Abstract: A surface treatment process for a metal article includes the following steps. Firstly, a metal article is provided. Secondly, the metal article is anodized to form an anodic oxide layer on a surface thereof. Thirdly, the surface of the metal article is rinsed. Fourthly, the surface of the metal article is dyed. Fifthly, the now-dyed anodic oxide layer of the metal article is sealed. Finally, the metal article is rinsed using an acetic acid solution.

Abstract: A surface treatment process for a welded metal article includes following steps. Firstly, a metal article with a weld joint region is provided. Secondly, the metal article is anodized to form an anodic oxide layer on a surface thereof. Thirdly, the surface of the anodized metal article is rinsed. Fourthly, at least the anodized surface of the metal article in the region of the weld joint region is activated in a nitric acid solution. Fifthly, the anodized surface (i.e., the anodic oxide layer) of the metal article is dyed. Sixthly, the anodic oxide layer of the metal article is sealed. Finally, the metal article is rinsed.

Abstract: System and method for analyzing communication signals. A digital signal comprising multiple samples is received, representing a plurality of binary symbols. Zero crossings of the signal are determined, each comprising a respective first sample immediately preceding the zero crossing and a respective second sample immediately following the zero crossing. Per zero crossing, an error expression is determined interpolating between the first and second samples as a function of estimated period T and estimated offset ? of the signal. Based on the error expressions, values of T and ? are determined using a linear fit that minimizes a total error of values of the error expressions. T and ? are usable in analyzing the signal, e.g., each zero crossing corresponds to a respective symbol represented by a respective segment of the signal. The segments are overlaid based on T and ?, forming an eye diagram usable to analyze the signal.

Abstract: A system and method for estimating parameters of multiple tones in an input signal. The method includes receiving samples of the input signal, generating a frequency transform (FT) of the samples, identifying multiple amplitude peaks in the FT corresponding to the tones, and determining parameter estimates characterizing each of the multiple tones based on the peaks. For each tone, the effects of the other tones are removed from the FT of the peak of the tone using the parameter estimates of the other tones to generate modified FT data for the tone. Single tone estimation is applied to the modified FT data to generating refined parameter estimates of the tone, which is used to update the parameter estimates of the tone. After refining the estimates for each tone, the entire process may be repeated one or more times using successive refined estimates to generate final estimates for the parameters.

Abstract: System and method for estimating signal parameters (e.g., frequency, amplitude and/or phase) of one or more tones present in an input signal. Samples of the input signal are received, and a frequency transform of the samples generated. An amplitude peak in the frequency transform corresponding to the tone is identified. Two or more frequency bins are selected proximate to the identified frequency in the transform. A tone frequency value is determined that minimizes a difference between two or more expressions, each including respective numerator and denominator terms corresponding to respective frequency bins and whose ratios each represent a complex amplitude of the tone at a respective bin. Each expressions includes a tone frequency variable that represents a correct tone frequency value of the tone.

Abstract: A system and method for estimating parameters of multiple tones in an input signal. The method includes receiving samples of the input signal, generating a frequency transform (FT) of the samples, identifying multiple amplitude peaks in the FT corresponding to the tones, and determining parameter estimates characterizing each of the multiple tones based on the peaks. For each tone, the effects of the other tones are removed from the FT of the peak of the tone using the parameter estimates of the other tones to generate modified FT data for the tone. Single tone estimation is applied to the modified FT data to generating refined parameter estimates of the tone, which is used to update the parameter estimates of the tone. After refining the estimates for each tone, the entire process may be repeated one or more times using successive refined estimates to generate final estimates for the parameters.

Abstract: System and method for analyzing communication signals. A digital signal comprising multiple samples is received, representing a plurality of binary symbols. Zero crossings of the signal are determined, each comprising a respective first sample immediately preceding the zero crossing and a respective second sample immediately following the zero crossing. Per zero crossing, an error expression is determined interpolating between the first and second samples as a function of estimated period T and estimated offset &tgr; of the signal. Based on the error expressions, values of T and &tgr; are determined using a linear fit that minimizes a total error of values of the error expressions. T and &tgr; are usable in analyzing the signal, e.g., each zero crossing corresponds to a respective symbol represented by a respective segment of the signal. The segments are overlaid based on T and &tgr;, forming an eye diagram usable to analyze the signal.

Abstract: A system and method for estimating parameters of multiple tones in an input signal. The method includes receiving samples of the input signal, generating a frequency transform (FT) of the samples, identifying multiple amplitude peaks in the FT corresponding to the tones, and determining parameter estimates characterizing each of the multiple tones based on the peaks. For each tone, the effects of the other tones are removed from the FT of the peak of the tone using the parameter estimates of the other tones to generate modified FT data for the tone. Single tone estimation is applied to the modified FT data to generating refined parameter estimates of the tone, which is used to update the parameter estimates of the tone. After refining the estimates for each tone, the entire process may be repeated one or more times using successive refined estimates to generate final estimates for the parameters.

Abstract: A system and method for estimating parameters of multiple tones in an input signal. The method includes receiving samples of the input signal, generating a frequency transform (FT) of the samples, identifying multiple amplitude peaks in the FT corresponding to the tones, and determining parameter estimates characterizing each of the multiple tones based on the peaks. For each tone, the effects of the other tones are removed from the FT of the peak of the tone using the parameter estimates of the other tones to generate modified FT data for the tone. Single tone estimation is applied to the modified FT data to generating refined parameter estimates of the tone, which is used to update the parameter estimates of the tone. After refining the estimates for each tone, the entire process may be repeated one or more times using successive refined estimates to generate final estimates for the parameters.

Abstract: A system and method for estimating signal parameters (e.g., one or more of frequency, amplitude and/or phase) of one or more tones present in an input signal. The method may comprise first receiving samples of the input signal, wherein the input signal includes the tone, and generating a frequency transform of the samples. The method may then identify an amplitude peak in the frequency transform corresponding to the tone. Two or more frequency bins may then be selected proximate to the identified frequency location in the frequency transform. The method may then determine a tone frequency value that minimizes a difference between two or more expressions. The expressions include numerator and denominator terms that correspond to respective frequency bins, wherein a ratio of each numerator term and its corresponding denominator term represent a complex amplitude of the tone at a respective bin.

Abstract: A code division multiple access time division duplex communication system having an adaptive antenna array station communicates beamformed orthogonal code channels to a remote station. The remote station determines the amplitude and phase components of the received code channels and communicates the information back to the adaptive antenna array station which uses the information plus the beamform of the received signal in an adaptive antenna array station calibration process. By varying one of the beamforms received by the remote station, sufficient data points may be gathered to facilitate accurate calibration. The calibration procedure may be performed while voice or other digital information is communicated between the remote station and the adaptive antenna array station.

Abstract: A code division multiple access time division duplex communication system having an adaptive antenna array station communicates beamformed orthogonal code channels to a remote station. The remote station determines the amplitude and phase components of the received code channels and communicates the information back to the adaptive antenna array station which uses the information plus the beamform of the received signal in an adaptive antenna array station calibration process. By varying one of the beamforms received by the remote station, sufficient data points may be gathered to facilitate accurate calibration. The calibration procedure may be performed while voice or other digital information is communicated between the remote station and the adaptive antenna array station.