Abstract: The present invention provides a system and method for radio communications wherein the transmitted signals include an intermediate frequency in addition to a carrier frequency to aid in demodulation of data modulated on the signals and regulate the local oscillator frequency at the receiver. The invention greatly reduces the number of components required to implement a radio, and in particular, a direct sequence spread spectrum radio, reduces the frequency stability requirement at the transmitting and receiving ends of the communication, automatically tracks changes in the transmission signal after transmission, and permits the use of a single frequency reference to provide all required frequencies to operate both the receiver and the transmitter in each radio.

Abstract: The present invention provides a system and method for radio communications wherein the transmitted signals include an intermediate frequency in addition to a carrier frequency to aid in demodulation of data modulated on the signals and regulate the local oscillator frequency at the receiver. The invention greatly reduces the number of components required to implement a radio, and in particular, a direct sequence spread spectrum radio, reduces the frequency stability requirement at the transmitting and receiving ends of the communication, automatically tracks changes in the transmission signal after transmission, and permits the use of a single frequency reference to provide all required frequencies to operate both the receiver and the transmitter in each radio.

Abstract: The invention provides a volatile or non-volatile memory and a latching circuit wherein data held in a first memory location is used to address the next memory location, in addition to providing a synchronous portion of the code. Accordingly, the data at the next memory address is used as a succeeding address and a subsequent portion of the code. The data is organized to repeat when the data stored in the address location is equal to the starting address.

Abstract: The present invention provides a system and method for radio communications wherein the transmitted signals include an intermediate frequency in addition to a carrier frequency to aid in demodulation of data modulated on the signals and regulate the local oscillator frequency at the receiver. The invention greatly reduces the number of components required to implement a radio, and in particular, a direct sequence spread spectrum radio, reduces the frequency stability requirement at the transmitting and receiving ends of the communication, automatically tracks changes in the transmission signal after transmission, and permits the use of a single frequency reference to provide all required frequencies to operate both the receiver and the transmitter in each radio.

Abstract: The invention provides a read-only memory and a latching circuit wherein data held in a first memory location is used to address the next memory location, in addition to providing a synchronous portion of the code. Accordingly, the data at the next memory address is used as a succeeding address and a subsequent portion of the code. The data is organized to repeat when the data stored in the address location is equal to the starting address.

Abstract: A portable optical data reader for optically sensing and decoding data, comprising a carrier oscillator for producing a carrier signal at a predetermined frequency, an optical emitter electrically connected to the carrier oscillator for emitting optical radiation in an optical path to an optical data carrier at the predetermined frequency, an optical detector for detecting the emitted optical radiation returning from the optical data carrier thereby receiving the optical data and producing a detected electrical signal responsive thereto, and a double balanced demodulator electrically connected to the optical detector and the carrier oscillator for combining the detected radiation signal with the carrier signal to demodulate the optical data with the optical data carrier.

Abstract: A communication system for simultaneous exchange of signals between first and second stations in which a timing signal of low frequency alternately switches a first station between receive and transmit with equal time periods and simultaneously switches a second station between transmit and receive with the same time periods. During a receive period, signals for transmission are delayed until the next transmit period. During the transmit period, the delay signal is combined with the signal occupying the transmit period. The combined signal along with the timing signal is transmitted by the first station to the second station, after which the first radio station switches to receive under control of the timing signal. The second station under the control of the same timing signal now transmits a similar combined signal which is received by the first station for processing.