Abstract: An automotive radar system for use with an automotive control system such as a collision avoidance or smart cruise control system, for example. A wide-bandwidth, random noise signal generated at an RF frequency that is transmitted by a transmitter and reflected from targets in the vicinity of the system. The random noise modulation is sampled prior to transmission in a noise source sampler and this sampled image of the transmitted noise is stored and passed through a series of delay stages that are formed in a correlator. The noise signal reflected from objects is processed by a homodyne receiver and also sampled in a receiver sampler. The noise samples from the signal return are passed to the correlator where they are cross correlated with the delayed images of the transmit noise. The output from the correlator for each unit of delay (range gate) is processed in a digital signal processor to find the range and closing velocity (Doppler frequency) of objects in the field of view.

Abstract: A videocassette security box includes a base with a protective cover pivotally attached thereto and adapted to contain videocassettes. A key-hole orifice through the base allows mounting of the base over a doorknob or other suitable mounting member whereafter the narrower portion of the key-hole is moved behind the doorknob. Closing of the cover blocks across to the larger portion of the key-hole to preclude removal of the box from the doorknob as long as the cover remains closed while a lock mechanism allows securing of the cover in the closed position.

Abstract: An apparatus is disclosed for a cellular mobile communication system utilizing a spread spectrum. A plurality of fixed base stations is connected with a central processor so that calls originating in any cell can terminate in any other cell. The available frequency spectrum is divided such that one-half is used for mobile-to-base station transmission and the other one-half is used for base station-to-mobile unit transmission. A power control/mobile locator system and method is utilized in all mobile units to compensate for changes in signal level and to maintain the average received signal level at the base station constant regardless of the location of the mobile unit within the cell. In addition, each mobile unit has a unique set of time-frequency coded waveforms that are used for both transmission and reception.

Abstract: A method is disclosed for signal transmission and reception utilizing wideband signals, and, more particularly, the use of time-frequency coded signals to achieve more efficient use of the electromagnetic spectrum. The method can be generally utilized for signal transmission and reception, including personal communication uses such as utilized for land-mobile radio communications. Each user is assigned a unique set of time-frequency coded waveforms for both transmission and reception, and both message and control signals are transmitted and received using the assigned unique set of signals. Message modulation is effected by digitizing the message, such as a speech message, and several types of message digitization, including PCM are set forth. For land-mobile radio service, the geographical area is divided into a series of cells each of which has a base station therein for communication with the mobile units then in the cell.

Abstract: A demodulator unit is disclosed for spread spectrum apparatus utilized in a cellular mobile communication system. The cellular mobile communication system includes a plurality of fixed base stations connected with a central processor so that calls originating in any cell can terminate in any other cell. Each mobile unit has a unique set of time-frequency coded waveforms that are used for both transmission and reception. Message modulation is accomplished by digitizing the speech and encoding the resulting binary sequences into the set of waveforms available to the user, while detection is accomplished by the demodulator unit in which the phases of each received waveform are compared with those of the preceding waveform. The demodulator unit includes a tapped delay line which can have mixers before and after the delay line and can be a narrowband unit with delays and mixers.

Abstract: A random signal flaw detection system is disclosed that provides enhanced system sensitivity and/or increased range capabilities as well as being capable of improved resolution where necessary or desired. The system includes a generator which produces random electrical signals which are converted at a transducer into ultrasound for transmission into a test object. The reflected signal is received at a transducer and converted to an electrical signal which is then correlated with a delayed sample of the transmitted signal with the output being indicative of the sensed flaws in the test object.

Abstract: A doppler effect flow measurement device using ultrasonic stationary random noise whereby errors and inaccuracies common in existing doppler flow measurement systems are overcome.