Signal Design for Ultra-wideband Radio

Scholtz, R.A.; Kumar, P. Vijay; Corrada-Bravo, Carlos J.

doi:10.1007/978-1-4471-0673-9_5

Cited by 23 publications

(20 citation statements)

References 3 publications

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“…The chip duration is set to T c = 4ns, and the pulse pair spacing T d and the guard time T g are 20ns. The TH sequence is constructed from the algorithm proposed in [28] with N T H = N f = 11 and T f = 88ns.…”

Section: Numerical Resultsmentioning

confidence: 99%

Hybrid Ultrawideband Modulations Compatible for Both Coherent and Transmit-Reference Receivers

Zhao

Orlik

Molisch³

et al. 2007

IEEE Trans. Wireless Commun.

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This paper considers signaling schemes for heterogeneous ultrawideband communications networks that contain both coherent (rake) and transmitted-reference (TR) receivers. While coherent receivers are capable of receiving TR signals, they do so with a 3 dB penalty, because they cannot make use of the energy invested into the reference pulse. We propose a new signaling scheme that avoids this drawback, by encoding redundant information on the reference pulse. The resulting scheme does not affect the operation of a TR receiver, while recovering the 3 dB penalty and furthermore providing an additional 1.7 dB coding gain to a coherent uncoded binary scheme. This can be explained by interpreting the scheme as a trellis-coded modulation. We also provide an alternative implementation that can be viewed as a recursive systematic convolutional encoder. Combining this version further with a simple forward error correction encoder results in a concatenated code that can be decoded iteratively, providing a bit-error rate of 10-3 at 2.8 dB signal-to-noise ratio in additive white Gaussian noise. The convergence behavior of this iterative code is analyzed by using extrinsic information transfer charts. IEEE Transactions on Wireless CommunicationsThis work may not be copied or reproduced in whole or in part for any commercial purpose. Permission to copy in whole or in part without payment of fee is granted for nonprofit educational and research purposes provided that all such whole or partial copies include the following: a notice that such copying is by permission of Mitsubishi Electric Research Laboratories, Inc.; an acknowledgment of the authors and individual contributions to the work; and all applicable portions of the copyright notice. Copying, reproduction, or republishing for any other purpose shall require a license with payment of fee to Mitsubishi Electric Research Laboratories, Inc. All rights reserved. Abstract-This paper considers signaling schemes for heterogeneous ultrawideband communications networks that contain both coherent (rake) and transmitted-reference (TR) receivers. While coherent receivers are capable of receiving TR signals, they do so with a 3 dB penalty, because they cannot make use of the energy invested into the reference pulse. We propose a new signaling scheme that avoids this drawback, by encoding redundant information on the reference pulse. The resulting scheme does not affect the operation of a TR receiver, while recovering the 3 dB penalty and furthermore providing an additional 1.7 dB coding gain to a coherent uncoded binary scheme. This can be explained by interpreting the scheme as a trellis-coded modulation. We also provide an alternative implementation that can be viewed as a recursive systematic convolutional encoder. Combining this version further with a simple forward error correction encoder results in a concatenated code that can be decoded iteratively, providing a bit-error rate of 10 −3 at 2.8 dB signal-to-noise ratio in additive white Gaussian noise. The convergence beh...

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Section: Numerical Resultsmentioning

confidence: 99%

Hybrid Ultrawideband Modulations Compatible for Both Coherent and Transmit-Reference Receivers

Zhao

Orlik

Molisch³

et al. 2007

IEEE Trans. Wireless Commun.

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“…This kind of unfolding results in a doubling of the upper bound on the number of matching columns [9]. The worst case correlation are also doubled (approximately).…”

Section: B Communicationsmentioning

confidence: 97%

Matrix construction using cyclic shifts of a column

Tirkel

Hall

2005

Proceedings. International Symposium on Information Theory, 2005. ISIT 2005.

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Abstract-This paper describes the synthesis of matrices with good correlation, from cyclic shifts of pseudonoise columns. Optimum matrices result whenever the shift sequence satisfies the constant difference property. Known shift sequences with the constant (or almost constant) difference property are: Quadratic (Polynomial) and Reciprocal Shift modulo prime, Exponential Shift, Legendre Shift, Zech Logarithm Shift, and the shift sequences of some m-arrays. We use these shift sequences to produce arrays for watermarking of digital images. Matrices can also be unfolded into long sequences by diagonal unfolding (with no deterioration in correlation) or row-by-row unfolding, with some degradation in correlation.

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“…Besides the maximum transmitted power, note that the power spectral density of the signal is also constrained in UWB systems. According to [3], [9], the parameters N f and N c both contribute to the power spectral density whereas the exact contribution is only quantifiable for known TH codes. In this case, for the general analysis with any TH codes, we ignore the influence of N c and N f on the shape of power spectrum, and assume a constant maximum transmitted power.…”

Section: A Fixed Transmitted Powermentioning

confidence: 99%

“…According to the methods of constructing TH codes described in [2], [3], the normalized maximum of unmatched autocorrelation φ can be a constant as long as N f = N c , that is, C m will be a constant. We choose the TH code from Table 1 in [3] as an example, where N f and N c both equal to 11, and C m equals to 2.…”

Section: Numerical Examplesmentioning

confidence: 99%

“…We suppose a suitable modulation method (such as bipolar modulation) is applied here. It has been shown that the autocorrelation of TH codes is some kind of coincidence autocorrelation and equals to the number of overlapped positions [2], [3] (we restrict ourselves to the case of pure TH codes where no amplitude information of codes is utilized). The property of autocorrelation is highly related to the relationship between the number of chip positions in a frame (N c ) and National ICT Australia is funded by the Australian Government's Department of Communications, Information Technology and the Arts and the Australian Research Council through Backing Australia's Ability and the ICT Centre of Excellence program.…”

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confidence: 99%

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Performance and parameter optimization of UWB RAKE reception with interchip interference

Zhang

Kennedy

Abhayapala

IEEE International Conference on Communications, 2005. ICC 2005. 2005

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Abstract-In this paper, performance and parameter optimization of RAKE reception for time-hopping Ultra Wideband (TH-UWB) systems is investigated when interchip interference (ICI) is taken into consideration. For a TH-UWB system, ICI is closely related to the relationship between the number of chips in a frame (N c ), and the period of the TH code (N f ). In a fixed datarate case, larger N f implies higher transmitted symbol signal-tonoise ratio (SNR) and larger ICI in RAKE fingers. So there is a tradeoff between N c and N f to optimize the RAKE performance. In this paper, two models are suggested to describe the ICI, and this tradeoff is investigated in the single user case based on the traditional Gaussian approximation method and other flexible methods. Given the lack of explicit knowledge of the relationship among N f , Nc and the interference, a rule of thumb is proposed to configure N f and Nc.

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Signal Design for Ultra-wideband Radio

Cited by 23 publications

References 3 publications

Hybrid Ultrawideband Modulations Compatible for Both Coherent and Transmit-Reference Receivers

Hybrid Ultrawideband Modulations Compatible for Both Coherent and Transmit-Reference Receivers

Matrix construction using cyclic shifts of a column

Performance and parameter optimization of UWB RAKE reception with interchip interference

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