Harold P Stern

US Patent:

50900269, Feb 18, 1992

Filed:

Sep 11, 1989

Appl. No.:

7/405423

Inventors:

Harold P. Stern - Arlington TX
Mohammed S. El-Tanany - Quebec, CA

Assignee:

ElectroCom Automation, Inc. - Arlington TX

International Classification:

H04L 2712
H04L 2714

US Classification:

375 47

Abstract:

A GMSK modem is provided and comprises a baseband modulator section and demodulator section coupled to an FM transmitter and receiver, respectively. The Modulator section includes a digital waveform generator for generating a GMSK baseband signal from a binary digital data source. The output of the waveform generator approximates the baseband signal output of a premodulation filter with a Gaussian impulse response having a normalized noise bandwidth of between 0. 25 and 0. 45 in series with a gain controlled amplifer. The gain is adjusted such that the modulation index of an RF signal modulated with the baseband signal is between 0. 5 and 0. 7. The demodulator section receives the analog output of a discriminator-based FM receiver with a phase equalized Butterworth IF filter. The demodulator section comprises a binary quantized loop bit timing recovery subsystem and one or the other of two data detectors. The two data detectors comprise a two-bit integrate-and-dump type filter and a two-bit multithreshold integrate-and-dump type filter.

US Patent:

20210064831, Mar 4, 2021

Filed:

Jan 28, 2019

Appl. No.:

16/963638

Inventors:

- San Marcos TX, US
Harold Stern - San Marcos TX, US

International Classification:

G06K 7/10
G06K 19/07

Abstract:

A method, system and computer program product for enabling early collision detection and handling in Code Division Multiple Access (CDMA)-based radio-frequency identification (RFID) systems. A tag receives an instruction from a reader to reflect either a single encoded bit or multiple encoded bits. The tag then reflects either the single encoded bit or the multiple encoded bits to the reader. The reader decodes the received encoded bit(s) from the tag, where the decoded bit(s) are placed in a vector or matrix by the reader. The vector/matrix is then transmitted to the tag, which determines if the reflected bit(s) agree with the corresponding bit(s) in the vector/matrix thereby indicating whether the reflected bit(s) were read successfully by the reader. The tag will then enter a no reflection mode in response to a disagreement between the reflected bit(s) with the corresponding bit(s) in the vector/matrix thereby preventing collisions from occurring.