Ari Pouttu

Method selection diversity approach to interference suppression

The interference suppression problem has introduced a large variety of suppression algorithms. A large majority of cases, the proposed algorithms are targeted against a specific type of interference and fail to suppress other types of interfering signals. We propose a SINR estimator based method to select between several relatively simple interference suppression methods to overcome this problem. We combine three suppression algorithms, namely CME-notch-, RLS- and polar-suppression filters. The approach is to use a DPSK-modulated hybrid direct sequence (DS) frequency hopping (FH) system model, but the suppression method is also applicable to pure DS-systems or MC-CDMA-systems. The performance results show that this approach has the capability of operating under a wide range of interference parameters.

Adaptive transform domain interference suppression in a hybrid DS/FH-system

We study the performance of a hybrid direct sequence frequency hopping (DS/FH) system with interference suppression in an environment where narrowband (relative to the DS spreading code bandwidth) interference perturbs the signal. In suppressing the narrowband interference, a transform domain approach has been chosen, i.e. the interference suppression takes place, e.g. in the frequency domain. This approach is more practical since the duration of a frequency hop is prohibitive to the use of time domain adaptive filtering. The aim of this paper is to study the relative performance of four different adaptive rules used in determining and suppressing the interfered frequencies in the frequency domain. The interference environment changes from frequency hop to hop but during each hop the interference is considered time-invariant. To avoid spectral leaking of the interfering power, windowing can be performed prior to transformation. The transformations are accomplished with the FFT and the inverse FFT algorithms. After the interference suppression the signal is transformed back to the time domain to be fed to the DS-code matched filter. The criterion used for the performance comparisons is the bit error probability as a function of E/sub 1//N/sub 0/ and S/J. The numerical results were obtained by Monte Carlo simulations.

Differentially coherent code acquisition in Doppler

This paper considers the use of differentially coherent (DC) matched filter (MF) code acquisition in a direct-sequence (DS) spread spectrum system. Both a simplified analysis and simulation results are presented in an AWGN channel. The performance of the structure is compared to a conventional noncoherent (NC) MF acquisition. The performance measure is mainly the mean acquisition time, T/sub MA/, but also receiver operating characteristics (ROC) curves are given. The results indicate that the differentially coherent method is robust by allowing the use of post detection integration also in quite severe Doppler shifts.

Differentially coherent code acquisition in jamming and data modulation

This paper considers the use of differentially coherent (DC) matched filter (MF) code acquisition in a direct-sequence (DS) spread-spectrum system. Simulation results in tone jamming and with data modulation are presented. The performance of the structure is compared to conventional noncoherent (NC) MF acquisition. The performance measure is the mean acquisition time, T/sub MA/. The results indicate that the differentially coherent method is a robust method by allowing the use of post detection integration also in case of jamming and data modulation, in addition to quite severe Doppler shifts.

Synchronization of FH/DS Signal with Interference Suppression Diversity

The interference suppression problem has introduced a large variety of suppression algorithms. A large majority of the proposed algorithms is targeted against a specific type of interference signal and fail to suppress other types of interfering signals. In this paper we examine a earlier proposed SINR estimator based method to select between several relatively simple interference suppression methods. In this paper we examine the applicability and performance of the approach in timing synchronization. In this study the interference suppression selection is made between pure matched filter, CME-notch, and Polar-suppression filters. The approach in the paper is to use a DPSK-modulated hybrid direct sequence (DS) frequency hopping (FH) system model but the suppression method is also applicable to pure DS-system or MC/CDMA-system. The performance results show that this approach has the capability to operate under wide range of interference parameters

Frequency hopping multicarrier mMCSK modulation

Multicarrier modulation, and especially OFDM, has gained a wide interest due to the deployment of digital video broadcasting (DVB) and digital audio broadcasting (DAB). The main driver in commercial applications is the availability of high data rates with reasonable signal processing requirements. In some systems, pure OFDM signals, however, do not provide enough resistance to interference and hence multicarrier modulation has often been considered. We propose mMCSK signaling in conjunction with multicarrier modulation. The main point is to preserve a high data rate capability while enhancing interference resistance. We present the bit error rate analysis of the proposed scheme in an AWGN channel and consider the method in conjunction with a frequency hopping system.

5G CHAMPION - Rolling out 5G in 2018

The 5G CHAMPION Consortium will provide the first fully integrated and operational 5G prototype in 2018 - this effort is a major leap ahead compared to existing punctual technology trials, such as, e.g., Proof-of-Concept platforms focusing on mmWave communication in specific bands, etc. This paper describes the overall set-up including a synergetic combination of technologies such as beamforming based mmWave & Satellite service provisioning, virtualized infrastructure, software reconfiguration across the entire stack, accurate positioning and high-speed solutions. The key enablers are described in detail and related efforts in standards and regulation organizations are discussed.

New tactical radio systems in Finland

This article describes the developments in the field of emerging new military radio systems to be deployed in Finland, Finnish software radio programme is the tool to deploy these new systems. The demonstrator platform, that is being build, is a software defined radio wherein the developed wideband applications can be demonstrated. The systems that will be deployed on the demonstrator platform - tactical radio communication system (TRCS) and national tactical positioning system (NTPS) - are introduced in this paper. Brief introduction of the adaptive antenna system to be applied in the demonstrator is also given

Effects of Rayleigh fading to method-selection in interference suppression

The interference suppression problem has introduced a large variety of suppression algorithms. A large majority of the proposed algorithms is targeted against a specific type of interference signal and fail to suppress other types of interfering signals. In this paper we examine a earlier proposed SINR estimator based method to select between several relatively simple interference suppression methods in Rayleigh fading channel. In this study the interference suppression selection is made between CME-notch-, RLSand polar-suppression filters. The approach in the paper is to use a DPSK-modulated hybrid direct sequence (DS) frequency hopping (FH) system model but the suppression method is also applicable to pure DS-system or MC/CDMA-system. The performance results show that this approach has the capability to operate under wide range of interference parameters and Rayleigh fading

Differentially coherent code acquisition in wideband jamming

This paper considers the use of differentially coherent (DC) matched filter (MF) code acquisition in a direct-sequence (DS) spread-spectrum system. Simulation results in wideband jamming are presented. The performance of structure is compared to conventional noncoherent (NC) MF acquisition. The performance measure is the mean acquisition time, T/sub MA/. The results indicate that the differentially coherent method is a robust method by allowing also wideband jamming in quite severe Doppler shifts in addition to previously investigated narrowband interference and data modulation conditions.