, the paradigm of multibeam joint precoding allows for full frequency reuse while assisting beam-edge users. In this paper, the performance of linear beamforming is investigated in terms of meeting traffic demands. More importantly, generic linear constraints are considered over the transmit covariance matrix in order to model the power pooling effect which can be implemented through flexible traveling wave tube amplifiers (TWTAS) or multiport amplifiers. The performance of this scheme is compared against conventional spotbeam systems based on the rate-balancing objective. In this context, it is shown that significantly higher spectral efficiency can be achieved through beamforming, while flexible power constraint offers better rate-balancing.

Designing joint precoding and beamforming in a multiple gateway multibeam satellite system

2018 IEEE Wireless Communications and Networking Conference (WCNC), 2018

This paper aims to design joint on-ground precoding and on-board beamforming of a multiple gateway multibeam satellite system in a hybrid space-ground mode where full frequency reuse pattern is considered among the beams. In such an architecture, each gateway serves a cluster of adjacent beams such that the adjacent clusters are served through a set of gateways that are located at different geographical areas. However, such a system brings in two challenges to overcome. First, the inter-beam interference is the bottleneck of the whole system and applying interference mitigation techniques becomes necessary. Second, as the data demand increases, the ground and space segments should employ extensive bandwidth resources in the feeder link accordingly. This entails embedding an extra number of gateways aiming to support a fair balance between the increasing demand and the corresponding required feeder link resources. To solve these problems, this study investigates the impact of employing a joint multiple gateway architecture and onboard beamforming scheme. It is shown that by properly designing the on-board beamforming scheme, the number of gateways can be kept affordable even if the data demand increases. Moreover, Zero Forcing (ZF) precoding technique is considered to cope with the inter-beam interference where each gateway constructs a part of block ZF precoding matrix. The conceived designs are evaluated with a close-to-real beam pattern and the latest broadband communication standard for satellite communications. Index Terms-Multibeam satellite systems, multiple gateway systems, on-board beamforming, precoding techniques.

Linear and nonlinear techniques for multibeam joint processing in satellite communications

Eurasip Journal on Wireless Communications and Networking, 2012

Existing satellite communication standards such as DVB-S2, operate under highly-efficient adaptive coding and modulation schemes thus making significant progress in improving the spectral efficiencies of digital satellite broadcast systems. However, the constantly increasing demand for broadband and interactive satellite links emanates the need to apply novel interference mitigation techniques, striving towards Terabit throughput. In this direction, the objective of the present contribution is to investigate joint multiuser processing techniques for multibeam satellite systems. In the forward link, the performance of linear precoding is investigated with optimal nonlinear precoding (i.e., dirty article coding) acting as the upper performance limit. To this end, the resulting power and precoder design problems are approached through optimization methods. Similarly, in the return link the concept of linear filtering (i.e., linear minimum mean square error) is studied with the optimal successive interference cancelation acting as the performance limit. The derived capacity curves for both scenarios are compared to conventional satellite systems where beams are processed independently and interbeam interference is mitigated through a four color frequency reuse scheme, in order to quantify the potential gain of the proposed techniques.

Frame based precoding in satellite communications: A multicast approach

2014 7th Advanced Satellite Multimedia Systems Conference and the 13th Signal Processing for Space Communications Workshop (ASMS/SPSC), 2014

In the present work, a multibeam satellite that employs aggressive frequency reuse towards increasing the offered throughput is considered. Focusing on the forward link, the goal is to employ multi-antenna signal processing techniques, namely linear precoding, to manage the inter-beam interferences. In this context, fundamental practical limitations, namely the rigid framing structure of satellite communication standards and the on-board per-antenna power constraints, are herein considered. Therefore, the concept of optimal frame based precoding under per-antenna constraints, is discussed. This consists in precoding the transmit signals without changing the underlying framing structure of the communication standard. In the present work, the connection of the frame based precoding problem with the generic signal processing problem of conveying independent sets of common data to distinct groups of users is established. This model is known as physical layer multicasting to multiple cochannel groups. Building on recent results, the weighted fair per-antenna power constrained multigroup multicast precoders are employed for frame based precoding. The throughput performance of these solutions is compared to multicast aware heuristic precoding methods over a realistic multibeam satellite scenario. Consequently, the gains of the proposed approach are quantified via extensive numerical results.

Capacity potential of mobile satellite broadcasting systems employing dual polarization per beam

2010 5th Advanced Satellite Multimedia Systems Conference and the 11th Signal Processing for Space Communications Workshop, 2010

The paper carries out a preliminary assessment of how mobile satellite broadcasting (MSB) systems can increase their capacity potential with a high degree of flexibility and, at the same time, remain on par with wireless terrestrial counterparts. As argued in this work, a promising way forward in this regard is the migration from the conventional single polarization per beam to an advanced dual polarization per beam architecture, also benefitting from recent advancement in multibeam antenna techniques. This work summarizes results of recent studies on dual polarization MSB from a system, interference, antenna, channel, capacity, and FEC uncoded MIMO performance perspective, highlighting along the course the major milestones and challenges.

Joint Precoding and On-Board Beamforming for Multiple gateway Multibeam Satellite Systems

2017

This paper aims to design joint precoding and onboard beamforming of a multiple gateway multibeam satellite system, either in a hybrid space-ground mode, or in a totally on-board one. In such an architecture, with employing high throughput full frequency reuse pattern over both user and feeder links, each gateway serves a cluster of adjacent beams such that the adjacent clusters are served through a set of gateways that are located at different geographical areas. However, such a system brings in two challenges to overcome. First, the interference in both user and feeder links is the bottleneck of the whole system and applying interference mitigation techniques becomes necessary. Second, as the data demand increases, the ground and space segments should employ extensive bandwidth resources in the feeder link accordingly. This entails embedding an extra number of gateways aiming to support a fair balance between the increasing demand and the corresponding required feeder link resourc...

BER Performance of Multibeam Satellite Systems with Tomlinson-Harashima Precoding

2009 IEEE International Conference on Communications, 2009

A multibeam satellite system can be modelled as a multiple-input multiple-output (MIMO) system with an interbeam interference matrix that is derived from the positions of the users in the different beams. This way it is possible to apply precoding techniques, such as Tomlinson-Harashima precoding (THP), to mitigate the interference. This paper presents an analytical framework to model the interference by a simple and effective parameter, which enables to assess the uncoded bit error rate (BER) of THP in such a scenario, and to derive useful hints on the optimization of the overall system capacity.

Joint precoding and predistortion techniques for satellite telecommunication systems

2005

We analyze the application of Tomlinson-Harashima precoding to satellite transmission. Precoding counteracts channel dispersion at the price of increasing the dynamic range of the signal to be transmitted. This conflicts with the requirements of typical satellite transmission, where amplifiers with nonlinear characteristics are used, and their incoming signal is desired to present a reduced dynamic range. We propose fractional predistortion as a valid countermeasure against the effects of the nonlinear amplifier. Simulations allow us to obtain the performance of the proposed scheme when applied to two typical satellite propagation environments and compare it to an equivalent scheme using standard Decision-Feedback Equalization. We conclude that a system using Predistortion is more sensitive to the effects of satellite transmission-related nonlinearities than the equivalent DFE system.