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21
Generalized ReedMuller Codes and Power Control in OFDM Modulation
 IEEE Trans. Inform. Theory
, 2000
"... encoding, power, ..."
GolayDavisJedwab Complementary Sequences and RudinShapiro Constructions
 IEEE TRANS. INFORM. THEORY
, 2001
"... A Golay Complementary Sequence (CS) has a PeaktoAveragePowerRatio (PAPR) ≤ 2.0 for its onedimensional continuous Discrete Fourier Transform (DFT) spectrum. Davis and Jedwab showed that all known length 2 m CS, (GDJ CS), originate from certain quadratic cosets of ReedMuller (1, m). These can b ..."
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Cited by 10 (4 self)
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A Golay Complementary Sequence (CS) has a PeaktoAveragePowerRatio (PAPR) ≤ 2.0 for its onedimensional continuous Discrete Fourier Transform (DFT) spectrum. Davis and Jedwab showed that all known length 2 m CS, (GDJ CS), originate from certain quadratic cosets of ReedMuller (1, m). These can be generated using the RudinShapiro construction. This paper shows that GDJ CS have a PAPR ≤ 2.0 under all 2 m ×2 m unitary transforms whose rows are unimodular linear (Linear Unimodular Unitary Transforms (LUUTs)), including one and multidimensional generalised DFTs. In this context we define Constahadamard Transforms (CHTs) and show how all LUUTs can be formed from tensor combinations of CHTs. We also propose tensor cosets of GDJ sequences arising from RudinShapiro extensions of nearcomplementary pairs, thereby generating many more infinite sequence families with tight low PAPR bounds under LUUTs. We m m−⌊ then show that GDJ CS have a PAPR ≤ 2 2 ⌋ under all 2m × 2m unitary transforms whose rows are linear (Linear Unitary Transforms (LUTs)). Finally we present a radix2 tensor decomposition of any 2 m × 2 m LUT.
An Enhanced Method for Measuring the Performance of Multirate Systems
 In Proc. Int. Conf. on Digital Signal Processing, Limassol
, 1995
"... Many signal processing structures of practical interest belong to the class of linear periodically timevarying (LPTV) systems. Important examples are multirate systems such as filter banks for image or speech coding. In general, periodic timevariance results in aliasing distortions and imaging tha ..."
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Cited by 4 (2 self)
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Many signal processing structures of practical interest belong to the class of linear periodically timevarying (LPTV) systems. Important examples are multirate systems such as filter banks for image or speech coding. In general, periodic timevariance results in aliasing distortions and imaging that must be carefully considered during system design and implementation. Furthermore, datapath quantizations cause noiselike cyclostationary distortions. Based on a new systemtheoretical description of LPTV systems, a method is described which allows the measurement of such errors in digital systems. To illustrate the described method, measurement results are presented. 1 Introduction In implemented multirate systems different types of deviations from the desired behavior may be observed. First of all, coefficient quantization results in a linear system which differs to some extent from the desired one. In addition, aliasing distortions and imaging caused by down and upsampling have to ...
Precoding in Multicode DSCDMA Systems
 in Proc. IEEE Int. Symp. Info
, 1997
"... A precoded multicode directsequence codedivision multipleaccess system is proposed and analyzed. Its main merits are decreased envelope variations and increased performance. I. Introduction It is expected that future mobile personal communication systems require many different data rates from a ..."
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Cited by 4 (0 self)
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A precoded multicode directsequence codedivision multipleaccess system is proposed and analyzed. Its main merits are decreased envelope variations and increased performance. I. Introduction It is expected that future mobile personal communication systems require many different data rates from a few kbit/s to about 1 Mbit/s or more, at different qualities of service. The recently suggested multicode DSCDMA system [?] is one solution which may offer this flexibility. However, in a multicode system the transmitted signal consists of a sum over many independently spread signals, causing large variations in the envelope. These envelope variations decrease the efficiency of the power amplifier significantly. Thus, in practice, the data rate for a multicode system is limited to relatively low rates. II. System Model Each user is assigned n different spreading codes, fc j g n j=1 , consisting of N chips f\Sigma1g. Assuming BPSK modulation the transmitted signal is s(t) = \Gamma P 1 ...
ATM Without Strings: An Overview of Wireless ATM
 IEEE Conference on Personal Wireless Communications (ICPWC '96
, 1996
"... A majority of applications in the nearfuture are expected to be multimediacapable. One of the enabling technologies for this to happen is Asynchronous Transfer Mode (ATM) networking. In addition, the exploding use of mobile terminals  laptop computers, personal digital assistants (PDAs) etc.  ..."
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Cited by 2 (0 self)
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A majority of applications in the nearfuture are expected to be multimediacapable. One of the enabling technologies for this to happen is Asynchronous Transfer Mode (ATM) networking. In addition, the exploding use of mobile terminals  laptop computers, personal digital assistants (PDAs) etc.  means there will be more demand to extend these multimediacapable applications to the mobile terminal. This requires the extension of ATM technology to highspeed wireless communications (? 20 Mbps). This is an active area of research around the world. This talk will describe the technical challenges posed by wireless ATM networking and give an overview of wireless ATM efforts under way, focusing on specific research projects in the USA and Europe. 1 Introduction A majority of applications in the nearfuture are expected to be multimediacapable. One of the enabling technologies for this to happen is Asynchronous Transfer Mode (ATM) networking. While these applications will be primarily...
Compact Description of Golay Sequences and Their Extensions
, 1997
"... We introduce new techniques to derive compact descriptions of Golay sequences and their extensions. In particular we show how a fundamental notion of commutative algebra, namely the notion of Grobner bases, can be successfully employed to give compact description of Golay sequences. We then conce ..."
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Cited by 1 (0 self)
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We introduce new techniques to derive compact descriptions of Golay sequences and their extensions. In particular we show how a fundamental notion of commutative algebra, namely the notion of Grobner bases, can be successfully employed to give compact description of Golay sequences. We then concentrate on the practically important case of Golay sequences of length 2 n . For those sequences we give a recursive definition of a subset of size 2 n n!, which we conjecture to coincide with the set of Golay sequences. Key words: Golay sequences, polyphase sequences, multitone, Grobner basis 1 Introduction In 1951, and more detailed in 1961, Golay investigated special pairs of \Sigma1 sequences, which he called complementary pairs, for their use in spectrometry, [1, 2], see also [3]. These are pairs of sequences of length N such that their aperiodic autocorrelations add up to an impulse of magnitude 2N . More precisely, let x; y 2 f\Sigma1g N . We say that x and y are complementa...
On Synchronization of Opportunistic Radio OFDM Systems
"... Abstract—In this paper we present a study on pilot aided time and frequency synchronization for Opportunistic Radio (OR) OFDM systems which apply adaptive subcarrier allocation techniques to either avoid narrow band interference or to prevent licensed spectrum owners (so called primary users) from h ..."
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Abstract—In this paper we present a study on pilot aided time and frequency synchronization for Opportunistic Radio (OR) OFDM systems which apply adaptive subcarrier allocation techniques to either avoid narrow band interference or to prevent licensed spectrum owners (so called primary users) from harmful disturbance. The variable subcarrier allocation of OR OFDM requires adaptive preamble designs to use stateoftheart OFDM synchronization methods. Since these synchronization algorithms mainly require repetitive timedomain pilot structures, the novel task of providing repetitive pilot signals under arbitrary subcarrier allocations is addressed in the paper. Furthermore we analyze the stochastic characteristics of the OROFDM carrier frequency offset synchronization procedure. I.
The Frequency Domain Behavioral Modeling and Simulation of Nonlinear Analog Circuits and Systems
, 1993
"... LUNSFORD II, PHILIP J. The Frequency Domain Behavioral Modeling and Simulation of Nonlinear Analog Circuits and Systems. (Under the direction of Michael B. Steer.) A new technique for the frequencydomain behavioral modeling and simulation of nonautonomous nonlinear analog subsystems is presented. ..."
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LUNSFORD II, PHILIP J. The Frequency Domain Behavioral Modeling and Simulation of Nonlinear Analog Circuits and Systems. (Under the direction of Michael B. Steer.) A new technique for the frequencydomain behavioral modeling and simulation of nonautonomous nonlinear analog subsystems is presented. This technique extracts values of the Volterra nonlinear transfer functions and stores these values in binary files. Using these files, the modeled substem can be simulated for an arbitrary periodic input expressed as a finite sum of sines and cosines. Furthermore, the extraction can be based on any circuit simulator that is capable of steady state simulation. Thus a large system can be divided into smaller subsystems, each of which is characterized by circuit level simulations or lab measurements. The total system can then be simulated using the subsystem characterization stored as tables in binary files.
On the PAPR of Binary ReedMuller OFDM Codes
"... We present a lower bound on the Peak to Average Power Ratio (PAPR) for the second order cosets of binary ReedMuller code by classifying the codewords using their Walsh Hadamard Transform (WHT) vectors. ..."
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We present a lower bound on the Peak to Average Power Ratio (PAPR) for the second order cosets of binary ReedMuller code by classifying the codewords using their Walsh Hadamard Transform (WHT) vectors.