Markku Renfors

• Tampere University

This document discloses a solution for modulating and demodulating signals transferred over a communication channel. According to an aspect, a method comprises: storing a database for mapping rules for mapping a block of N bits into M modulation symbol phase transitions, wherein a phase transition between consecutive modulation symbols is limited t...

Orthogonal frequency-division multiplexing (OFDM) has been selected as a baseline waveform for long-term evolution (LTE) and fifth-generation new radio (5G NR). Fast-convolution (FC)-based frequency-domain signal processing has been recently considered as an effective tool for transmitter and receiver side subband filtering of OFDM-based waveforms....

Orthogonal frequency-division multiplexing (OFDM) has been selected as a baseline waveform for long-term evolution (LTE) and fifth-generation new radio (5G NR). Fast-convolution (FC)-based frequency-domain signal processing has been considered recently as an effective tool for spectrum enhancement of OFDM-based waveforms. FC-based filtering approxi...

根据一方面，提供了一种波形处理设备(600)。所述波形处理设备(600)包括用于执行以下的部件。一经接收到一个或多个输入信号(601、611、621)，波形处理设备(600)将一个或多个输入信号(601、611、621)中的每个输入信号分段为并行信号块的特定于子带的集合，一个或多个输入信号中的每个输入信号对应于不同的子带。然后，波形处理设备(600)通过按如下顺序应用至少第一时间窗函数(603、613、623)、变换平面窗函数(604、614、624)和第二时间窗函数(608)，来对每个特定于子带的集合进行滤波。最后，波形处理设备(600)将经滤波的信号级联成输出信号(610)

In this paper, a novel waveform with low peak-to-average power ratio (PAPR) and high robustness against phase noise (PN) is presented. It follows the discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) signal model. This scheme, called 3MSK, is inspired by continuous-phase frequency shift keying (CPFSK), but it...

A novel OFDM-based waveform with low peak-to-average power ratio (PAPR) and high robustness against phase noise (PN) is presented. It follows the discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) signal model. 3MSK, is inspired by continuous-phase frequency shift keying (FSK), but it uses three frequencies in...

A novel Flip-filter bank multicarrier (Flip-FBMC) based transmultiplexer (TMUX) with offset quadrature amplitude modulation is proposed to enhance the Flip-OFDM performance. Moreover, the possibility to reduce the TMUX response (latency) and increase the gain in the spectral efficiency have been investigated for the first time through a tail shorte...

Orthogonal frequency-division multiplexing (OFDM) has been selected as the basis for the fifth-generation new radio (5G NR) waveform developments. However, effective signal processing tools are needed for enhancing the OFDM spectrum in various advanced transmission scenarios. In earlier work, we have shown that fast-convolution (FC) processing is a...

Cognitive radio (CR) technology with dynamic spectrum management capabilities is widely advocated for utilizing effectively the unused spectrum resources. The main idea behind CR technology is to trigger secondary communications to utilize the unused spectral resources. However, CR technology heavily relies on spectrum sensing techniques which are...

The physical-layer radio access of 5G New Radio (NR) and other modern wireless networks builds on the cyclic prefix (CP) orthogonal frequency-division multiplexing (OFDM), known to suffer from the high peak-to-average power ratio (PAPR) challenge. In this paper, novel PAPR reduction methods are developed, referred to as the iterative clipping and w...

In this article, the 5G New Radio (NR) physical layer evolution to support beyond 52.6 GHz communications is addressed. The performance of both OFDM based and DFT-s-OFDM based networks are evaluated with special emphasis on the phase noise (PN) induced distortion. It is shown that DFT-s-OFDM is more robust against PN under 5G NR Release 15 assumpti...

In this paper, we investigate multi-antenna interference rejection combing (IRC)-based black-space cognitive radio (BS-CR) operation in time-varying channels. The idea of BS-CR is to transmit secondary user (SU) signal in the same frequency band with the primary user (PU) such that SU’s power spectral density is clearly below that of the PU, and no...

Orthogonal frequency-division multiplexing (OFDM) has been selected as the basis for the fifth-generation new radio (5G-NR) waveform developments. However, effective signal processing tools are needed for enhancing the OFDM spectrum in various advanced transmission scenarios. In earlier work, we have shown that fast-convolution (FC) processing is a...

This paper proposes a cyclic prefix (CP) free spectral efficiency frequency division multiplexing (SEFDM) wireless signal transmission and reception method based on alignment signal (AS). The method needs the cooperation of both the transmission and reception sides. At the transmitter, time-domain AS is designed to prevent inter-symbol interference...

In wireless communications, higher transmission power enables higher coverage or higher data rate. However, due to hardware limitations, achieving high power efficiency becomes challenging. The main issue is that at high power region close to power amplifier (PA) saturation point the highly non-linear response of the PA leads to significant spectra...

Orthogonal frequency‐division multiplexing (OFDM) has been adopted as the waveform of choice in the existing and emerging broadband wireless communication systems for a number of advantages it can offer. Nevertheless, investigations of more advanced multicarrier transmission schemes have continued with the aim of eliminating or mitigating its essen...

This paper proposes a generalized model and methods for fast-convolution (FC)-based waveform generation and processing with specific applications to fifth generation new radio (5G-NR). Following the progress of 5G-NR standardization in 3rd generation partnership project (3GPP), the main focus is on subband-filtered cyclic prefix (CP) orthogonal fre...

In this article, the first considerations for the fifth generation (5G) New Radio (NR) physical layer evolution to support beyond 52.6 GHz communications are provided. In addition, the performance of orthogonal frequency division multiplexing (OFDM) and discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) modulations are evaluated for beyond 5...

In cyclic-prefix orthogonal frequency-division multiplexing (CP-OFDM) based radio access, the coexistence of different technologies without precise time-frequency synchronization is limited due to high out-of-band emissions. Therefore, spectrum enhancement techniques play a key role to relax the synchronization and power control requirements. This...

According to an aspect, there is provided a waveform processing device (600). Said waveform processing device (600) comprises means for performing the following. Upon receiving one or more input signals (601, 611, 621), each of which corresponds to a different subband, the waveform processing device (600) segments each of the one or more input sign...

High peak-to-average power ratio (PAPR) is a critical problem in orthogonal frequency-division multiplexing (OFDM). The fifth-generation New Radio (5G NR) facilitates the utilization of multiple heterogeneous bandwidth parts (BWPs), which complicates the PAPR problem even further and introduces inter-numerology interference (INI) between the BWPs....

High peak-to-average power ratio (PAPR) is a critical problem in orthogonal frequency-division multiplexing (OFDM). The fifth-generation New Radio (5G NR) facilitates the utilization of multiple heterogeneous bandwidth parts (BWPs), which complicates the PAPR problem even further and introduces inter-numerology interference (INI) between the BWPs....

In cyclic-prefix orthogonal frequency-division multiplexing (CP-OFDM) based radio access, the coexistence of different systems without precise time-frequency synchronization is limited due to high out-of-band emissions. Therefore, filtered-OFDM (F-OFDM) type spectrum enhancement can play a key role to relax the synchronization requirements as it pr...

Cognitive radio (CR) technology with dynamic spectrum management capabilities is widely advocated for utilizing effectively the unused spectrum resources. The main idea behind CR technology is to trigger secondary communications to utilize the unused spectral resources. However, CR technology heavily relies on spectrum sensing techniques which are...

In this paper, we investigate multi-antenna interference rejection combing (IRC) based black-space cognitive radio (BS-CR) operation in time-varying channels. The idea of BS-CR is to transmit secondary user (SU) signal in the same frequency band with the primary user (PU) such that SU’s power spectral density is clearly below that of the PU, and no...

In this work, we provide first-in-class measurement results for fast-convolution-based filtered orthogonal frequency-division multiplexing (FC-F-OFDM) processing implemented on a universal software radio peripheral (USRP) software-defined radio (SDR). The fast-convolution-based filter bank is a highly efficient and flexible scheme allowing to achie...

According to an aspect, there is provided a waveform processing device. The waveform processing device includes circuitry for receiving an input signal including one or more subsequent orthogonal frequency division multiplexing, OFDM, symbol blocks each of which includes a cyclic prefix and an OFDM data block and corresponds to one or more subbands...

In this correspondence paper, we study the peak-to-average power ratio (PAPR) problem in orthogonal frequency-division multiplexing systems. In conventional clipping and filtering based PAPR reduction techniques, clipping noise is allowed to spread over the whole active passband, thus degrading the transmit signal quality similarly at all active su...

Filter-bank based waveform processing has been suggested as an alternative for the plain cyclic-prefix (CP) orthogonal frequency-division multiplexing (OFDM) based schemes in fifth generation (5G) and future wireless communication systems. This is because of the new requirements, such as asynchronous and mixed numerology scenarios supporting multis...

This paper proposes a generalized model and methods for fast-convolution (FC)-based waveform generation and processing with the specific application to fifth generation new radio (5G-NR). Following the progress of 5G-NR standardization in 3rd generation partnership project (3GPP), the main focus is on subband-filtered cyclic prefix (CP) orthogonal...

We study the peak-to-average power ratio (PAPR) problem in orthogonal frequency-division multiplexing (OFDM) systems. In conventional clipping and filtering based PAPR reduction techniques, clipping noise is allowed to spread over the whole active passband, thus degrading the transmit signal quality similarly at all active subcarriers. However, sin...

This paper focuses on multi-antenna interference rejection combing (IRC) based black-space cognitive radio (BS-CR) operation. The idea of BS-CR is to transmit secondary user (SU) signal in the same frequency band with the primary user (PU) such that SU’s power spectral density is clearly below that of the PU, and no significant interference is infl...

Fast Fourier transform (FFT)-domain signal processing has been considered recently as an effective tool for spectrum enhancement of orthogonal frequency-division multiplexing (OFDM)-based waveforms, which is a central element in the fifth generation new radio (5G-NR) developments. Fast-convolution (FC) filtering approximates linear convolution by e...

The data rates as well as quality of service (QoS) requirements for rich user experience in wireless communication services are continuously growing. While consuming a major portion of the energy needed by wireless devices, the wireless transceivers have a key role in guaranteeing the needed data rates with high bandwidth efficiency. The cost of wi...

Several different waveform processing techniques have been studied and proposed for the 5G new radio (NR) physical layer, to support new mixed numerology and asynchronous services. The evaluation and comparison of these different techniques is commonly based on matched waveform processing in the transmitter and receiver units. In this article, it i...

Several different waveform processing techniques have been studied and proposed for the 5G new radio (NR) physical layer, to support new mixed numerology and asynchronous services. The evaluation and comparison of these different techniques is commonly based on matched waveform processing in the transmitter and receiver units. In this article, it i...

In this paper, we address and analyze the receiver reference sensitivity requirements for the 5G New Radio (NR) wireless communications systems, which relate to the SNR requirements at the base station to reach 95 % of the maximum throughput defined for fixed reference channels. Based on the latest 3GPP specifications and evaluation assumptions agr...

High-frequency communications can be flexibly realized using multicarrier modulation (MCM) techniques. How- ever, the HF channels are typically characterized by multipath effects and high Doppler shifts requiring advanced equalization methods for compensating these effects. This paper compares the performance of three widely utilized MCM techniques...

We study positioning of high-speed trains in 5G new radio (NR) networks by utilizing specific NR synchronization signals. The studies are based on simulations with 3GPP-specified radio channel models including path loss, shadowing and fast fading effects. The considered positioning approach exploits measurement of Time-Of-Arrival (TOA) and Angle-Of...

Multicarrier schemes, most often using the Orthogonal Frequency-Division Multiplexing (OFDM) modulation, are now widely adopted in a large number of communication standards. Indeed, to face the constant need of higher and higher data rates, new communication systems always operate on broader bandwidths. Then, multicarrier schemes present clear adva...

This chapter overviews existing work in MIMO-FBMC/OQAM channel estimation and equalization, with emphasis on the more recent developments addressing strong channel frequency selectivity. Both preamble-based and scattered pilots-based schemes for channel estimation are considered. The equalization approaches covered include maximum likelihood sequen...

The introduction of multiple antennas at the transmitter and/or at the receiver provides spatial diversity in the system. This spatial diversity can be exploited using Space Time Block Code (STBC) or Space-Time Trellis Coding (STTC). However, these spatial diversity schemes cannot be straightforwardly applied with FBMC/OQAM due to the intrinsic int...

Future wireless networks demand multicarrier modulation schemes with improved spectrum efficiency and superior spectrum containment. Orthogonal frequency division multiplexing (OFDM) has been the favorite technique in recent developments, but due to its limited spectrum containment, various alternative schemes are under consideration for future sys...

Large databases with Received Signal Strength (RSS) measurements are essential for various use cases in mobile wireless communications and navigation, including radio resource management algorithms and network-based localization. Because of the constantly increasing number of radio transmitters with various wireless technologies and with the advent...

Orthogonal Waveforms and Filter Banks for Future Communication Systems provides an up-to-date account of orthogonal filter bank-based multicarrier (FBMC) systems and their applications in modern and future communications, highlighting the crucial role that advanced multicarrier waveforms play. It is an up-to-date overview of the theory, algorithms,...

Synchronization is a crucial operation in multicarrier systems. Similarly to Orthogonal Frequency-Division Multiplexing (OFDM), FilterBank MultiCarrier with Offset-QAM subcarrier modulation (FBMC/OQAM) systems require good frequency offset and symbol timing synchronization. However they usually have slightly relaxed synchronization requirements wit...

Multicarrier systems suffer from high Peak-to-Average Power Ratio (PAPR). If the High-Power Amplifier (HPA) is operated in its quasilinear region, the high PAPR of the multicarrier signal has no influence on the quality of the transmission. Nevertheless, this situation has a high cost in terms of energy efficiency, especially, for mobile applicatio...

This chapter introduces certain important theories and signal processing tools as background for later developments in this book. After a brief introduction to real and complex linear systems, spectral models for discrete-time systems are formulated in a generalized way and conditions for alias-free sampling are formulated for real and complex base...

The focus in this chapter is on effective practical implementation schemes for the filterbanks, with the main focus on the FilterBank MultiCarrier with Offset-QAM subcarrier modulation (FBMC/OQAM) case. In the first part, effective modulation-based uniform filterbank structures are used, and the designs are defined by the lowpass prototype filter....

This paper investigates the application of flexible fast-convolution (FC) filtering scheme for multiplexing orthogonal frequency-division multiplexing (OFDM) physical resource blocks (PRBs) in a spectrally well-localized manner. This scheme is able to suppress interference leakage between adjacent PRBs, thus supporting independent waveform parametr...

This paper investigates the application of fast-convolution (FC) filtering schemes for flexible and effective waveform generation and processing in the fifth generation (5G) systems. FC-based filtering is presented as a generic multimode waveform processing engine while, following the progress of 5G new radio standardization in the Third-Generation...

Multirate fast convolution (FC) has recently been introduced as an effective tool for communication waveform processing, especially for advanced multicarrier systems targeting at well-contained spectrum. These include filter bank based multicarrier waveforms and filtered OFDM schemes which are receiving increasing attention in the 5G radio access d...

This paper investigates the application of fast-convolution (FC) filtering schemes for flexible and effective waveform generation and processing in 5th generation (5G) systems. FC based filtering is presented as a generic multimode waveform processing engine while, following the progress of 5G new radio (NR) standardization in 3rd Generation Partne...

Multirate fast-convolution (FC) processing can be used for realizing low-complexity filter banks (FBs) and transmultiplexers (TMUXs). The main advantage of the FC based realizations when compared with the polyphase FBs is the increased configurability, that is, the number of subchannels, their bandwidths, and the center frequencies can be adjusted...

Cognitive radio (CR) is considered an important solution to the current spectral scarcity, which is expected to be a significant issue in the next generation of wireless communication systems, namely 5G. Wideband spectrum sharing and sensing constitute highly desirable features of CR systems as they aim to increase the probability of identifying av...

Orthogonal Waveforms and Filter Banks for Future Communication Systems provides an up-to-date account of orthogonal filter bank-based multicarrier (FBMC) systems and their applications in modern and future communications, highlighting the crucial role that advanced multicarrier waveforms play. It is an up-to-date overview of the theory, algorithms,...

With the evolution of 5G wireless communication systems, we have witnessed an increase in the demand for wireless broadband applications and services. However, fixed allocation of the frequency spectrum has led to an under-utilization of the spectral resources, making it hard to find unoccupied bands to deploy new services. To address the spectrum...

This paper investigates the application of flexible and effective fast-convolution (FC) filtering scheme for multiplexing OFDM physical resource blocks (PRBs) in a spectrally well-localized manner. The scheme is able to suppress interference leakage between adjacent PRBs, thus supporting independent waveform parametrization for different PRBs, as w...

One important direction in advanced communication waveform studies for future wireless communications is improved spectrum localization, i.e., minimization of the power leakage outside very narrow guardbands around the useful signal band. This helps to improve the spectrum efficiency and facilitates asynchronous frequency-division multiple access w...

Modern computing platforms offer increasing levels of parallelism for the fast execution of different signal processing tasks. In this paper a digital front-end concept is developed, where the parallel processing is utilized for dividing the inherent structure of IEEE 802.11ac waveform to two or more parallel signals and by processing the resulting...

The coexistence of broadband systems with currently deployed professional mobile radio (PMR) communication systems like public protection and disaster relief has gained much deserved attention. Recently, it has been shown that a conventional orthogonal frequency division multiplexing (OFDM)-based long-term evolution (LTE) system needs sufficient gu...

High-frequency (HF) communications can be flexibly realized using multicarrier modulation techniques. This paper compares the performance of three widely utilized MCM techniques, namely, orthogonal frequency-division multiplexing (OFDM), filter bank multicarrier/offset-QAM (FBMC/OQAM), and filtered multitone (FMT) in HF communications. The performa...

One important direction in advanced communication waveform studies for future wireless communications is improved spectrum localization, i.e., minimization of the power leakage outside very narrow guardbands around the useful signal band. This helps to improve the spectrum efficiency, especially in difficult radio access scenarios, like cognitive r...

The present work proposes a subband energy detection method that performs efficiently under noise uncertainty (NU) and frequency-selective channels. The critical impact of detrimental modeling uncertainties, such as NU, is analytically quantified and it is shown that the introduced method is robust to both NU and frequency-selectivity conditions. T...

Green communication and energy saving have been a critical issue in modern wireless communication systems. The concepts of energy harvesting and energy transfer are recently receiving much attention in academic research field. In this paper, we study energy cooperation problems based on save-then-transmit protocol and propose two energy cooperation...

This paper investigates the use of effective and flexible fast-convolution (FC) filtering scheme for multiplexing OFDM resource blocks (RBs) in a spectrally well-localized manner. The scheme is able to effectively suppress interference leakage between adjacent RBs, thus supporting asynchronous operation and indepen dent waveform parametrization of...