Abstract: A synchronization system for initial setup of phases of local oscillators in a wireless receiver of a communication system characterized by transmission of data packets having a predetermined preamble consisting of M identical sections of L symbols followed by a single section of the same kind, multiplied by ?1, and wherein the wireless receiver is operative to perform decimation in an RF demodulator. The synchronization system includes a twofold correlator, an accumulator, a multipler, a threshold comparator, a carrier phase former and a clock phase former, and operates at a decimated symbols frequency, and performs not only preamble detection, but also symbols clock phase detection together with carrier phase detection, while enabling the theoretically possible noise immunity.

Abstract: A vector signal generator with direct RF signal synthesis is disclosed. The vector signal generator comprises an RF signal synthesizer, a switch, and a memory. The RF signal synthesizer is configured for converting baseband IQ signals into a modulated digital RF signal. The RF signal synthesizer is connected to an I input, a Q input, a clock input, a control input, and an output, where the clock input is a clock input of the vector signal generator, the control input is a control input of the vector signal generator, and the output is an RF signal output of the vector signal generator. The switch is configured for selecting a source of IQ signals and is connected to an external I input, an external Q input, a stored signal I input, a stored signal Q input, the control input, an I output, and a Q output. The external I input and external Q input are external IQ inputs to the vector signal generator and the I output and the Q output are connected to the I input and the Q input of the RF signal synthesizer.

Abstract: Disclosed is a method of equalization of a vector/signal analyzer including: providing a structured test signal within a selected frequency range. The structured test signal includes a plurality of frequency components each having a respective amplitude and phase. The method includes inputting the test signal to the analyzer; the analyzer operating to condition the test signal; determining information representative of frequency distortion of the conditioned test signal introduced by the analyzer; generating a set of equalization coefficients based on the information representative of the frequency distortion, the set of coefficients corresponding to the selected frequency range; and storing the set of equalization coefficients and the correspondence of the set of coefficients to the selected frequency range.

Abstract: Disclosed is a method of measuring frequency distortions characteristics of a device under test, the device configured convert an input signal in an input frequency range to an output signal in a different output frequency range. The method includes, for each test frequency fi, where i=1, . . . , N and N a positive integer, in a selected frequency range, providing a corresponding test signal with multiple frequency components having a measurement component with a frequency fi, a first reference component with a frequency fA, and a second reference component with a frequency fB; inputting the test signals into the device under test; measuring output test signals at the output of the device under test corresponding to the input test signals; and determining, for each test frequency fi, information representative of frequency distortions based on the corresponding input test signal and the corresponding output test signal.

Abstract: Disclosed is a method of equalization of a vector/signal analyzer including: providing a structured test signal within a selected frequency range, the structured test signal comprising a plurality of frequency components each having a respective amplitude and phase; inputting the test signal to the analyzer; the analyzer operating to condition the test signal; determining information representative of frequency distortion of the conditioned test signal introduced by the analyzer; generating a set of equalization coefficients based on the information representative of the frequency distortion, the set of coefficients corresponding to the selected frequency range; and storing the set of equalization coefficients and the correspondence of the set of coefficients to the selected frequency range.

Abstract: Disclosed is a method of measuring frequency distortions characteristics of a device under test, said device configured convert an input signal in an input frequency range to an output signal in a different output frequency range. The method includes, for each test frequency fi, where i=1, . . . ,N and N a positive integer, in a selected frequency range, providing a corresponding test signal with multiple frequency components comprising a measurement component with a frequency fi, a first reference component with a frequency fA, and a second reference component with a frequency fB; inputting said test signals into the device under test; measuring output test signals at the output of the device under test corresponding to the input test signals; and determining, for each test frequency fi, information representative of frequency distortions based on the corresponding input test signal and the corresponding output test signal.

Abstract: Analysis of a read back signal in a magnetic recording device is disclosed. The read back signal is converted to a digital read back signal, and a low frequency component of the digital read back signal is restored. A sample clock is recovered from the restored digital read back signal, and the restored digital read back signal is averaged using the recovered sample clock. A timing error is calculated based at least in part on the averaged restored digital read back signal.

Abstract: A decoder for detecting data within an input signal with attenuated low frequency components that comprises a Viterbi decoder, is disclosed. Viterbi decoder internal data is used along with its output bits to reduce delay between the restored direct current (DC) component and the input signal to zero. As a result, increased accuracy of DC restoration and corresponding bit error rate reduction are achieved.

Abstract: A partial response maximum likelihood (PRML) data detecting in a magnetic recording storage device is carried out with a preliminary measuring of write-read channel responses to all nonzero binary combinations of a given length. Decoding of the user data is performed according to a Viterbi algorithm, where the previously measured responses are used as expected samples for branch metric calculations. The measurement of the write-read channel responses and the decoding of the user data are fulfilled by a self-adjusting PRML receiver that contains a controllable clock recovery, a responses accumulator and an adjustable Viterbi detector. The controllable clock recovery produces a set of read-back signal samples containing exactly one sample per bit with or without phase error correction. The responses accumulator calculates averaged responses of the write-read channel. The adjustable Viterbi detector reconstructs the user data that were written to the disk.