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The present invention provides several apparatus, methods, and computer program products for establishing a data communication link between an interrogation device and the data bus of a vehicle. Specifically, in one embodiment, the present invention provides apparatus, methods, and computer program

The present invention provides several apparatus, methods, and computer program products for establishing a data communication link between an interrogation device and the data bus of a vehicle. Specifically, in one embodiment, the present invention provides apparatus, methods, and computer program products that process data transmitted to and from the data bus of a vehicle one bit at a time with minimal delay. The apparatus, methods, and computer program products of this embodiment also prevent propagation of false data to both the data bus and the interrogation device, which is generated by the transmission of data to and from the data bus. The present invention also provides apparatus and methods that reduce the introduction of false data in the form of signal noise onto the data bus of a vehicle when the data bus is not transmitting data to or receiving data from a remote location. In this embodiment, the present invention includes a switch, that in the open position isolates the data bus from a transceiver used to receive external data. The present invention also provides apparatus and methods that establish data communication links between interrogation devices and the data bus of a vehicle by transmitting a data link command alerting the data bus that the interrogation device is attempting to form a data communication link. In some embodiments, both the vehicle and remote interrogation device transmit a heartbeat signal to each other over a data communication link to signify that a data communication link is present. When the heartbeats signal is not received, the vehicle and interrogation device determine that the data link has ended.

대표청구항 ▼

The present invention provides several apparatus, methods, and computer program products for establishing a data communication link between an interrogation device and the data bus of a vehicle. Specifically, in one embodiment, the present invention provides apparatus, methods, and computer program

The present invention provides several apparatus, methods, and computer program products for establishing a data communication link between an interrogation device and the data bus of a vehicle. Specifically, in one embodiment, the present invention provides apparatus, methods, and computer program products that process data transmitted to and from the data bus of a vehicle one bit at a time with minimal delay. The apparatus, methods, and computer program products of this embodiment also prevent propagation of false data to both the data bus and the interrogation device, which is generated by the transmission of data to and from the data bus. The present invention also provides apparatus and methods that reduce the introduction of false data in the form of signal noise onto the data bus of a vehicle when the data bus is not transmitting data to or receiving data from a remote location. In this embodiment, the present invention includes a switch, that in the open position isolates the data bus from a transceiver used to receive external data. The present invention also provides apparatus and methods that establish data communication links between interrogation devices and the data bus of a vehicle by transmitting a data link command alerting the data bus that the interrogation device is attempting to form a data communication link. In some embodiments, both the vehicle and remote interrogation device transmit a heartbeat signal to each other over a data communication link to signify that a data communication link is present. When the heartbeats signal is not received, the vehicle and interrogation device determine that the data link has ended. first and second tristate buffers, respectively. These tristate buffers are supplied at their respective input terminals with a high potential driving pulse signal corresponding to information data at shifted timings to generate a ternary transmission pulse signal on the balanced transmission lines. information signal and that provides a corresponding trace back soft decision signal; at least one spread spectrum code function correlator for decoding said trace back soft decision signal according to a predetermined spreading code sequence; a carrier loop circuit for phase and frequency tracking the information signal; a chip decision circuit operative with the carrier tracking loop for tracking high rate chips; a decision feedback equalizer formed from a finite impulse response filter operative with the chip decision circuit and carrier loop circuit, and having a plurality of feedback taps, wherein at least one feedback tap is selected for logical add/subtract operations for equalizing a post-cursor portion of the information signal; and a modulator for spread spectrum PSK modulating information for transmission via the radio circuit, said modulator comprising at least one code function encoder for encoding information according to an orthogonal code sequence. 12. A spread spectrum radio transceiver according to claim 11, wherein said at least one spread spectrum code function correlator comprises a Walsh correlator. 13. A spread spectrum radio transceiver according to claim 11, wherein said Viterbi decoder further comprises means for generating said trace back soft decision signal to the spread spectrum code function correlator. 14. A spread spectrum radio transceiver according to claim 11, wherein said Viterbi decoder further comprises means for generating a partial trace back signal to predetermined feedback taps of said finite impulse response filter. 15. A spread spectrum radio transceiver according to claim 11, wherein said carrier loop circuit comprises: a carrier numerically controlled oscillator (NCO); and a carrier NCO control means for selectively operating the carrier NCO based upon a carrier phase on the carrier tracking loop. 16. A spread spectrum radio transceiver comprising: a baseband processor and a radio circuit connected thereto, said baseband processor comprising a demodulator for spread spectrum phase shift keying (PSK) demodulating an information signal on a signal channel, wherein said information signal includes data symbols formed from a plurality of high rate mode chips forming a spread spectrum information signal, said demodulator comprising, a Viterbi decoder that receives the information signal and decodes a precursor portion thereof, and generates a traceback soft decision signal; at least one said spread spectrum code function correlator for decoding said traceback soft decision signal of the information signal according to a predetermined spreading code sequence; a decision feedback equalizer operative with said Viterbi decoder for equalizing a post-cursor portion of the information signal; and a modulator for spread spectrum PSK modulating information for transmission via the radio circuit, said modulator comprising at least one code function encoder for encoding information according to a spreading code sequence. 17. A spread spectrum radio transceiver according to claim 16, wherein said at least one spread spectrum code function correlator comprises a Walsh correlator. 18. A demodulator for a spread spectrum radio transceiver, said demodulator comprising: a demodulator circuit for spread spectrum phase shift keying (PSK) demodulating an information signal on a signal channel, wherein said information signal includes data symbols formed from a plurality of high rate mode chips forming a spread spectrum information signal, said demodulator comprising a Viterbi decoder that receives the information signal and decodes a precursor portion of the information signal; at least one spread spectrum code function correlator for decoding said precursor portion of the information signal according to a predetermined spreading code sequence; a carrier loop circuit for phase and frequency tracking the information signal; a chip decision circuit operative with the ca rrier loop circuit for tracking high rate chips; a decision feedback equalizer formed from a finite impulse response filter operative with the chip decision circuit and carrier loop circuit, and having a plurality of feedback taps, wherein at least one feedback tap is selected for logical add/subtract operations for equalizing a post-cursor portion of the information signal. 19. A demodulator according to claim 18, wherein said at least one spread spectrum code function correlator comprises a Walsh correlator. 20. A demodulator according to claim 18, wherein decoding said precursor portion of the information signal further comprises means for generating a trace back soft decision signal to the spread spectrum code function correlator. 21. A demodulator according to claim 18, wherein said Viterbi decoder further comprises means for generating a partial trace back signal to predetermined feedback taps of said finite impulse response filter. 22. A demodulator according to claim 18, wherein said carrier loop circuit comprises: a carrier numerically controlled oscillator (NCO); and a carrier NCO control means for selectively operating the carrier NCO based upon a carrier phase on the carrier tracking loop. 23. A demodulator for a spread spectrum radio transceiver, said demodulator comprising: a demodulator circuit for spread spectrum phase shift keying (PSK) demodulating an information signal on a signal channel, wherein said information signal includes data symbols formed from a plurality of high rate mode chips forming a spread spectrum information signal, said demodulator comprising a Viterbi decoder that receives the information signal and decodes a precursor portion of the information signal and generates a traceback soft decision signal; at least one spread spectrum code function correlator for decoding said traceback soft decision signal according to a predetermined spreading code sequence; a decision feedback equalizer operative with said Viterbi decoder for equalizing a post-cursor portion of the signal channel. 24. A demodulator according to claim 23, wherein said at least one spread spectrum code function correlator comprises a Walsh correlator. e at least the second sequence of the modulator output signals is applied to the at least the second antenna transducer. 4. The apparatus of claim 1 wherein each of the at least first sequence of modulator output symbols formed by said mapper is formed of a first plurality of symbols. 5. The apparatus of claim 4 wherein the at least the first sequence comprises a plurality of sequences, each formed of the first plurality of symbols, the plurality of sequences arranged to form columns of a code matrix, individual ones of the symbols of the first plurality of symbols of which each of the plurality of sequences is formed defining rows of the code matrix, and wherein the codeword is formed of successive rows of the code matrix concatenated together. 6. The apparatus of claim 5 wherein the arbitrary pair of codewords of which the difference matrix is formed comprises a first codeword formed responsive to a first group of encoder output symbols applied to said mapper and a second codeword formed responsive to a second group of encoder output symbols applied to said mapper. 7. The apparatus of claim 5 wherein the difference matrix is formed of a plurality of submatrices, each submatrix formed by a Radon-Hurwitz construction. 8. The apparatus of claim 7 wherein each Radon-Hurwitz construction is formed of a square Radon-Hurwitz construction. 9. The apparatus of claim 8 wherein each square Radon-Hurwitz construction is formed of a two-by-two submatrix. 10. In the radio communication system of claim 1, a further improvement of apparatus for the receiving station of an estimator for estimating, responsive to reception at the receiving station of a signal representative of the at least the first sequence of modulator output signals, values of the first sequence of modulator output symbols, estimates formed by said estimator by distance metric calculations. 11. In a method for communicating data in a communication system between a sending station and a receiving station connected by way of a communication channel susceptible to fading, an improvement of a method for modulating a group of encoder output symbols, the group of encoder output symbols encoded representations of the data to be communicated upon the communication channel, said method comprising: mapping the group of encoder output symbols to at least a first sequence of modulator output symbols, the at least first sequence of the modulator output symbols formed of at least one symbol and the at least first sequence forming a codeword such that a Hermitian of a difference matrix formed between an arbitrary number of codewords multiplied by the difference matrix forms a diagonal product matrix having a diagonal with all diagonal elements of the diagonal equal to each other. 12. The method of claim 11 wherein the sending station comprises at least a first antenna transducer and wherein said method comprises the additional operation of applying the at least the first sequence of modulator output symbols to the at least the first antenna transducer to be transduced therefrom. 13. The method of claim 12 wherein the at least the first antenna transducer comprises the first antenna transducer and at least a second antenna transducer, wherein the at least the first sequence of modulator output symbols comprises the first sequence of the modulator output symbols and at least a second sequence of the modulator output symbols, and wherein said operation of applying comprises applying the first sequence of the modulator output symbols to the first antenna transducer and applying the at least second sequence of the modulator output symbols to the at least the second antenna transducer. 14. The method of claim 11 wherein each of the at least first sequence of the modulator output symbols formed during said operation of mapping is formed of a first plurality of symbols. 15. The method of claim 14 wherein the at least the first sequence of modulator output symbols formed during said operatio