Based on the good time-frequency localization of the wavelet packet modulation （WPM） system and the analysis of the muhitone （MT） interference, an improved WPM narrow band interference （NBI） rejection system usi...Based on the good time-frequency localization of the wavelet packet modulation （WPM） system and the analysis of the muhitone （MT） interference, an improved WPM narrow band interference （NBI） rejection system using an adaptive least mean square （LMS） algorithm is discussed in this paper. In the WPM interference rejection system, according to the structure of the wavelet packet tree （WFF） and the characteristic of the MT interference, the demodulated WPM signal which contains the interference component is filtered using an adaptive LMS filtering implementation. Theoretical analysis and simulation resuits show that the proposed method improves the bit error rate （BER） performance of the WPM system in the presence of MT interference.展开更多
The Least Mean Square(LMS)adaptive filtering algorithm is a significant filtering algorithm widely used in noise processing and other fields that automatically adjusts the values of filter coefficients according to th...The Least Mean Square(LMS)adaptive filtering algorithm is a significant filtering algorithm widely used in noise processing and other fields that automatically adjusts the values of filter coefficients according to the results,aimed at optimizing the filtered results.Based on a basic serial LMS adaptive filtering algorithm,we propose a vectorized parallel processing scheme for the LMS adaptive filtering algorithm in this work.By combining the characteristics of the algorithm processing flow and those of the parallel technologies used in vector Digital Signal Processes(DSPs),the optimizations such as loop fusion,double-word accessing,and vector shuffling of the LMS algorithm are studied in depth,and the loop unrolling optimization method is used to accelerate the calculation of the algorithm further.Experimental research was conducted on the high-performance FT-M7002 DSP platform in this paper.The results show that,compared with the running performance of the LMS adaptive filtering algorithm in Texas Instruments(TI)’s dsplib library on the TMS320C6678 processor,the optimization effect of the proposed optimization algorithm in this paper can achieve a maximum speed-up ratio of up to 6.9×for medium-scale data.The merged memory access optimization implemented on the GPU platform achieves an average 1.5x speedup compared to the basic parallel scheme.展开更多
A new type of vocoder system based upon formant analysis is presented in this paper. The LMS adaptive algorithm is used for tracking formants of speech signals. The results of computer simulation show that the new voc...A new type of vocoder system based upon formant analysis is presented in this paper. The LMS adaptive algorithm is used for tracking formants of speech signals. The results of computer simulation show that the new vocoder has better synthesized speech quality.展开更多
This paper presents an algorithm that can adaptively select the intermediate frequency（IF） and compensate the IQ mismatch according to the power ratio of the adjacent channel interference to the desired signal in a ...This paper presents an algorithm that can adaptively select the intermediate frequency（IF） and compensate the IQ mismatch according to the power ratio of the adjacent channel interference to the desired signal in a low-IF GSM receiver.The IF can be adaptively selected between 100 and 130 kHz.Test result shows an improvement of phase error from 6.78°to 3.23°.Also a least mean squares（LMS） based IQ mismatch compensation algorithm is applied to improve image rejection ratio（IRR） for the desired signal along with strong adjacent channel interference.The IRR is improved from 29.1 to 44.3 dB in measurement.The design is verified in a low-IF GSM receiver fabricated in SMIC 0.13μm RF CMOS process with a working voltage of 1.2 V.展开更多
基金Supported by the National Natural Science Foundation of China （No. 60532030）.
文摘Based on the good time-frequency localization of the wavelet packet modulation （WPM） system and the analysis of the muhitone （MT） interference, an improved WPM narrow band interference （NBI） rejection system using an adaptive least mean square （LMS） algorithm is discussed in this paper. In the WPM interference rejection system, according to the structure of the wavelet packet tree （WFF） and the characteristic of the MT interference, the demodulated WPM signal which contains the interference component is filtered using an adaptive LMS filtering implementation. Theoretical analysis and simulation resuits show that the proposed method improves the bit error rate （BER） performance of the WPM system in the presence of MT interference.
基金funded by the Hunan Provincial Natural Science Foundation of China(No.2023JJ50019)the National Science and Technology Major Project(No.2022ZD0119003).
文摘The Least Mean Square(LMS)adaptive filtering algorithm is a significant filtering algorithm widely used in noise processing and other fields that automatically adjusts the values of filter coefficients according to the results,aimed at optimizing the filtered results.Based on a basic serial LMS adaptive filtering algorithm,we propose a vectorized parallel processing scheme for the LMS adaptive filtering algorithm in this work.By combining the characteristics of the algorithm processing flow and those of the parallel technologies used in vector Digital Signal Processes(DSPs),the optimizations such as loop fusion,double-word accessing,and vector shuffling of the LMS algorithm are studied in depth,and the loop unrolling optimization method is used to accelerate the calculation of the algorithm further.Experimental research was conducted on the high-performance FT-M7002 DSP platform in this paper.The results show that,compared with the running performance of the LMS adaptive filtering algorithm in Texas Instruments(TI)’s dsplib library on the TMS320C6678 processor,the optimization effect of the proposed optimization algorithm in this paper can achieve a maximum speed-up ratio of up to 6.9×for medium-scale data.The merged memory access optimization implemented on the GPU platform achieves an average 1.5x speedup compared to the basic parallel scheme.
文摘A new type of vocoder system based upon formant analysis is presented in this paper. The LMS adaptive algorithm is used for tracking formants of speech signals. The results of computer simulation show that the new vocoder has better synthesized speech quality.
基金supported by the Important National Science and Technology Specific Projects of China(No.2009ZX01031-003-002)the National High Technology Research and Development Program of China(No.2009AA011605)the National Natural Science Foundation of China(No.61076028)
文摘This paper presents an algorithm that can adaptively select the intermediate frequency（IF） and compensate the IQ mismatch according to the power ratio of the adjacent channel interference to the desired signal in a low-IF GSM receiver.The IF can be adaptively selected between 100 and 130 kHz.Test result shows an improvement of phase error from 6.78°to 3.23°.Also a least mean squares（LMS） based IQ mismatch compensation algorithm is applied to improve image rejection ratio（IRR） for the desired signal along with strong adjacent channel interference.The IRR is improved from 29.1 to 44.3 dB in measurement.The design is verified in a low-IF GSM receiver fabricated in SMIC 0.13μm RF CMOS process with a working voltage of 1.2 V.
