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Pooi Yuen Kam - One of the best experts on this subject based on the ideXlab platform.

  • A Refinement to the Viterbi-Viterbi Carrier Phase Estimator and an Extension to the Case With a Wiener Carrier Phase Process
    IEEE Access, 2019
    Co-Authors: Tianyu Song, Pooi Yuen Kam
    Abstract:

    We provide a theoretical foundation for further analysis and optimization of the Mth-power (MP) Carrier Phase estimator for MPSK modulation. Also known as the Viterbi-Viterbi (VV) estimator, it is commonly used in practice because it leads to low-latency receiver implementations. The MP Carrier Phase estimator first raises the received noisy signal samples to the Mth-power to remove the unknown Phase modulation, and then extracts the unknown Carrier Phase of the mid-symbol using a weighted sum of these modulation-wiped-off received signal samples over a symmetrical observation window. Our starting point is the single-term, complex exponential expression for a complex sinusoid received in complex, additive, white, Gaussian noise (AWGN), which leads to a great deal of simplicity in dealing with arbitrary powers of the noisy received signal sample when compared with the conventional approach of raising the sum of signal plus noise to higher powers. The single-exponential expression enables us to first optimize the weighting coefficients of the MP Carrier Phase estimator with respect to the statistics of the AWGN, in a manner much simpler than previous approaches. Then, it enables us to apply the linear minimum mean square error (LMMSE) criterion to optimize the MP estimator with respect to both the statistics of the AWGN and the Carrier Phase noise that we model here as a Wiener process. Although the LMMSE MP estimator is computationally intensive for online implementation, a much less complex version is suggested that can be efficiently implemented in real time. Extensive simulation results are presented to demonstrate the improved performance of the LMMSE MP estimator over the conventional MP estimator. By using a sufficiently long symmetrical observation window, the LMMSE estimator does not suffer from the block length effect, which leads to much performance gain over the VV/MP estimator especially at high signal-to-noise ratio (SNR) and high Phase noise. A Phase unwrapping algorithm is also presented for accurate unwrapping of the estimated Carrier Phase before it is used in data detection. The proposed LMMSE Carrier Phase estimator is suitable for implementing a coherent receiver at all SNRs.

  • Adaptive estimation of MPSK sequences with unknown Carrier Phase characteristics
    The 8th International Conference on Communication Systems 2002. ICCS 2002., 1
    Co-Authors: Pooi Yuen Kam, Yan Kwong Chiang
    Abstract:

    Kam and Sinha (1995) have proposed a Viterbi-type algorithm for efficient estimation of both coded and uncoded MPSK sequences received over the AWGN channel with unknown Carrier Phase. The aim is to achieve the BEP performance of coherent detection. The metric for choosing the survivors employed by Kam et al. is non-adaptive in that the observation window length for forming the metric is fixed, and is chosen a priori based on knowledge of the fluctuation rate of the Carrier Phase. The work here seeks to render the algorithm adaptive by developing a decision metric that can be adjusted to achieve coherent node error event probability without prior knowledge of the Carrier Phase characteristics. The metric is based on the use of a first-order adaptive filter for Carrier reference tracking. The input gain of the filter is adapted on-line based on the received signal samples. The resulting receiver structure can be interpreted as a per survivor processing receiver. Both analytical and simulation results are presented to show that the receiver performs well in the presence of both static and time-varying Carrier Phase processes.

Dan Raphaeli - One of the best experts on this subject based on the ideXlab platform.

  • Joint Carrier Phase Estimation and Turbo Decoding Using Bit Carrier Phase APP Decoder
    IEEE Transactions on Communications, 2007
    Co-Authors: A. Saroka, Dan Raphaeli
    Abstract:

    In this paper, we present an algorithm for joint Carrier Phase estimation and turbo decoding for the case of rapidly varying Carrier Phase during the transmitted block. The proposed algorithm shows improved performance over previously proposed communication schemes, both coherent and noncoherent, for channels with additive white Gaussian noise and high Carrier Phase noise. The novel algorithm utilizes a modified "two dimensional" bit Carrier Phase a posteriori probability (BCAPP) decoder containing additional states representing the received Carrier Phase. The BCAPP decoder calculates two extrinsic metrics: one representing the bit soft value and the other representing the received Carrier Phase probability density function approximation. A modified structure of the turbo code iterations is suggested, implementing separate propagation of the two metrics between the BCAPP decoders. One additional attractive property of the suggested algorithm is its robustness against Phase noise model mismatch.

  • Transactions Papers Joint Carrier Phase Estimation and Turbo Decoding Using Bit Carrier Phase APP Decoder
    2007
    Co-Authors: A. Saroka, Dan Raphaeli
    Abstract:

    In this paper, we present an algorithm for joint car- rier Phase estimation and turbo decoding for the case of rapidly varying Carrier Phase during the transmitted block. The proposed algorithm shows improved performance over previously proposed communication schemes, both coherent and noncoherent, for chan- nels with additive white Gaussian noise and high Carrier Phase noise. The novel algorithm utilizes a modified "two dimensional" bit Carrier Phase a posteriori probability (BCAPP) decoder con- taining additional states representing the received Carrier Phase. The BCAPP decoder calculates two extrinsic metrics: one repre- senting the bit soft value and the other representing the received Carrier Phase probability density function approximation. A modi- fied structure of the turbo code iterations is suggested, implement- ing separate propagation of the two metrics between the BCAPP decoders. One additional attractive property of the suggested al- gorithm is its robustness against Phase noise model mismatch. IndexTerms—Decoding algorithms, error correction codes, non- coherent reception, Phase decoding.

Tianyu Song - One of the best experts on this subject based on the ideXlab platform.

  • A Refinement to the Viterbi-Viterbi Carrier Phase Estimator and an Extension to the Case With a Wiener Carrier Phase Process
    IEEE Access, 2019
    Co-Authors: Tianyu Song, Pooi Yuen Kam
    Abstract:

    We provide a theoretical foundation for further analysis and optimization of the Mth-power (MP) Carrier Phase estimator for MPSK modulation. Also known as the Viterbi-Viterbi (VV) estimator, it is commonly used in practice because it leads to low-latency receiver implementations. The MP Carrier Phase estimator first raises the received noisy signal samples to the Mth-power to remove the unknown Phase modulation, and then extracts the unknown Carrier Phase of the mid-symbol using a weighted sum of these modulation-wiped-off received signal samples over a symmetrical observation window. Our starting point is the single-term, complex exponential expression for a complex sinusoid received in complex, additive, white, Gaussian noise (AWGN), which leads to a great deal of simplicity in dealing with arbitrary powers of the noisy received signal sample when compared with the conventional approach of raising the sum of signal plus noise to higher powers. The single-exponential expression enables us to first optimize the weighting coefficients of the MP Carrier Phase estimator with respect to the statistics of the AWGN, in a manner much simpler than previous approaches. Then, it enables us to apply the linear minimum mean square error (LMMSE) criterion to optimize the MP estimator with respect to both the statistics of the AWGN and the Carrier Phase noise that we model here as a Wiener process. Although the LMMSE MP estimator is computationally intensive for online implementation, a much less complex version is suggested that can be efficiently implemented in real time. Extensive simulation results are presented to demonstrate the improved performance of the LMMSE MP estimator over the conventional MP estimator. By using a sufficiently long symmetrical observation window, the LMMSE estimator does not suffer from the block length effect, which leads to much performance gain over the VV/MP estimator especially at high signal-to-noise ratio (SNR) and high Phase noise. A Phase unwrapping algorithm is also presented for accurate unwrapping of the estimated Carrier Phase before it is used in data detection. The proposed LMMSE Carrier Phase estimator is suitable for implementing a coherent receiver at all SNRs.

Washington Yotto Ochieng - One of the best experts on this subject based on the ideXlab platform.

  • The Carrier-multipath observable: a new Carrier-Phase multipath mitigation technique
    Gps Solutions, 2014
    Co-Authors: Ramin Moradi, Altti Jokinen, Shaojun Feng, Wolfgang Schuster, Washington Yotto Ochieng
    Abstract:

    Modeling and mitigating Carrier-Phase multipath errors continue to be a significant challenge for high-accuracy positioning using global navigation satellite systems. The multipath error is dependent on the operational environment and therefore cannot be mitigated by differencing techniques. The effect of multipath is accentuated when observables based on linear combinations of measurements from two or more frequencies are formulated. We develop a new Carrier-Phase multipath error observable that isolates the inter-frequency Carrier-Phase multipath error for linear combinations of observables, such as wide-lane (WL). Real-time kinematic positioning results from varying baseline lengths show that a significant reduction in between 14 and 47 % in the time to initial ambiguity resolution are achieved by correcting the WL observable using the new Carrier-Phase multipath error observable.

A. Saroka - One of the best experts on this subject based on the ideXlab platform.

  • Joint Carrier Phase Estimation and Turbo Decoding Using Bit Carrier Phase APP Decoder
    IEEE Transactions on Communications, 2007
    Co-Authors: A. Saroka, Dan Raphaeli
    Abstract:

    In this paper, we present an algorithm for joint Carrier Phase estimation and turbo decoding for the case of rapidly varying Carrier Phase during the transmitted block. The proposed algorithm shows improved performance over previously proposed communication schemes, both coherent and noncoherent, for channels with additive white Gaussian noise and high Carrier Phase noise. The novel algorithm utilizes a modified "two dimensional" bit Carrier Phase a posteriori probability (BCAPP) decoder containing additional states representing the received Carrier Phase. The BCAPP decoder calculates two extrinsic metrics: one representing the bit soft value and the other representing the received Carrier Phase probability density function approximation. A modified structure of the turbo code iterations is suggested, implementing separate propagation of the two metrics between the BCAPP decoders. One additional attractive property of the suggested algorithm is its robustness against Phase noise model mismatch.

  • Transactions Papers Joint Carrier Phase Estimation and Turbo Decoding Using Bit Carrier Phase APP Decoder
    2007
    Co-Authors: A. Saroka, Dan Raphaeli
    Abstract:

    In this paper, we present an algorithm for joint car- rier Phase estimation and turbo decoding for the case of rapidly varying Carrier Phase during the transmitted block. The proposed algorithm shows improved performance over previously proposed communication schemes, both coherent and noncoherent, for chan- nels with additive white Gaussian noise and high Carrier Phase noise. The novel algorithm utilizes a modified "two dimensional" bit Carrier Phase a posteriori probability (BCAPP) decoder con- taining additional states representing the received Carrier Phase. The BCAPP decoder calculates two extrinsic metrics: one repre- senting the bit soft value and the other representing the received Carrier Phase probability density function approximation. A modi- fied structure of the turbo code iterations is suggested, implement- ing separate propagation of the two metrics between the BCAPP decoders. One additional attractive property of the suggested al- gorithm is its robustness against Phase noise model mismatch. IndexTerms—Decoding algorithms, error correction codes, non- coherent reception, Phase decoding.