Aarne Mämmelä | VTT Techn. Res. centre of Finland (original) (raw)
Papers by Aarne Mämmelä
2022 IEEE Future Networks World Forum (FNWF)
12th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications. PIMRC 2001. Proceedings (Cat. No.01TH8598)
A6sinrci-A new adaptive reduced<omplexity MLSE receiver based on per-sdvor processing (PSP-MLS... more A6sinrci-A new adaptive reduced<omplexity MLSE receiver based on per-sdvor processing (PSP-MLSE) and a decision feedback equalizer @FE) for GSWDGE system with BPSK modulation is proposed in this paper. The initial channel im-pulse response (CIR) is estimated by the ...
IEEE International Conference on Communications, 2005. ICC 2005. 2005
ABSTRACT
IEEE VTS 53rd Vehicular Technology Conference, Spring 2001. Proceedings (Cat. No.01CH37202), 2001
ABSTRACT
IEEE Second International Symposium on Spread Spectrum Techniques and Applications
Fixed-point two's-complement arithmetic was simulated in the LMS and the VS algorithms. The simul... more Fixed-point two's-complement arithmetic was simulated in the LMS and the VS algorithms. The simulation method is first briefly described. The algorithms were used as interference suppression algorithms in a DS spread-spectrum system. The simulated performance results were compared to the theoretical results. It was found that the theoretical results are optimistic in the present application where the covariance matrix of the input signal is often ill conditioned. The VS algorithm is more robust than the LMS algorithm against the finite word-length effects since the former has the freedom to select the best possible step size at different word lengths.
8th European Conference on Electrotechnics, Conference Proceedings on Area Communication
The performance of the optimal and adaptive interference suppression filters in pseudonoise sprea... more The performance of the optimal and adaptive interference suppression filters in pseudonoise spread spectrum systems has been determined by simulation. The performance index is the factor which represents the improvement in the signal-to-noise ratio due to the use of the interference suppression filter. The simulations include the linear M-step prediction and interpolation filters and some of the best-known iterative and
2011 IEEE 22nd International Symposium on Personal, Indoor and Mobile Radio Communications, 2011
ABSTRACT This paper proposes a novel adaptive power control scheme to be used in nonergodic fadin... more ABSTRACT This paper proposes a novel adaptive power control scheme to be used in nonergodic fading channels. We use the decision-theoretic criterion known as Telser's safety-first criterion and variational calculus to construct the adaptive power control scheme that maximizes the average transmission rate subject to the average transmission power constraint and outage probability constraint for a given target transmission rate. We recognize that for a given power budget only some combinations of outage probability and target transmission rate are feasible and derive the boundary of the feasible set of those parameters. Numerical results suggest that some feasible combinations of the constraints are inferior to the other ones. We present a practical way to properly select the superior set of constraints. The proposed scheme is the extension of the traditional scheme which aims only at minimizing the outage probability for a given target transmission rate and average transmission power.
2010 IEEE 71st Vehicular Technology Conference, 2010
ABSTRACT Proceedings of the 71st IEEE Vehicular Technology Conference, 1 - 5 In this paper we pre... more ABSTRACT Proceedings of the 71st IEEE Vehicular Technology Conference, 1 - 5 In this paper we present an adaptive transmission scheme that leads to a surprising situation in analysis of a mathematical model of wireless communications. Namely, the average received energy tends to infinity despite the fact that the average transmitted energy and the representative energy gain of the channel are finite. Yet, it is reasonable to postulate that such a scheme should not be used in any practical wireless system. This anomaly is commonly referred to as St. Petersburg paradox. We discuss possible reasons for the St. Petersburg paradox to occur in analysis of wireless systems and how it can be resolved using suitable performance metrics and fading models. For example, the paradox is resolved by optimizing some performance metric which is either bounded or concave function of the received signal-to-noise ratio. The analysis of St. Petersburg paradox brings new intuition to the normalization of fading channels and optimization of wireless systems. IEEE Vehicular Technology Conference. VTC 2010-Spring, Taipei, 16 - 19 May 2010
2012 18th Asia-Pacific Conference on Communications (APCC), 2012
ABSTRACT A new coded modulation with a phase shift is proposed. The parity bits decide how to shi... more ABSTRACT A new coded modulation with a phase shift is proposed. The parity bits decide how to shift the signal constellation point of information bits in the transmitter. In the receiver, the phase shift detector estimates how much the constellation points are shifted and then recovers the parity bit. Based on the recovered parity bit, soft input soft output decoding is carried out. The asymptotic coding gains of the proposed scheme using the (9,8) single parity check code are 3 dB and 0.7 dB when compared with the uncoded BPSK and QPSK, respectively. It is shown with simulations that the proposed scheme using the (9,8) single parity check code has at bit error rate 10-5 about 2 dB gain compared with uncoded transmission and 0.5 dB gain compared with the (9,8) conventional single parity check code. In addition, concatenated codes are designed using the proposed coded modulation as the inner code. The concatenated code using the (255,247) Reed-Solomon code as the outer code and the proposed coded modulation as the inner code is designed as an example. It is shown that it has about 2 dB gain at bit error rate 10-5 when compared with the conventional (255,247) Reed-Solomon code.
VTC Spring 2008 - IEEE Vehicular Technology Conference, 2008
ABSTRACT
ICCT'98. 1998 International Conference on Communication Technology. Proceedings (IEEE Cat. No.98EX243)
Intemational Conference on Communication Technology ICCT'98 October 22-24, 1998 Beijing, Chi... more Intemational Conference on Communication Technology ICCT'98 October 22-24, 1998 Beijing, China ... Tap Selection Scheme in a W-CDMA System ... Li Zhenhong, Aarne Mammela VTT Electronics, PO Box 1 100, FIN-9057 1 , Oulu, Finland Tel.: +358 8 551 2111, fax: ...
IEEE Second International Symposium on Spread Spectrum Techniques and Applications
the transmitted spreading waveform and Tb is the bit interval. The length of p(t) is Tb. (p(t) is... more the transmitted spreading waveform and Tb is the bit interval. The length of p(t) is Tb. (p(t) is zero outside the interval I t 4 Tb). The effect of a non-ideal autocorrelation function of a spreading code upon a RAKE matched filter is studied in a fixed two-path channel. An autocorrelation function with nonzero sidelobes causes interpath and intersymbol interference in a multiDath channel. In addition. the sidelobes cause bias Channel Model errors & the estimate of the channel impulse response. Bit error probability is used to measure the effect of these factors. The transmitted DS-spread spectrum signal propagated through the discrete two-path channel and white Gaussian noise was added to the received signal. The received signal r(t) is
Proceedings of IEEE 3rd International Symposium on Spread Spectrum Techniques and Applications (ISSSTA'94)
ABSTRACT
2005 IEEE 61st Vehicular Technology Conference
We propose a method to simulate impairments caused by the nonideal analog parts of the transmitte... more We propose a method to simulate impairments caused by the nonideal analog parts of the transmitter-receiver. They include for example a high-power amplifier (HPA), mixers, and oscillators. The major advantage in our approach is that the model parameters are adjustable and the system works in real time in the digital domain. Conventional methods have either not been real time, or
2012 IEEE 23rd International Symposium on Personal, Indoor and Mobile Radio Communications - (PIMRC), 2012
ABSTRACT In this paper, we consider multiantenna energy detection (ED) of nonnegative pulse-ampli... more ABSTRACT In this paper, we consider multiantenna energy detection (ED) of nonnegative pulse-amplitude-modulated (PAM) symbols suitable for low-power and low-complexity short-range communication radios using a very wide bandwidth or high centre frequency. We present a general condition which leads to the cancellation of the spatial cross products between the distinct PAM space-time coded signals at the output of an ED-based multiantenna diversity decoder. Moreover, it is shown that our existing analysis approach for single antenna ED-PAM systems in very wideband lognormal multipath fading channels can be conveniently extended for fast evaluation of spatial diversity gain and correlation effects between antenna elements in multiantenna ED-PAM systems. The error probability performance is illustrated for the selected system parameters by using the proposed analysis tool. The accuracy of the analysis approach is demonstrated with appropriate simulations.
IEEE International Conference on Communications, 2003. ICC '03.
AbstractAn adaptive reduced-state sequence estimation (RSSE) receiver based on per-survivor proc... more AbstractAn adaptive reduced-state sequence estimation (RSSE) receiver based on per-survivor processing (PSP) in conjunction with a local decision feedback equalizer (DFE) for the EDGE system with 8PSK modulation is proposed in this paper. A pre-filter prior to the ...
2007 IEEE 65th Vehicular Technology Conference - VTC2007-Spring, 2007
... Antti Anttonen, Sami Siltala, and Aarne Mämmelä VTT Technical Research Centre of Finland Kait... more ... Antti Anttonen, Sami Siltala, and Aarne Mämmelä VTT Technical Research Centre of Finland Kaitoväylä 1, PO Box 1100, FI-90571 Oulu ... and PHO, and the results are compared to the performance of ideal frequency-switching and the corresponding analytical Cramer-Rao bound ...
2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 2013
ABSTRACT In this paper, we propose a modified unitary multiple signal classification (MUSIC) algo... more ABSTRACT In this paper, we propose a modified unitary multiple signal classification (MUSIC) algorithm for a two-port composite right/left handed (CRLH) leaky-wave antenna (LWA). The algorithm requires only real-valued operations to estimate direction of arrival (DoA) of the received signals, which will simplify future hardware implementation. The CRLH LWA consists of a cascade of metamaterial unit cells, periodically modulated using varactor diodes. By changing the voltages across series and shunt varactors, the antenna is able to uniformly steer its radiation pattern. The proposed modified unitary MUSIC algorithm uses both antennas' input ports to estimate the DoA. Existing MUSIC implementations requires eigenvalue decomposition in the complex-valued signal subspace, which results in highly complex hardware implementation. The computational complexity can be reduced using our proposed modified unitary MUSIC algorithm since it transforms the complex-valued covariance matrix of the received signals to a real-valued matrix using unitary transformations. The performance of the algorithm is experimentally demonstrated by using a CRLH LWA within an anechoic chamber facility and the estimated DoA results are in good agreement with the predicted angles.
GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489)
Accurate channel estimates are needed in space-time coded OFDM systems for decoding purposes. In ... more Accurate channel estimates are needed in space-time coded OFDM systems for decoding purposes. In this paper, a novel channel tracking algorithm based on space-time coded training and information symbols is presented. The algorithm takes advantage of the orthogonality properties of the space-time block codes and it is therefore capable of providing channel estimates without performance degradation due to estimation errors
2022 IEEE Future Networks World Forum (FNWF)
12th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications. PIMRC 2001. Proceedings (Cat. No.01TH8598)
A6sinrci-A new adaptive reduced<omplexity MLSE receiver based on per-sdvor processing (PSP-MLS... more A6sinrci-A new adaptive reduced<omplexity MLSE receiver based on per-sdvor processing (PSP-MLSE) and a decision feedback equalizer @FE) for GSWDGE system with BPSK modulation is proposed in this paper. The initial channel im-pulse response (CIR) is estimated by the ...
IEEE International Conference on Communications, 2005. ICC 2005. 2005
ABSTRACT
IEEE VTS 53rd Vehicular Technology Conference, Spring 2001. Proceedings (Cat. No.01CH37202), 2001
ABSTRACT
IEEE Second International Symposium on Spread Spectrum Techniques and Applications
Fixed-point two's-complement arithmetic was simulated in the LMS and the VS algorithms. The simul... more Fixed-point two's-complement arithmetic was simulated in the LMS and the VS algorithms. The simulation method is first briefly described. The algorithms were used as interference suppression algorithms in a DS spread-spectrum system. The simulated performance results were compared to the theoretical results. It was found that the theoretical results are optimistic in the present application where the covariance matrix of the input signal is often ill conditioned. The VS algorithm is more robust than the LMS algorithm against the finite word-length effects since the former has the freedom to select the best possible step size at different word lengths.
8th European Conference on Electrotechnics, Conference Proceedings on Area Communication
The performance of the optimal and adaptive interference suppression filters in pseudonoise sprea... more The performance of the optimal and adaptive interference suppression filters in pseudonoise spread spectrum systems has been determined by simulation. The performance index is the factor which represents the improvement in the signal-to-noise ratio due to the use of the interference suppression filter. The simulations include the linear M-step prediction and interpolation filters and some of the best-known iterative and
2011 IEEE 22nd International Symposium on Personal, Indoor and Mobile Radio Communications, 2011
ABSTRACT This paper proposes a novel adaptive power control scheme to be used in nonergodic fadin... more ABSTRACT This paper proposes a novel adaptive power control scheme to be used in nonergodic fading channels. We use the decision-theoretic criterion known as Telser's safety-first criterion and variational calculus to construct the adaptive power control scheme that maximizes the average transmission rate subject to the average transmission power constraint and outage probability constraint for a given target transmission rate. We recognize that for a given power budget only some combinations of outage probability and target transmission rate are feasible and derive the boundary of the feasible set of those parameters. Numerical results suggest that some feasible combinations of the constraints are inferior to the other ones. We present a practical way to properly select the superior set of constraints. The proposed scheme is the extension of the traditional scheme which aims only at minimizing the outage probability for a given target transmission rate and average transmission power.
2010 IEEE 71st Vehicular Technology Conference, 2010
ABSTRACT Proceedings of the 71st IEEE Vehicular Technology Conference, 1 - 5 In this paper we pre... more ABSTRACT Proceedings of the 71st IEEE Vehicular Technology Conference, 1 - 5 In this paper we present an adaptive transmission scheme that leads to a surprising situation in analysis of a mathematical model of wireless communications. Namely, the average received energy tends to infinity despite the fact that the average transmitted energy and the representative energy gain of the channel are finite. Yet, it is reasonable to postulate that such a scheme should not be used in any practical wireless system. This anomaly is commonly referred to as St. Petersburg paradox. We discuss possible reasons for the St. Petersburg paradox to occur in analysis of wireless systems and how it can be resolved using suitable performance metrics and fading models. For example, the paradox is resolved by optimizing some performance metric which is either bounded or concave function of the received signal-to-noise ratio. The analysis of St. Petersburg paradox brings new intuition to the normalization of fading channels and optimization of wireless systems. IEEE Vehicular Technology Conference. VTC 2010-Spring, Taipei, 16 - 19 May 2010
2012 18th Asia-Pacific Conference on Communications (APCC), 2012
ABSTRACT A new coded modulation with a phase shift is proposed. The parity bits decide how to shi... more ABSTRACT A new coded modulation with a phase shift is proposed. The parity bits decide how to shift the signal constellation point of information bits in the transmitter. In the receiver, the phase shift detector estimates how much the constellation points are shifted and then recovers the parity bit. Based on the recovered parity bit, soft input soft output decoding is carried out. The asymptotic coding gains of the proposed scheme using the (9,8) single parity check code are 3 dB and 0.7 dB when compared with the uncoded BPSK and QPSK, respectively. It is shown with simulations that the proposed scheme using the (9,8) single parity check code has at bit error rate 10-5 about 2 dB gain compared with uncoded transmission and 0.5 dB gain compared with the (9,8) conventional single parity check code. In addition, concatenated codes are designed using the proposed coded modulation as the inner code. The concatenated code using the (255,247) Reed-Solomon code as the outer code and the proposed coded modulation as the inner code is designed as an example. It is shown that it has about 2 dB gain at bit error rate 10-5 when compared with the conventional (255,247) Reed-Solomon code.
VTC Spring 2008 - IEEE Vehicular Technology Conference, 2008
ABSTRACT
ICCT'98. 1998 International Conference on Communication Technology. Proceedings (IEEE Cat. No.98EX243)
Intemational Conference on Communication Technology ICCT'98 October 22-24, 1998 Beijing, Chi... more Intemational Conference on Communication Technology ICCT'98 October 22-24, 1998 Beijing, China ... Tap Selection Scheme in a W-CDMA System ... Li Zhenhong, Aarne Mammela VTT Electronics, PO Box 1 100, FIN-9057 1 , Oulu, Finland Tel.: +358 8 551 2111, fax: ...
IEEE Second International Symposium on Spread Spectrum Techniques and Applications
the transmitted spreading waveform and Tb is the bit interval. The length of p(t) is Tb. (p(t) is... more the transmitted spreading waveform and Tb is the bit interval. The length of p(t) is Tb. (p(t) is zero outside the interval I t 4 Tb). The effect of a non-ideal autocorrelation function of a spreading code upon a RAKE matched filter is studied in a fixed two-path channel. An autocorrelation function with nonzero sidelobes causes interpath and intersymbol interference in a multiDath channel. In addition. the sidelobes cause bias Channel Model errors & the estimate of the channel impulse response. Bit error probability is used to measure the effect of these factors. The transmitted DS-spread spectrum signal propagated through the discrete two-path channel and white Gaussian noise was added to the received signal. The received signal r(t) is
Proceedings of IEEE 3rd International Symposium on Spread Spectrum Techniques and Applications (ISSSTA'94)
ABSTRACT
2005 IEEE 61st Vehicular Technology Conference
We propose a method to simulate impairments caused by the nonideal analog parts of the transmitte... more We propose a method to simulate impairments caused by the nonideal analog parts of the transmitter-receiver. They include for example a high-power amplifier (HPA), mixers, and oscillators. The major advantage in our approach is that the model parameters are adjustable and the system works in real time in the digital domain. Conventional methods have either not been real time, or
2012 IEEE 23rd International Symposium on Personal, Indoor and Mobile Radio Communications - (PIMRC), 2012
ABSTRACT In this paper, we consider multiantenna energy detection (ED) of nonnegative pulse-ampli... more ABSTRACT In this paper, we consider multiantenna energy detection (ED) of nonnegative pulse-amplitude-modulated (PAM) symbols suitable for low-power and low-complexity short-range communication radios using a very wide bandwidth or high centre frequency. We present a general condition which leads to the cancellation of the spatial cross products between the distinct PAM space-time coded signals at the output of an ED-based multiantenna diversity decoder. Moreover, it is shown that our existing analysis approach for single antenna ED-PAM systems in very wideband lognormal multipath fading channels can be conveniently extended for fast evaluation of spatial diversity gain and correlation effects between antenna elements in multiantenna ED-PAM systems. The error probability performance is illustrated for the selected system parameters by using the proposed analysis tool. The accuracy of the analysis approach is demonstrated with appropriate simulations.
IEEE International Conference on Communications, 2003. ICC '03.
AbstractAn adaptive reduced-state sequence estimation (RSSE) receiver based on per-survivor proc... more AbstractAn adaptive reduced-state sequence estimation (RSSE) receiver based on per-survivor processing (PSP) in conjunction with a local decision feedback equalizer (DFE) for the EDGE system with 8PSK modulation is proposed in this paper. A pre-filter prior to the ...
2007 IEEE 65th Vehicular Technology Conference - VTC2007-Spring, 2007
... Antti Anttonen, Sami Siltala, and Aarne Mämmelä VTT Technical Research Centre of Finland Kait... more ... Antti Anttonen, Sami Siltala, and Aarne Mämmelä VTT Technical Research Centre of Finland Kaitoväylä 1, PO Box 1100, FI-90571 Oulu ... and PHO, and the results are compared to the performance of ideal frequency-switching and the corresponding analytical Cramer-Rao bound ...
2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 2013
ABSTRACT In this paper, we propose a modified unitary multiple signal classification (MUSIC) algo... more ABSTRACT In this paper, we propose a modified unitary multiple signal classification (MUSIC) algorithm for a two-port composite right/left handed (CRLH) leaky-wave antenna (LWA). The algorithm requires only real-valued operations to estimate direction of arrival (DoA) of the received signals, which will simplify future hardware implementation. The CRLH LWA consists of a cascade of metamaterial unit cells, periodically modulated using varactor diodes. By changing the voltages across series and shunt varactors, the antenna is able to uniformly steer its radiation pattern. The proposed modified unitary MUSIC algorithm uses both antennas' input ports to estimate the DoA. Existing MUSIC implementations requires eigenvalue decomposition in the complex-valued signal subspace, which results in highly complex hardware implementation. The computational complexity can be reduced using our proposed modified unitary MUSIC algorithm since it transforms the complex-valued covariance matrix of the received signals to a real-valued matrix using unitary transformations. The performance of the algorithm is experimentally demonstrated by using a CRLH LWA within an anechoic chamber facility and the estimated DoA results are in good agreement with the predicted angles.
GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489)
Accurate channel estimates are needed in space-time coded OFDM systems for decoding purposes. In ... more Accurate channel estimates are needed in space-time coded OFDM systems for decoding purposes. In this paper, a novel channel tracking algorithm based on space-time coded training and information symbols is presented. The algorithm takes advantage of the orthogonality properties of the space-time block codes and it is therefore capable of providing channel estimates without performance degradation due to estimation errors