Multi-gigabit microwave and millimeter-wave communications research at CSIRO

© 2014 IEEE. High speed and long range wireless backhauls are cost-effective alternatives to fibre networks and becoming more and more attractive as the demand for broadband wireless services grows rapidly in recent years. However, current commercially available wireless backhaul systems neither provide sufficiently high speed nor meet the requirements to achieve both high speed and long range at the same time with sufficiently low latency for targeted applications. Traditional microwave systems can achieve long transmission range, but the data rates are limited to a few hundred Mega bits per second only. Multi-Gigabit wireless communications can be achieved using millimetre-wave (mm-wave) frequency bands, especially the E-bands, but the practical transmission range is still a major weakness. In this paper, the state-of-the-art microwave and mm-wave technologies developed at the Commonwealth Scientific and Industrial Research Organization (CSIRO) are introduced to demonstrate CSIRO's technology leadership in multi-Gigabit wireless communications research and development. The technology trends in multi-Gigabit wireless communications are also discussed and various recently developed microwave and mm-wave systems are compared. It is hoped that this paper will stimulate further research interest and industry development

A new transform-domain regularized recursive least M-estimate algorithm for a robust linear estimation

This brief proposes a new transform-domain (TD) regularized M-estimation (TD-R-ME) algorithm for a robust linear estimation in an impulsive noise environment and develops an efficient QR-decomposition-based algorithm for recursive implementation. By formulating the robust regularized linear estimation in transformed regression coefficients, the proposed TD-R-ME algorithm was found to offer better estimation accuracy than direct application of regularization techniques to estimate system coefficients when they are correlated. Furthermore, a QR-based algorithm and an effective adaptive method for selecting regularization parameters are developed for recursive implementation of the TD-R-ME algorithm. Simulation results show that the proposed TD regularized QR recursive least M-estimate (TD-R-QRRLM) algorithm offers improved performance over its least squares counterpart in an impulsive noise environment. Moreover, a TD smoothly clipped absolute deviation R-QRRLM was found to give a better steady-state excess mean square error than other QRRLM-related methods when regression coefficients are correlated. © 2006 IEEE.published_or_final_versio

A new regularized transform-domain NLMS adaptive filtering algorithm

The transform domain normalized LMS (TD-NLMS)-adaptive filtering algorithm is an efficient adaptive filter with fast convergence speed and reasonably low arithmetic complexity. However, it is sensitive to the level of the excitation signal, which may vary significantly over time in speech and audio signals. This paper proposes a new regularized transform domain NLMS (R-TDNLMS) algorithm and studies its mean and mean square convergence performance. The proposed algorithm extends the conventional TDNLMS algorithm by imposing a regularization term on the coefficients to reduce the variance of the estimator. The mean and mean square convergence behaviors of the proposed algorithm are studied to characterize its convergence condition and steady-state excess mean squares error (MSE). It shows that regularization can help to reduce the MSE for coloured inputs by trading slight bias for variance. Moreover, the immunity to varying input signal level is significantly reduced. Computer simulations are conducted to examine the effectiveness of the proposed algorithm and they are in good agreement with the theoretical analysis. © 2010 IEEE.published_or_final_versionThe 2010 IEEE Asia Pacific Conference on Circuits and Systems (APCCAS 2010), Kuala Lumpur, Malaysia, 6-9 December 2010. In Proceedings of APCCAS, 2010, p. 696-69

Unified out-of-band emission reduction with linear complexity for OFDM

© 2014 IEEE. This paper proposes a unified out-of-band emission (OOBE) reduction framework with linear complexity for orthogonal frequency-division multiplexing (OFDM) systems. Unlike conventional spectral precoding approaches which use orthogonal precoding matrixes, this framework composes cancellation signals from the linear combinations of data symbols and minimizes the average OOBE power with a general least-squares solution. A joint frequency domain cancellation subcarrier and data domain cancellation symbol allocation scheme is also proposed for discrete Fourier transform precoded OFDM, by which the overall signal processing complexity of the OFDM transceiver is further reduced without impact on other system performance. The advantages of the proposed scheme is verified both analytically and by simulation as compared with some well-known low-complexity OOBE reduction schemes

A new regularized QRD recursive least M-estimate algorithm: Performance analysis and applications

Proceedings of the International Conference on Green Circuits and Systems, 2010, p. 190-195This paper proposes a new regularized QR decomposition based recursive least M-estimate (R-QRRLM) adaptive filtering algorithm and studies its mean and mean square convergence performance and application to acoustic echo cancellation (AEC). The proposed algorithm extends the conventional RLM algorithm by imposing a weighted L2 regularization term on the coefficients to reduce the variance of the estimator. Moreover, a QRD-based algorithm is employed for efficient recursive implementation and improved numerical property. The mean convergence analysis shows that a bias solution to the classical Wiener solution will be introduced due to the regularization. The steady-state excess mean square error (EMSE) is derived and it suggests that the variance will decrease while the bias will increase with the regularization parameter. Therefore, regularization can help to trade bias for variance. In this study, the regularization parameter can be adaptively selected and the resultant variable regularization parameter QRRLM (VR-QRRLM) algorithm can obtain both high immunity to input variation and low steady-state EMSE values. The theoretical results are in good agreement with simulation results. Computer simulation results on AEC show that the R-QRRLM and VR-QRRLM algorithms considerably outperform the traditional RLS algorithm when the input signal level is low or during double talk. © 2010 IEEE.published_or_final_versio

Joint transmitter and receiver I/Q imbalance estimation in presence of carrier frequency offset

© 2015 IEEE. This paper proposes a simple frequency domain joint transmitter and receiver I/Q imbalance estimation method which exploits the phase rotation introduced by carrier frequency offset. Using two frequency domain training sequences inserted in each transmission frame, the transmitter and receiver I/Q imbalances can be jointly estimated over multiple frames. The transmitter I/Q imbalance parameter can be fed back to the transmitter for I/Q imbalance pre-compensation, whereas the receiver I/Q imbalance can be compensated locally followed by conventional frequency domain equalization. Numerical simulation results show that the image rejection ratios for both transmitter and receiver after I/Q imbalance compensation can be improved to over 50 dB which is necessary for multichannel systems with high order modulation and wide transmission bandwidth

Thin broadband noise absorption through acoustic reactance control by electro-mechanical coupling without sensor

published_or_final_versio

Low-frequency noise absorption by a shunted loudspeaker

Session - Duct Acousticspublished_or_final_versio

Polymorphism and association of microsatellite SJ01 with birth weight and early growth traits in pigs

Myostatin is a negative regulator of animal skeletal muscle development and SJ01 is a microsatellite locus flanking porcine myostatin gene. In the present study, the polymorphism of microsatellite SJ01 in three pig populations, that is, Duroc (n = 420), Yorkshire (n = 414) and Landrace (n = 119), were investigated, and its associations with birth weight and early growth traits were analyzed. The results indicated that genotype BB was predominant in Yorkshire pigs and allele B was predominant in both Yorkshire and Landrace pigs, whereas allele A was more prevalent in Duroc pigs. Among the three pig breeds, Duroc population had the highest heterozygosity and deviated from Hardy-Weinberg equilibrium (P < 0.05). The average daily gain from 28 d to 70 d in Yorkshire pigs and the body weight at 70 d in Landrace pigs were significantly different between SJ01 genotypes (P < 0.05). These resultssuggest that microsatellite SJ01 is a potential DNA marker for early growth trait selection in Yorkshire and Landrace pigs as well as for refining QTL for early growth traits on SSC15

Low-Complexity Digital Modem Implementation for High-Speed Point-To-Point Wireless Communications

© 2018 IEEE. A low-complexity digital modem is presented in this paper for achieving high-speed and wideband point-To-point (P2P) wireless communications. By combining multiple functionalities into the transmitter and receiver filters, the signal processing complexity in the digital baseband can be significantly reduced. The structures and the implementation using field programmable gate array (FPGA) for the transmitter and receiver filters are described in details. Pre-equalization for reducing the impact of practical channel frequency response can be easily incorporated into the transmitter filter structure. The experimental test results using a 20 Gigabits per second (Gbps) digital modem prototype demonstrate the satisfactory performance with low FPGA resource usage