MMSE Based Interference Processing For Satellite Broadcast Reception (original) (raw)

Reduced front-end reception requirements for satellite broadcast using interference processing

IEEE Transactions on Consumer Electronics, 2000

The problem of fixed satellite broadcast reception is considered. The possibility of reducing the requirements on the antenna front-end dimensions is investigated. Interference processing and mitigation techniques are employed to cope with the increased level of adjacent system interference at the satellite broadcast receiver resulting from the less directive antenna. A novel satellite reception front-end antenna based on a multiple

Decision-directed interference cancellation applied to satellite broadcast reception

2005

This paper investigates the usage of established interference cancellation techniques applied to the simultaneous reception of geostationary satellite broadcast signals from two or more satellites. In particular the reduction of interference from adjacent satellites is of interest, which would allow a reduction of the antenna size and the requirements on the directivity of the installation. The rejection of unwanted adjacent satellite interferers can imply a large equivalent parabolic reflector size to achieve the required spatial separation of the signals. The usage of small and cheap reception antennas at the end-user premises can be facilitated by the reduction of the requirements on the antenna characteristics in terms of adjacent satellite interference rejection, in particular for the joint reception of signals from two or more simultaneous geostationary orbital locations.

Applicability of interference processing to DTH reception

2006

Today fixed satellite broadcast reception has to compete efficiently with other means of broadcast content delivery to end-users. The ease of reception is essential to maintain a high penetration rate under more competitive conditions. The introduction of DVB-S2 increases efficiency and allows for a higher throughput or a reduction of the reception equipment requirements. This means that a robust broadcast reception is conceivable with a reduced direct-to-home (DTH) antenna size. The current interference situation at common geostationary broadcast positions dictates the spatial discrimination requirements of common direct-to-home (DTH) reception antennas. A more robust coding rate or a relaxation of the frequency coordination constraints would obviously relax the requirements on the reception front-end but only at the expense of a reduced aggregate efficiency. The use of known interference processing schemes for DTH reception has been investigated under dual reception path scenarios, see . The present work extends the concept by introducing linear pre-processing (LPP) to combine coherent reception paths. These mechanisms will only be practical if the transmitted broadcast signals are compliant with established standards (ie. DVB-S [5] or DVB-S2 [4]). The maximization of the efficiency is a main objective under given reception environments. We show how multiuser detection techniques can increase efficiency and allow reduced antenna size under realistic conditions.

Space-time MMSE receivers for non-ideal multi-satellite channels

Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738), 2004

This paper deals with the development of two new schemes of space-time MMSE receivers implemented for the forward link of a WCDMA multi-satellite system and their performance evaluation under non-ideal conditions. A comparison with other two space-time MMSE detectors already presented in the literature is also introduced. In this work the so called space-time transmit diversity technique (STTD) has been coupled with the minimum mean square error (MMSE) interference suppression technique. The idea has come from the realization that the diversity gain is limited by a medium-high level of multiple access interference ([14], [2]). As known, the classical Alamouti STTD ([3]) technique needs symbols synchronicity at the receiver. Firstly, in this paper we drop this need, extending the STTD technique to the asynchronous signals case. The proposed schemes can be distinguished by the order in which the spacetime processing and the MMSE interference suppression are performed. We named ST-MMSE Pre STTD if the MMSE filtering is performed before the space-time combining and ST-MMSE Post STTD if the interference suppression and the space-time combining are jointly processed. The STTD technique is based on the knowledge of the channel coefficients at the receiver. This paper aims also to answer to the following question: what happens when the channel coefficients are not perfectly estimated? Normally, no matter as the estimator is accurate, errors in the channel complex coefficients evaluation occur and the ST-MMSE receivers performance could be strongly degraded. A realistic multi-satellite WCDMA environment has been simulated in order to compare the proposed detectors. Bit error rates have been calculated by mean of Montecarlo simulations assuming a time-varying satellite channel model. The results show that the proposed Post-combining scheme gives the best results, when the estimation errors are not present, but it is more sensitive to the estimation errors than other receivers in the pedestrian channel. Anyway, the receivers, here proposed, still outperform the other schemes presented in literature in the vehicular channel, i.e., when the receiver has a high mobility, although a 30 o of channel phase coefficients estimation error is present. This work has to be intended as an extension of the previous works in [19] and [20].

Interference analysis in satellite cellular systems

[1992 Proceedings] The Third IEEE International Symposium on Personal, Indoor and Mobile Radio Communications

In next generation satellite mobile systems very high spectrum efficiency will be a primary objective. High spectrum efficiency is often related to a significant amount of eo-channel andlor adjacent channel interference. Therefore, system design should in general include consideration of both interference and noise effects. Interference evaluation in a mobile salellite cellular system is different from the case of a terrestrial system due to the presence of the on-board antenna which acts as a spatial filter. The paper addresses the modeling of interference in single and multi-satellite cellular system and provides some results of the analysis.

Space-Time MMSE Reception in Multi-Satellite UMTS

GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489)

This paper deals with the comparison among two schemes of space-time MMSE reception implemented for the forward link of a WCDMA multi-satellite UMTS environment. The so called space-time transmit diversity technique (STTD) has been coupled with the minimum mean square error (MMSE) interference suppression technique. The idea has come from the realization that the diversity gain is limited by a medium-high level of multiple access interference ([11]. The proposed schemes can be distinguished by the order in which the space-time processing and the MMSE interference suppression are performed. We named ST-MMSE Pre STTD Combining if the MMSE filtering is performed before the space-time combining and ST-MMSE Post STTD Combining if the interference suppression and the spacetime combining are jointly processed. A realistic multi-satellite UMTS environment has been simulated in order to compare the proposed detectors. Bit error rates have been calculated by mean of Monte Carlo simulations assuming a time-varying satellite channel model. Simulations show that the Post-combining scheme gives the best results, but it implies more complexity to the mobile terminal. Anyway, both the proposed ST-MMSE schemes yield significantly better performance than the standard STTD receiver or the conventional RAKE receiver.

MMSE Performance Analysis of Generalized Multibeam Satellite Channels

IEEE Communications Letters, 2000

Aggressive frequency reuse in the return link (RL) of multibeam satellite communications (SatComs) is crucial towards the implementation of next generation, interactive satellite services. In this direction, multiuser detection has shown great potential in mitigating the increased intrasystem interferences, induced by a tight spectrum reuse. Herein we present an analytic framework to describe the linear Minimum Mean Square Error (MMSE) performance of multiuser channels that exhibit full receive correlation: an inherent attribute of the RL of multibeam SatComs. Analytic, tight approximations on the MMSE performance are proposed for cases where closed form solutions are not available in the existing literature. The proposed framework is generic, thus providing a generalized solution straightforwardly extendable to various fading models over channels that exhibit full receive correlation. Simulation results are provided to show the tightness of the proposed approximation with respect to the available transmit power.

Iterative interference cancellation and channel estimation in multibeam satellite systems

International Journal of Satellite Communications and Networking, 2007

This paper deals with the use of non-linear multiuser detection techniques to mitigate co-channel interference on the reverse link of multibeam satellite systems. These techniques allow more capacity efficient frequency reuse strategies than classical ones, as they make possible to cope with lower C/I. The considered system takes as a starting point the DVB-RCS standard, with the use of convolutional coding, and the use of the Ka-band.We propose different iterative interference cancellation schemes, which operate at the beamformer outputs, and which use information from decoders. The proposed receivers assume an initial single-user synchronization step: frame synchronization and timing recovery, and then perform channel estimation: beamformer coefficients; signal carrier phases and signal amplitudes.In a first step, these receivers are evaluated by simulation in terms of bit error rate and of channel estimation error on two interference configurations. For one of these receivers, sensitivity to imperfect timing recovery and to low-frequency offsets from user terminals is evaluated.In a second step, since the receiver performances highly depend on the interference configuration, we propose an approach to evaluate performances on a multibeam coverage (by taking into account the variability of interference configurations on the coverage). This method is used to compare different receivers on an example based on a coverage designed on a digital focal array feed reflector antenna. Copyright © 2007 John Wiley & Sons, Ltd.

Frequency Estimation in Iterative Interference Cancellation Applied to Multibeam Satellite Systems

Eurasip Journal on Wireless Communications and Networking, 2007

This paper deals with interference cancellation techniques to mitigate cochannel interference on the reverse link of multibeam satellite communication systems. The considered system takes as a starting point the DVB-RCS standard with the use of convolutional coding. The considered algorithm consists of an iterative parallel interference cancellation scheme which includes estimation of beamforming coefficients. This algorithm is first derived in the case of a symbol asynchronous channel with time-invariant carrier phases. The aim of this article is then to study possible extensions of this algorithm to the case of frequency offsets affecting user terminals. The two main approaches evaluated and discussed here are based on (1) the use of block processing for estimation of beamforming coefficients in order to follow carrier phase variations and (2) the use of single-user frequency offset estimations.