Topcon Positioning Systems, Inc.

Dmitry D Murzinov

Andrey Vladimirovich Veitsel

Victor Andreevich Prasolov

Timur G Kelin

Dmitry A Pyatkov

Igor Anatolyevich Orlovsky

System for digital sweep type spectrum analysis with up/down frequency provides measurements of frequency spectrum of complex analog baseband input signal. The signal is quantized into three levels with fs based on the bandwidth of the input signal. Four multiplexers, a first block of registers and a block of adders perform operations equivalent to complex multiplication of the quadrature components. Two complex signals with up and down shifted spectrum are produced by the adders. The quadrature components are inputted to the accumulators with reset, which act as low-pass filters and accumulate several samples at a constant frequency fof the local oscillator. Levels of two accumulated complex samples are estimates of input signal spectrum in two frequency points +fand &#x2212;f. A sweep controller changes a frequency of the local oscillator from zero up to fs/2. Estimates of the input signal spectrum are generated sequentially in range &#x2212;fs/2 to +fs/2.

Digital sweep type spectrum analyzer with up/down frequency conversion

A digital filter for narrowband interference rejection, including modules of narrowband interference rejection connected in series, each of which includes the following elements connected in series: a block of successive vector rotation based on the CORDIC vector rotation algorithm for integers, a block of reduction of the length of the rotated vector to maintain the same number of bits for digital signal representation, a block of high-pass filters for orthogonal components of the reduced vector in order to remove the interference from zero frequency region. The filter can be implemented without multiplication.

Digital filter for narrowband interference rejection

A multi-channel sequential Viterbi decoder includes: an input buffer, a 'Read Data from Input Buffer' signal driver, a processing unit selector, a decoder channel parameters registers unit, a processing unit for a 'Reset Path Metrics' command, a processing unit for a &#x201c;Set Path Metric Value for the Given Path Number&#x201d; command, a processing unit for a &#x201c;Get Single Bit from the Path with Given Number&#x201d; command, a processing unit for a &#x201c;Process Input Samples&#x201d; command, a memory for storing decoding paths and path metrics, a unit for generating an address for the memory, and data buffers for decoder channels output.

Multi-channel sequential Viterbi decoder

A multi-channel sequential Viterbi decoder includes: an input data buffer, a 'Read Single Data Word from Input Data Buffer' signal driver, a processing unit selector, a decoder channel parameters registers unit, a processing unit for the 'Reset Path Metrics' command, a processing unit for the &#x201c;Set Path Metric Value for the Given Path Number&#x201d; command, a processing unit for the &#x201c;Get Single Bit from the Path with Given Number&#x201d; command, a processing unit for the &#x201c;Process Input Samples&#x201d; command, a decoding paths and path metrics RAM, a unit for generating current decoder channel base address for the decoding paths and path metrics RAM, a unit for generating cell address for the decoding path and path metric RAM, and a data buffers unit for decoder channels output.

Growing community of inventors

Moscow, Russia

Dmitry D Murzinov