JPH07509592A - Spread spectrum communication system suitable for RF network communication - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 9. The invention according to claim 8, wherein the modulated carrier transmitted within the channel The rear signal has two nodes approximately equidistant from each other on the upper and lower blades with respect to the carrier signal. the passband is sufficient to decode the signal. An invention characterized by including an amount of information.

10. The invention according to claim 3, wherein the carrier signal is connected to the direct sequence. Therefore! - The invention is characterized in that it is modulated.

11. The invention according to claim 3, wherein the modulated carrier signal has an RF frequency shift. An invention characterized by being in the area of

12. At least two methods of transmitting data through a communication channel A series of digital signals having possible values are transmitted by said communication channel. the step of receiving the Generate at least two different directional sequences each consisting of multiple chips step and the digital signal for representing different values of the digital signal using the directional sequence; a step of coding the digital signal; Modulating the carrier signal with the direct sequence to whiten the spectrum generating a direct sequence spread spectrum signal; transmitting the spread spectrum signal over the channel; Become, The direct sequence is such that the energy in the spectrum is within the passband (7 characterized by having a non-pseudo-random pattern of chips selected to How to do it.

13. A device for transmitting data via a communication channel, A series of digital signals having at least two possible values is transmitted to said communication channel. means for transmitting and receiving by; A method for generating at least two different directional sequences each including a plurality of chips. step by step, the digital signal using the direct sequence to represent different values of the digital signal; means for coding the digital signal; The carrier signal is modulated by the direct sequence and the direct signal with the spectrum is means for generating a sequenced spread spectrum signal; means for transmitting the spread spectrum signal over the channel; The direct sequence is such that the energy of the spectrum resides in the bus band (1). H is a non-pseudorandom pattern of chips selected such that Device.

14. The invention according to claim 12 or 13, wherein each of the direct sequences comprises a plurality of direct sequences. the chip is selected to approximate a frequency changing waveform, and the chip is selected to approximate a frequency changing waveform and A continuous square wave is generated by the chip, and the pulse width of each square wave is equal to the width of the chip. , the frequency of the square wave is in at least a portion of the sequence. A method characterized by gradual changes.

15. A method of transmitting data via a communication channel, the method comprising: A sequence of digital signals having at least two different values is transmitted by said communication line. a step of receiving to transmit; generating first and second spread spectrum signals; representing one value of the digital signal using the first spread spectrum signal; representing the other value of the digital signal by the second spread spectrum signal; coding the digital signal by transmitting a system signal over the communication channel; The first spread spectrum signal has a frequency range in a first direction at least in part. said second spread spectrum signal in the form of a frequency varying spread spectrum signal whose number varies; The tractram signal has at least a portion of the signal in a first direction opposite to the first direction. The form of the first frequency-changing spread spectrum signal whose frequency changes in two directions is A method characterized by having.

16. A device for transmitting data via a communication channel, transmitting a series of digital signals having at least two different values to said communication channel; Therefore, a means for receiving in order to transmit; means for generating first and second spread spectrum signals; and means for generating first and second spread spectrum signals; one value of the digital signal is expressed using the second spread spectrum; said digital signal by representing the other value of said digital signal by a RAM signal. means for coding said spread spectrum signal into said communication channel; a means for transmitting via a channel; The first spread spectrum signal has a first spread spectrum signal over at least a portion of the signal. The signal has the form of a first frequency-varying spread spectrum signal in which the frequency changes in the direction of the signal. , the second spread spectrum signal includes the second spread spectrum signal over at least a portion of the signal. A frequency-varying spread spectrum in which the frequency changes in a second direction opposite to the first direction. Device characterized in that it has the form of a tram signal.

17. The invention according to claim 15 or 16, wherein the first and second spread spectrum The invention is characterized in that the RAM signal is used to modulate a carrier signal.

18. The invention according to claim 15 or 16, wherein the first and second diffusion spectra The RAM signal is characterized in that it is directly transmitted without modulating the carrier signal. invention.

19. The invention according to claim 15 or 16, wherein the frequency change spread spectrum The present invention is characterized in that the system signal is a frequency changing chirp.

20. The invention according to claim 17, wherein the first and second spread spectrum signals is formed by forming a first and second direct sequence 1], and the first and second and a second direct sequence each consisting of a plurality of chips, said chips having frequency varying A continuous square wave is formed by the chip, selected to approximate the waveform , the pulse width of each square wave spans a plurality of said chips, and the frequency of said square wave is equal to the digital signal gradually changes in at least a portion of the sequence; and a second direct sequence to represent different values of the digital signal. and the carrier signal is transmitted by the first and second direct sequences. A direct sequence spread spectrum that is modulated to represent information by the direction of frequency change. An invention characterized in that it generates a RAM signal.

21. The invention according to claim 20, wherein the carrier according to the direct sequence An invention characterized in that the modulation of the signal is a biphase modulation of the carrier signal. .

22. The invention according to claim 20, wherein the spectrum of the spread spectrum signal An invention characterized in that energy is within a certain bass band.

23.1 The invention described in Shimizu paragraph 20, wherein the carrier signal is within the bus band. by a phase reversal sequence chosen such that the energy is more dispersed at The invention is further characterized in that it is further modulated.

24. The invention according to claim 15 or 16, wherein the forward direction and reverse direction change signals are A matching filter for detecting and the matching filter indicating reception of a signal. further includes a receiver with independent tracking to account for differences in timing. An invention characterized by:

25. Coding data using forward and reverse frequency varying spread spectrum signals The information is coded as a difference in the direction of frequency change in the received signal. consists of a series of spread-spectrum signals that have different digital values or and data reception and data represented by different patterns of reverse frequency varying signals. A coding method that receives a series of frequency-varying spread spectrum signals. step and passing the signal through a correlation circuit having forward and reverse outputs; and, Track the forward correlation output to determine if the received signal is a forward frequency varying signal. Sample the output in the forward direction at the timing when it should be received. step and the backward correlation output independently of the tracking of the forward correlation output. is received when the received signal has a reverse frequency change r= An output that samples the backward correlation output at the desired timing and a different timing. reception based on sample values of the forward and reverse correlation outputs obtained by A step for determining whether a signal is a forward frequency change signal or a reverse frequency change signal. Consisting of The forward output of the correlation circuit is the forward frequency varying spread spectrum of the received signal. the backward frequency change step of the received signal; +l] function of a spectral signal.

26, converting the data into a forward frequency varying spread spectrum signal and a reverse frequency varying signal. code using the signal spectrum signal, transmit it, and receive the transmitted signal. This is a device that receives and decodes signals, and the received signal contains information due to differences in the direction of frequency change. Consisting of a sequence of coded spread spectrum signals, different digital values are The frequency is represented by different patterns of forward and reverse frequency varying signals. means for receiving a succession of varying spread spectrum signals; The spread spectrum signal is passed through a correlation circuit having forward and reverse outputs. In order to The backward output represents the correlation of the received signal by the backward frequency change signal. means to represent the forward output of the circuit by means of a spread spectrum signal; The received signal is received when racking and the received signal is a forward frequency changing signal. means for sampling the forward direction output at a timing to be detected; The backward output of the correlation circuit is tracked independently of the forward tracking. and the received signal is received when the received signal is a reverse frequency changing signal. means for sampling the backward direction output at the desired timing; forward or reverse frequency change signals that occur at different timings. and a means for determining based on sample values of the correlation output in the direction and in the reverse direction. A device used as a sign.

27. The invention according to claim 25 or 26, wherein the receiver receives the received signal. a local oscillator for generating a signal to be mixed to demodulate the received signal; The local oscillator is synchronized to the local oscillator used to modulate the signal at the transmitter. the local oscillator has a different frequency than the local oscillator used for modulation. An invention characterized in that it operates based on wave number and phase.

28. A method of transmitting data via a communication channel, the method comprising: A series of digital signals having at least two possible values is transmitted to said communication channel. The station received for transmission via two different direct sequences, each consisting of multiple chips, relative to each other. A step that generates two direct sequences whose differences from each other can be detected regardless of their phase. and using the direct sequence to represent different values of the digital signal. coding the digital signal; Pseudo-randomly varying the entire direct sequence In)If and, Using the direct sequence, a direct sequence spread spectrum with a spectrum of Ste-tube that generates the tractram signal, transmitting the spread spectrum signal over the communication channel; A method characterized by comprising:

29. A device for transmitting data via a communication channel, comprising: A series of digital signals having at least two possible values is transmitted to said communication channel. means for receiving for transmission via; at least two different direct sequences each consisting of a plurality of chips, ! 7- Generates direct sequences whose differences can be detected regardless of their relative phase and means for representing different values of the digital signal using the direct sequence. means for coding the digital signal by; means for pseudo-randomly varying the overall phase of the direct sequence; Using the direct sequence, a direct sequence spread spectrum with a spectrum of means for generating a spread spectrum signal and transmitting the spread spectrum signal to the communication channel; and means for transmitting data via a channel.

30. The invention according to claim 28 or 29, wherein the direct sequence is a carrier. The direct sequence spread spectrum signal is used to modulate the A patent characterized by 31. The invention according to claim 28 or 29, wherein the pseudo-random change of the phase is done so that each successive direct sequence has a pseudo An invention characterized by a randomly changing phase.

32. The invention according to claim 31, wherein two-level coding is used and sub- the bits are represented by one or more direct sequences, the sub-bits being at least arranged in two different sub-bit patterns, the pseudo-random variation of the phase is is done at the sub-bit level, and the phase of the direct sequence is determined for each sub-bit. An invention characterized by pseudo-random changes.

33. The invention according to claim 32, wherein the pseudo-random change is repeated at a time interval greater than the number of sub-bits in the bit, said time interval being The invention is characterized in that the length of the sub-bit pattern is not an integral multiple of the length of the sub-bit pattern.

34. The invention according to claim 28 or 29, wherein the phase is pseudo-randomly The change is the peak power in the spectrum of the signal being transmitted by a pseudo-linear phase change. compared to the peak power in the spectrum when transmitting a signal with no random changes. An invention characterized by reducing

35. Real-level spread spectrum modulation that transmits information as superbits to code data and transmit the coded signal using the per bit is the number of subbits represented by a particular spread spectrum signal. receives a coded signal such that it is coded by a specific sequence of A method for transmitting and decoding the same, receiving the series of spread spectrum signals; and transmitting the received signals to the spread spectrum signal. Correlation circuit designed to identify said specific spectral signal representing a bit. a step that allows the path to pass; The output of the correlation circuit is sampled, and the sub-bit is calculated from the obtained sample value. determining the value of the combination pattern of the A quality indicator can be determined from the size of the sample value of the correlation output used to determine the sub-bit value. of the sub-bits in the decoding of the super-bits; consisting of a stave combining direction and quality indicators for continuity; A method characterized by:

36, a plurality of specific sub-bits represented by a specific spread spectrum signal. Information is transmitted as superbits coded by a sequence A method of coding and transmitting data using two-level spread spectrum modulation a data receiving and decoding device in a computer, the data receiving and decoding device comprising: means for receiving and transmitting the received signal to a particular spread spectrum signal representing said sub-bits; means for passing through a correlation circuit configured to identify the The output of the correlation circuit is sampled, and the sub-bits are calculated from the sample value. means for determining continuous values and the correlation used to determine the values of the sub-bits; means for determining a quality indicator from the magnitude of a sample value of the output of the circuit; the direction and quality input for the succession of sub-bits in the decoding of the super-bits; and means for assembling the indicator.

37. 37. The invention according to claim 35 and 36, wherein each of the superbits is Represented by a constant number of sub-bits, the correlation output for said superbits is direction and quality for a segment of length equal to the length of the predetermined number of subfocuses; The invention is characterized in that each sub-bit is determined based on the quality indicator.

38. The invention according to claim 37, wherein the correlation for the superbit is Matching indicator for each sub-bit in the sub-bit segment determined by distributing the total of data and quality indicators, and A twitching indicator indicates a specific sequence of said sub-bits and said segment. is determined by comparing the values of the actual sub-bits invention.

39. In the invention according to claim 38, the 11j function output for the superbit is before representing the reception pattern of said spread spectrum signal or one superbit; A range of values indicating the probability of one of the specified sequences of sub-bits. and the decoding of the superbits is a correlation with respect to the superbits. Start the super bit tracker when the output exceeds the threshold, and set the threshold of the output between the above) superbit length interval following detection of exceeding the superbit length. The method is characterized in that it is performed by sampling the side eye function output of the cut. Akira.

40, Claim 12.13.15.16.25.26.28.29.35 or 36, wherein the spread spectrum signal is transmitted at an RF frequency. An invention characterized by:

41. The invention according to claim 25 or 26, wherein the forward and reverse change signals The signal is characterized in that it is generated by a direct sequence of forward and backward changes. invention.

42, i! ! A method for transmitting data over a communication line, the method comprising: receives a series of digital signals that can take on two values for transmission over said communication line. and generating a direct sequence of chips. , a reverse direction of the direct sequence to represent different values of the digital signal; code the digital signal using the directional sequence and the direct sequence; the step of transmitting the direct and reverse sequences via the communication signal; A method characterized by:

431 communication A device for transmitting data using a communication channel, A series of digital signals having at least two possible values is transmitted to said communication channel. means for receiving for transmission via; means for generating a direct sequence consisting of a plurality of chips; is said digital by means of a reverse order sequence having a reverse order and said direct sequence. means for coding the digital signal to represent different values of the digital signal; means for transmitting the direct and reverse order sequences via the communication channel; A device characterized by comprising:

44. The invention according to claim 42 or 43, wherein the direct and reverse order sequence The modulated carrier signal is used to modulate the carrier signal. A signal is transmitted back over said communication channel.

45. The invention according to claim 42 or 43, wherein the direct and reverse order sequence The frequency approximation waveform is such that a continuous square wave is formed by the tip. , the pulse width of the square wave spans the plurality of chips, and the frequency of the square wave is equal to the frequency of the square wave. In at least part of the sequence, the forward change sequence has a low frequency from high frequency to high frequency, and from high frequency to low frequency in reverse change sequence. An invention that was once characterized by gradual change.

46. The invention according to claim 42 or 43, wherein the direct sequence and the reverse order Each sequence represents a certain spectrum as fL, and the energy within the spectrum as fL. - is within a certain passband.

47. The invention according to claim 42 or 43, wherein the direct sequence and the preceding The reverse order sequence is transmitted directly without modulation of the carrier. Akira.

48. The invention according to claim 47, wherein the direct sequence and the reverse sequence An invention characterized in that the power is transmitted via a power line.

49. The invention according to claim 44, wherein the modulated carrier signal is in an RF frequency range. An invention characterized by:

50. Coding data using forward and backward versions of the direct sequence Receiving and transmitting data in a method that transmits data by and decoding method, wherein the transmitted signal is in the forward and reverse directions of the direct sequence. a sequence of spread spectrum signals corresponding to the version; receiving the sequence of spread spectrum signals; a forward output representative of the correlation of the received signal to the forward sequence; and a forward output representing the correlation of the received signal to the forward sequence; to generate a reverse direction output representing the opening (of the received signal) relative to the direction sequence. passing the received signal through the correlation circuit made in the forward direction and the backward direction; The received signal is decoded using the counter-correlation output to obtain the coded signal at the transmitter. and restoring digital data.

51, code the data using forward and backward divisions of the direct sequence. and the transmitted signal corresponds to the forward and reverse versions. Reception 1 in a data transmission system having a sequence of spread spectrum signals and a decoding device, means for receiving the sequence of spread spectrum signals; receiving a sequence of system signals and correlating the received signal with the forward sequence; - correlation of the forward output representing the forward output and the received signal to the reverse sequence; a correlation circuit configured to generate a backward output representing The forward and reverse correlation outputs are used to decode the received signal and transmit it to the transmitter. a decoder for restoring digital data coded by A device used as a sign.

52. The invention according to claim 50 or 51, wherein the received signal is connected to the correlation circuit. The invention is characterized in that the invention is demodulated using a carrier signal before being supplied to the carrier.

53. The invention according to claim 50 or 512, wherein the correlation circuit a forward direction ma-noting filter for detecting a direct sequence; and a forward direction direct sequence detection filter; and a reverse matching filter that detects The forward matching filter is a mirror image of the backward matching filter. And, The forward and reverse matching filters share the same shift register. An invention characterized by.

54. The invention according to claim 53, wherein the correlation circuit includes four matching filters. and for each of said forward and reverse sequences, The invention is characterized in that 0 degree and 90 degree plane phase sections are provided.

55. The invention according to claim 54, wherein approximately half the taps of the shift register is assigned to the 0 antiphase section, and the remaining taps are assigned to the 90 degree plane phase section. assigned to the Each of the taps assigned to the O antiphase section and the 90 degree Two additional group taps are configured for each tap assigned to the action. one of these has the same value in the forward and backward sequences. a common group and a phase with opposite values for said forward and backward sequences. Each of these four groups is accumulated to a common cumulative value of 0 degrees. forming a calculated value, a 0 degree difference cumulative value, a 90 degree common cumulative value and a 90 degree difference cumulative value; The output of each of the four filter sections is the corresponding common and accumulated value combination. An invention characterized in that it is formed by merging.

56. The invention according to claim 55, wherein the corresponding common and difference cumulative values described above are The step of combining the common and difference accumulated values in the forward and backward sequences. a step of adding for either one of said sequences and a step of adding for either one of said sequences; an invention characterized in that it has a step of subtracting common and different accumulated values. .

57. The invention according to claim 15 or 16, wherein the forward direction and reverse direction change signals a matching filter for receiving the signal; and a matching filter for receiving the signal. The receiver further includes a receiver that performs independent tracking to capture the difference at the timing shown. An invention characterized by:

Specification (translation) Suitable for RF network communication spread spectrum communication system Background of the invention The present invention provides a spread-spectrum communication system. For use in noisy networks, especially RF channels and ACC electronic lines. Concerning spread spectrum communication systems that can be used.

Spread spectrum transmission uses a much wider band than is required by information theory. This is a method of transmitting information using

In this method, signals are supplied over a wide band and appropriate signal processing is performed. Therefore, the possibility of being affected by noise within a predetermined band is low. Chirp ) In the spread spectrum method, signal bursts called chirps are transmitted. It will be done. Each chirp has an energy dispersion in a predetermined frequency range. This frequency dispersion is , by techniques such as frequency sweep or direct sequence coding. child These chirps may be made asynchronously or as continuous chirps at each synchronous interval. will be sent. Data modulation for the Chirb sequence can be Chirb phase inversion modulation or This can be achieved by methods such as inversion of the chirp frequency sequence. in the receiver The transversal filter is matched to the expected chirp and Each chirp is detected even in a noisy network such as a power line.

In a communication network, multiple transmitters and receivers communicate over a single line. have faith. Therefore, in a certain network, contention nHon) Avoidance and/or collision detection strategies are used so that two or more transmitters This avoids situations where two lines are used at the same time.

U.S. Patent No. 5.09 entitled "Spread Spectrum Communication System for Networks" No. 0.024 and “Timing for Spread Spectrum Communications over Noisy Links” In U.S. patent application Ser. No. 07/863.213 entitled " A device that applies spread spectrum communication to a multi-access network is disclosed. There is. In one of the various disclosed embodiments, a frequency scanned chip is ASK modulation is used to avoid contention, and the data PSK modulation is used for transmission.

Spread spectrum communication is a so-called LAN (local areanet). rk) is used in wireless high-frequency communications. However, such compliance In future technologies, pseudo-random direct sequences (especially maximal linear sequences) techniques are used, in which case synchronization between transmitter and receiver is required and maintained. It will be done. Therefore, in these conventional examples, sufficient phase tracking A circuit is required and therefore the frequency between the transmitted carrier signal and the received carrier signal It cannot tolerate several offsets.

Summary of the invention In a first feature of the invention, a direct sequence approximating the scanning frequency waveform is provided. The chip consists of a chip in which successive square waves form a sequence, and the pulses of the square wave the width spans multiple chips and the frequency of the square wave is Spread spectrum using a direct sequence that varies sequentially over both parts It's communication. In a preferred embodiment, the information is directly related to the frequencies in the sequence. encoded by changing the direction of change, the sequence can be forward or backward The spectrum of the direct sequence is separated from the baseband. the direct sequence modulates the carrier. (i.e., bi-phase modulation of the RF carrier), generates a spread spectrum signal with This bass band characteristic is preferably , preferably has two bus bands centered on the frequency of the modulating carrier.

In other embodiments, the direct sequence is transmitted directly without carrier modulation. It will be done.

The second feature of the present invention is a spread spectrum signal having busband spectrum characteristics. Spread spectrum communication using direct sequences chosen to generate signals. Ru. In a preferred embodiment, an approximate frequency scanning signal is used as the direct sequence. This feature is achieved by using the techniques described above.

The third feature of the present invention is that frequency-changing spread spectrum signals with different changing directions are It is a spread spectrum communication that transmits information over a channel. on this point In a preferred embodiment, two spectral spreads differ only in the direction of frequency change. A scattered signal is used. And the frequency change is in the forward and reverse directions of the frequency change signal. achieved by using the technique described above using change approximation as the direct sequence. will be accomplished. In a variation on this point, the frequency-varying chirps can be transmitted directly. Can also be done.

A fourth feature of the invention is that the transmitted signals are forward and reverse frequency varying signals. and the received signal is fed to a correlation circuit with forward and reverse sequence outputs. and the output of the correlation circuit is tracked independently and forward-directed for decoding purposes. and different sampling timings for sampling the backward correlation output. It is a spread spectrum communication in which timing is used. on this point In embodiments, the forward and reverse changing signals are transmitted in a forward or reverse direction. the receiver modulates the modulated signal at the transmitter. For demodulation that is not synchronized in frequency or phase with the local oscillator used for A local oscillator is used.

A fifth feature of the present invention is that the entire phase of the continuous direct sequence is pseudo-random. , so that the energy is evenly distributed over the frequency band of the transmitted signal. In addition, the direct system reduces the phase cancellation caused by conflicting continuous wave signals. This is spread spectrum communication. In a preferred embodiment in this regard, , each successive direct sequence is pseudorandom with respect to the conventional direct sequence. It has a phase that changes over time.

The sixth feature of the present invention is spread spectrum communication using dual level coding. I believe. In other words, information is transmitted as “superbits”; The superbits of are coded as a special sequence of superbits. , each superbit is represented by a special spread spectrum signal. receiver The output of the correlation circuit is the direction (value) and quality ( This quality indicator is generated as an indicator of It acts as a means of indicating the probability that the indicator is correct. Direction & Quality In The indicators are combined for sub-bit decoding. to this point In a preferred embodiment of the invention, the superbit is a superbit correlation circuit. This superbit correlation circuit decodes the superbit using The direction bits are compared against the unique sub-bit sequence associated with the result of this comparison. are combined into quality bits to obtain the superbit phase corresponding to each successive sub-bit. Generate function output. When the superbit correlation output exceeds the threshold, the superbit correlation output Racking is started and the sample for subsequent superbit decoding is The rings are spaced apart by the length of the superbit.

A seventh feature of the invention is that the direct sequence and the reverse order of the direct sequence are It is a spread spectrum communication that uses the Preferred practices in this regard In an example, the direct sequence is transmitted directly without modulation of the carrier. ( This is the case, for example, in power line transmission. ) or this direct sequence For example, in the RF frequency range, the frequency is used to modulate the carrier signal. It will be done. In this case, the direct sequence approximates the waveform of the changing frequency, and this changing frequency In the waveform, a continuous square wave is formed by the chiller, and the pulses of the square wave are The width of the square wave spans multiple chips, and the frequency of the square wave is a forward frequency change sequence. In case of frequency change, the frequency changes from low frequency to high frequency, and in reverse frequency change, it changes from high frequency to high frequency. over at least part of this sequence. Also, this The direct sequence of is the energy distributed in the bass band away from the baseband. It has a spectrum accompanied by energy.

An eighth feature of the invention is that forward and reverse sequences are used for information transmission. is a method of receiving and decoding spread spectrum signals of the type . In a preferred embodiment in this regard, shift registers and adder circuits are used. and four matched filters: forward 0 and 90° filters and reverse It acts as a 0 and 90" filter in the forward direction. This is useful for identifying direct sequences in the forward and reverse directions.

Because of this discrimination, the matched filter for the forward sequence is is a mirror image of a matched filter. Shift register and adder circuit support To save noise, approximately half the taps in the shift register are set to 00 filter sectors. section and the rest for the 90" filter section. Each of the half taps also has a common value for the values common to the forward and reverse sequences. a common group and a difference group for opposite values for forward and backward sequences. In the end, there are four groups of taps. The touch of these four groups There are four groups: o'' common, 00 different, 90° common, and 90''. four additions A calculation subcircuit is used to perform the summation of each of the four groups of taps described above. It is. The outputs of each of the four filter sections are the outputs of these four subcircuits. easily formed by combining two forces. For example, 0″ forward output is Formed by further adding 0″ differential addition and 06 common addition, 0″ inverse The forward output is formed by subtracting the 06 differential addition from the 0@common addition.

The invention has various advantages. That is, the present invention Provided is an improved communication technology for RF communications in. Furthermore, according to the present invention For example, a carrier sensing multi-channel system can be constructed using inexpensive frequency generation components. An access transceiver is provided. Moreover, the decoding in the present invention is , the phase shift due to the frequency change of the receiver's local oscillator relative to the transmitter's local oscillator. It is insensitive to pitch and frequency shifts. Also used for modulation There is no need to synchronize the local oscillator used for demodulation with respect to the local oscillator.

Additionally, direct sequence pseudo-random phase modulation across the spectral band Improved energy distribution and reduced transmitted peak signal power at a given frequency will decrease. Furthermore, since we use dual-level coding, Matched filter size can be reduced while processing longer direct sequences. It is possible to maintain the operational gain. Also, problems with RF communication in valleys between buildings, etc. Potential multipath noise is reduced by transmitting two redundant sidebands. When the receiver is in a field-free position in one of the sidebands, the Coding is accomplished.

Other features and advantages of the invention follow from the following description of the preferred embodiments and from the claims. It is clear from the description.

Brief description of the drawing FIG. 1 is a block diagram illustrating an RF transceiver according to the present invention.

FIG. 2 is a block diagram illustrating the waveform generation logic of the transceiver of FIG. 1.

Figure 3 shows the superbit synchronization, tracking and data extraction of the transceiver of Figure 1. FIG. 3 is a block diagram of output logic.

4A and 4B illustrate the forward and reverse chip systems used in the transceiver of FIG. FIG.

FIG. 5 is a table showing a complete 360 chip forward sequence.

6A and 6B illustrate the forward and reverse sub-bit systems used in the transceiver. FIG.

FIG. 7 is a schematic diagram showing the structure of a data packet.

FIG. 8 shows the modified superbit used in the preamble of the data packet. FIG.

9A-9D illustrate the effect on timing of frequency shifts at the receiver It is a schematic diagram.

FIG. 10 is a block diagram showing the correlation circuit of FIG. 1.

FIG. 11 is a diagram illustrating the operation of the sub-bit tracking logic.

Figures 12A-12D show the four elements used to configure the matched filter of the correlation circuit. It is a graph showing a subcircuit.

13A-13D show four matched filters configured by the subcircuits. It is a graph.

Description of the preferred embodiment In FIG. 1, an RF transceiver 10 is shown.

The transmitting part of this transceiver is shown at the top of the figure. via RF channel The data to be transmitted is transferred to a computer under the control of application software 16. The signal is supplied to the transmitter via the microprocessor 14. This data (packet) (grouped into blocks) are connected to the microprocessor interface 15. Therefore, it is received and coded by data encoder 12. In addition, this CRC is added when . This data is generated by the waveform generation program 13 at 25 ．． It is converted into a chip sequence with a 2 MHz pulse frequency. Blocks 12 and 1 3 forms ASI'C with the other logic of the receiver. Chip sequence above The signal passes through a 4.2-6.3 MHz band pass filter 18 to obtain band energy. - is removed and amplified by baseband amplifier 20. The output of this amplifier is A 915 MHz carrier fed to the oscillator 20 and generated by the local oscillator 24 The chip sequence is bi-phase modulated. The modulated carrier is an RF amplifier 26 and antenna 28 . The transmitted signal is approximately 910MHz and 9 It consists of two 2.1 MHz wide bands centered at 20 MHz.

The receiving portion of the RF transceiver is shown at the bottom of FIG. RF antenna 28 The received signal passes through an RF/pass filter 30. This nokundo Nox filters can pass either of the two transmitted bands. . The signal passed through the bandpass filter 30 is amplified by the RF amplifier 32, It is demodulated by a mixer 34 and a filter 36. This mixer 3 4 is supplied with the output from a 915 MHz local oscillator 34. Also, bandpass Filter 36 is substantially similar to the transmitter's 4.2-6.3 MHz filter 18.

The demodulated signal passes through a limiter amplifier 40 and is converted into a two-level signal. child The two-level signal is sampled at 4.2 MHz and supplied to the correlation circuit 42. Ru. Correlation circuit 42 has forward sequence and reverse sequence outputs F and R. Ru. These outputs are used by sub-bit synchronization, tracking and data extraction logic 4. 4, and this logic 44 inputs the IN (quality) and direction (val ue) bit for each demodulated sub-bit. Quality and direction bit super Provided to bit synchronization, tracking and data extraction logic 46. This logic The output of block 46 consists of a superbit and one threshold-crossing indicator bit. . Data decoder 48 demodulates the superbit sequence and performs a CRC evaluation check. checks and sends the demodulated data packets to my computer via the interface 15. The data is supplied to the microprocessor 14.

The transceiver described above uses direct sequence spread spectrum modulation and uses this variation. In the key, the code sequence of “1” and “0” corresponds to the pi-phase change of the carrier. Identify the key. However, this sequence is similar to the traditional pseudo-random direct sequence. nor is it a conventional maximum linear sequence. Rather, fig. 4A and 4B, these approximate frequency varying chirps. each sea The can contains 360 chips occurring at a frequency of 25.2 MHz. Also , a single code sequence is used, either as a forward sequence or as a backward sequence. transmitted as a can. For forward sequence, the frequency of the square wave is 4°2M Hz (6 chips per waveform), 6.3MHz (4 chips per waveform) Ru. A reverse sequence is the same pattern transmitted in the opposite direction. This sequence The dither pattern is as shown in the table in Figure 5. It is used to generate gentle frequency fluctuations from 4.2MHz to 6.3MHz. It will be done. The frequency spectra of the forward and reverse sequences are equal to each other and are It covers a band of approximately 4.2 to 5.3 MHz.

In the receiver there are two correlation circuits, one for the forward sequence and one for the backward sequence. is designed to correlate these frequency change sequences. Therefore, Digital sub-bits are transmitted over the channel, in this case one “1” is represented by a sequence in the direction of , and “0” is represented by a sequence in the opposite direction. be done. In some embodiments, these sub-bits can be used to data is transmitted, and each bit in the data packet corresponds to one subbit. However, in order to improve the processing gain, the sub-bits can be maximized in the linear sequence pattern. You can also group them into groups. In this case each maximum linear sequence pattern is seven subbits long. These patterns are complete inverts of each other. three sub-bits (111) of one state, followed by It consists of two sub-bits (00), plus one sub-bit for each state. Sunawa In other words, the 1110010 pattern of subbits shown in Figure 6A is called 1 superbit. The inverse pattern 0001101 shown in FIG. This corresponds to what is called a per bit. Of course, this 1110010 pattern is The sequence of direction and reverse sub-bit sequences is FFFRRFR, where where F is the forward 360 chip sequence and R is the reverse 360 chip sequence. It is Similarly, the 0001101 pattern corresponds to RRRFFRF. Na Oh, the starting point of the pattern is taken out arbitrarily.

The superbits mentioned above are preamplifiers that make up data packets and sequences. Corresponds to the actual bits that make up the pull and packet. Some examples For example, the EIA CEBus protocol information uses pulse width modulation. transmitted. The pulse width modulation in this case is USTS (UNIT SYMBOL T imes). two superbits in the same state and This is followed by one superbit of the opposite state resulting in one logical state (e.g. “0”) UST, one superbit in the same state followed by the opposite state. The superbit represents the other logic state, ie, "1" UST.

Makes the energy of sequences transmitted over a 2.1MHz wide band more uniform For dispersion, pseudo-random phase modulation of maximum length 15 code sequences is Applies to the last subbiton. This repeats the sub-bit sequence This is done by performing an exclusive OR on the 15-bit sequence. This phase modulation is done at the sub-bit level, and 3 in the sub-bit chip sequence. This is done by inverting the position tlJ every 80 chips or leaving it as is. . with a sequence of seven sub-bit lengths (1110010 and 0001101). The relative primeness of the 15-bit sequence This further improves the irregularity of modulation.

This method of using phase modulation involves continuously changing the phase of the transmitted signal. Effective in reducing follow-on interference and improving in-band power dispersion. Tsk The phase modulation of the sequence of signals affects the ability of the matched filter to detect them. will not be given. After all, matched filters are independent of the overall absolute phase of the sequence. This is because forward or backward sequences can be detected accordingly.

Forward/reverse chip sequence, sub-bit grouping, pseudo-random phase The combined effect of modulation is 2. More uniform spread of energy over the 1MH2 band It is. Three elements in these modulations affect the spectrum. modulation Of course, before the Concentrate on the spectral lines. The sub-bits generated at 70KHz are spread over a 2.1MHz wide band. The energy spread is divided into approximately 30 spectral lines. In the sub-bit modulated signal Forward/reverse pattern super with the effect of producing a 10KHz pattern The bits divide the energy within the band into approximately 210 spectral lines. However, , the energy level of each spectral line is not equal to each other.

After all, the approximate frequency change signal in the basic 360 chip sequence Is there a combination of forward and backward sequences in fluctuations and superbits? It is et al. Phase giving a 15 sub-bit phase pattern repeated at 4°7KHz Modulation increases the number of effective spectral lines to over 400 and further increases the power level of the components. to further reduce the peak power density over the 2.1 MHz band.

FIG. 2 shows a specific example of the waveform generation circuit 3. In this circuit, the superbit The data of the output is applied to the input 100 of the circuit. Then, a 3-stage well-formed generator The 7-bit sub-pit sequence generated by the controller 104 and the gate 10 2, the logical sum is performed. The output of gate 102 is 720 bit ROM 101 1i, in which separate copies of the chip sequence are It is stored in the order of direction and reverse direction. 360 bits each for forward and reverse direction is necessary. The 8 bits of the sequence are read from the ROM at a time and the shift register is The signal is supplied to the register 108. This chip sequence is a four-stage integral generator. 15-bit pseudo-random phase modulation sequence generated by A logical sum is performed at gate 110. In addition, 252.2MHz clock and A 178 frequency divider circuit and a counter 116 that cooperate with each other receive the chip from the ROM 10B. control the reading of the sequence.

FIG. 10 shows the configuration of the correlation circuit 42. This correlation circuit has two matching Acts as a filter. One of these two types of matching is forward sequence detection. one for backward sequence detection, and the other for backward sequence detection. These two ma The filter can also be formed independently. In this case, the two filters Each consists of a shift register and an adder circuit, but as mentioned above, there are two matching circuits. Manufactured by sharing shift registers and adder circuits for filters Costs can be lowered.

The local oscillator in the receiver is not synchronized with the local oscillator in the transmitter. , the absolute phase is not preserved in demodulation, and in fact, as two matching filters, 0" and 90" filters are required for each forward and reverse sequence. Ru. If only one filter is provided for each sequence, then For this filter, when it receives a sequence that is exactly 90° phase shifted, This means that there is no sensitivity. Using both 0″ and 90″ filters, two filters are used. By using the maximum value of the output of the It is possible to do so.

In this example, each sequence is 380 bits long, and each sequence is Since it is received at a frequency of 25.2MHz, if four matching filters (forward If the directions 0'' and 90° and the opposite directions O'' and 90'' are configured as usual, then Requires a length of 360 bits and samples the received signal at 25.2MHz. must be able to do so.

Therefore, in order to reduce the size of the matching filter, the received waveform is Undersampling of 4.2 MHz is performed by a sub-sampler. this By doing so, we can create an equivalent waveform that mixes a 4°2-6.3MHz signal into a 4.2MHz waveform. Rear shing occurs and therefore 02. Converted to IMHz spectrum. 0 2. In order to achieve the required sampling accuracy of the IMHz signal, a matching filter is used. The size of is 60 bits, which is a 1/6 reduction. The important thing is the waveform Although the ASIC part except for the component circuit 13 is supplied with a 25°2MHz signal, It is possible to operate at a frequency as low as 4.2 MHz.

To further reduce the complexity of the correlation circuit, the four matching filters are integrated into a single By sharing the resources of the 60-bit shift register 240 and the adder circuit 242, It is formed.

Since symmetry between forward and backward sequences increases the likelihood of sharing, be. Adder circuit 242 is divided into four subcircuits. And each sub-circuit Handles approximately 1/4 of the 60 bits of the shift register, and outputs the subcircuits in different ways are added to generate the desired four matching filter outputs. It takes A shared filter can be configured as follows. Two forward sequences are 9 It is generated as representing a frequency change waveform displaced by II (about 0°). these Because the two waveforms generate two separate matching filters of 90 points each. used for. One combination t-open filter then 90″ filter with 0＠ Assign points with a value greater than the filter, and vice versa for the Oa filter. is configured by assigning it to

These two waveforms have a phase difference of 906 degrees, so the phase difference between the 90° and 08 waveforms is The minimum and maximum points for the related filters are still offset from each other. Yo This leaves us with the more important points for each filter. These points are in this example is represented by a single bit and represents a positive or negative waveform. this In this way, a correlation filter is obtained that retains both the forward O'' and 90'' points. , which can be used for two approximately equal correlation adder circuits.

(reverse sequence) Since the 0-related filter is a mirror image of the forward direction, the backward sequence The filter is obtained by inverting the bits at each 0″ and 90° point in turn. It will be done. The inverted mirror image and forward filter points are approximately Half are the same Nu (same value), and about half are different (opposite values), so the two directions To represent a gender filter, we can split an existing filter into two parts. can.

That is, there are common subparts and different subparts.

Then, common subparts and and different subparts are added. To form the adder circuit for the reverse filter , the distinct subparts are subtracted from the common subpart. The above steps are Used for both the 0'' and 90° portions of the filter.

As a result, the four sub-circuits Comb, Com90s DifO and Dif90 obtained, and these are appropriately added to form o″ and o″ for forward and backward sequences. and 90@correlation value. That is, ForO-ComO+Di fO RevO=ComO-Di fO For90-Com90+Di f90Rev90=Com90-Di f90 It is.

In FIGS. 12A-12D, the service is constructed using a 59-tap shift register. The block circuit is shown. These 59 taps (0 to 58) are in the horizontal direction of each diagram. shown along. And what does each tap have a value of +1.0 or -1? . Here, +1 and -1 indicate valid filter taps for the subcircuit, and 0 indicates the absence of a tap. Each subcircuit uses approximately 1/4 of the total taps .

13A-13D, addition or subtraction of subcircuits is performed according to the description above. A matching filter formed by is shown. Direction for same phase Directional and reverse filters are exactly the same except that they are arranged in opposite directions; The 00 and 90″ filters for the forward sequence use different parts of the 59 taps. There is.

In Figure 3, the configuration of sub-bit synchronization, tracking and data extraction logic is shown. It is shown. Matching filter detects forward and backward sequences Separate forward and reverse sequence tracking for different timing Logic is required. Before explaining this tracking logic, let's understand why it works. Briefly explain why it is necessary. A small amount of frequency is generated in the transmitter and receiver local oscillators. When wavenumber fluctuations occur, the frequency content of the received chip sequence shifts slightly higher in the frequency band. Shift to the frequency side or lower frequency side.

These shifts are then matched by a matching filter to the forward and backward sequences. This results in a shift in detection timing. These timing shifts are not a problem. However, the direction of timing shift for forward and reverse sequences is different. There is a fact.

Figures 9A-9D illustrate the effects of oscillator frequency shifts on the receive sequence.

The chip sequence shown in Figure 9A is the original forward displacement sequence, where the chip The deviation from 4.2 MH2 to 6.3 MHz is approximated. No peak correlation output occurs. ) The alignment of the inter-eye circuit is indicated by point C in the figure.

The chip sequence shown in Figure 9B has been frequency shifted by 200KHz. The chip starts at 4.0MHz and ends at 6.1MHz. Shadow of frequency shift The effect can be improved by slightly changing the position of alignment C of the correlation circuit that produces the maximum output. Ru. The maximum correlation output is such that the right edge of the correlation output has a frequency content of approximately 4.2 MHz. Occurs when a match is made to a part of a sequence. Original sequence without frequency shift (Figure 9A), the maximum correlation output occurs when the correlation circuit is at the earliest edge of the sequence. It occurs when fl is combined. However, in a frequency-shifted sequence In this case, the maximum correlation output occurs slightly within the scan pattern. This alignment If the correlation output reaches its maximum timing is shifted to a slightly earlier time, That's what I mean. This timing difference is suggested by arrows 208 and 210. It is. For frequency-shifted sequences, the timing at which the correlation output is maximum (indicated by arrow 210) for sequences without frequency shifts. This is slightly earlier than the lever timing (arrow 208).

9C and 9D show the reverse sequence without frequency shift and with frequency shift. A similar comparison is shown between the reverse sequences. In this case, the maximum correlation output is A similar phenomenon occurs, except that the timing occurs later rather than earlier. child These are indicated for timing by arrows 212 and 2I4.

If the direct sequence used is not frequency-biased but instead uses a conventional pseudorandom (maximum linear sequence), the effect of frequency shift is t Rather than a simple timing shift of the correlated output, there is a significant or This will lead to fatal quality deterioration. The reason is that traditional pseudo-random sequences It has 11 frequency components over the duration of the period, and the frequency shifts are correlated. It is not a simple shift in alignment between the circuit and the receive sequence that impairs the received signal. This is because it greatly destroys all correlations.

The sub-bit synchronization, tracking and data extraction logic 44 operates as follows. Ru. Each of the correlation outputs F%R is provided to the threshold sensing logic It. Change in correlation output The range of motion is from 0 to 15. Therefore, the threshold value of 10 is the first carrier detection, i.e. Used for initial detection of direction or reverse sequences. If the threshold is reached, The threshold logic detects a local peak in the correlation output when Go through the steps to make sure. This logic uses one 4.2MHz chronoquin When the F correlation output before one clock is large, Adjust the clock and look at the light again. This procedure reduces the value of the preceding correlation output. It can be continued until When the value of the correlation output one clock ago is below the threshold, forward and reverse tracking and timing logic.

Figure 11 shows the tracking following detection of the first above-threshold output in the forward correlation output. It shows the operation of the processing logic.

Both F and R trackers are indicated by wind brackets 300, 302 At the timing (more precisely, the timing of the peak output exceeding the threshold) I am forced to start. At this timing, the forward tracker F is 60 4.2MHz clocks from the peak that started the tracker. Wait until the contents of the 3-bit wide window 304 centered on the block are inspected. Ru. 60 4.2MHz clocks corresponds to 60 bits of the correlation circuit, which takes approximately 14 miles. It is a cross second. However, the backward tracker R is backward). What is the correlation output? Effect of frequency shifts introduced by modulation on the non-synchronized and forward correlated outputs It skews by that amount. Therefore, if the tracker starts in the first 30 clock timing positions, i.e. in the reverse direction at position 306. The tracker monitors the backward correlation output for values that exceed a threshold. If the wind bracket As shown by cut 308, the value exceeding the threshold is within 90 clock timings. A rule for selecting the maximum correlation output if it is found before the forward correlation circuit described above. The same rules as given in ) are used and the backward tracker is reset. A 60 clock counter is started from the time of the maximum correlation output. conversely, backwards ) If a value exceeding the threshold of the D function output is not found before the expiration of 60 clock periods. output is sampled in the forward direction (at 60 clock intervals). (maximum value within the 3-clock interval window), reverse direction The racker exceeds the threshold for the next 30 clock timings, i.e. until position 310. Continue to monitor output. If an output exceeding the threshold is found, its location The reverse tracker is reset and restarted. From this point on, two tigers The clocks operate independently, each with a 3-clock width width every 60 clock intervals. This is done by looking at the parameters and choosing the highest value among them. If the backward correlation exceeds the threshold If a force starts both trackers, the reverse procedure to that described above occurs.

Each tracker is a 3-clock centered 60 clocks from the last sampling. Select the maximum output within the block width window and feed that output to the data extraction logic . The data extraction logic compares the forward and reverse outputs and determines which output is greater. The sub-bit determines whether it is a forward sequence or a backward sequence. both If the outputs of There are certain rules. The data extraction logic sets the “direction°” bit as “1” or “ 0" output. In this case, "1" indicates a forward sequence and "0" indicates a backward sequence. Indicates the sequence.

The trackers adjust their tracking every 60 clock intervals. each The tracker determines whether the maximum correlation output is on the left or the center in a 3-clock width window. Determine whether it is the right side or the right side. This determination is based on the clock time of the tracker on the winning side. used to adjust the timing by +1.0 or -1 clock. Here, I won The tracker on the other side is the tracker that corresponds to the side determined by the data extraction logic. It is a mosquito. That is, if the data extraction logic If it is determined that the This is not done for backward trackers. Such a slight The lock timing adjustment is due to variations between the transmitter and receiver clock circuits. This is to accommodate timing changes that occur.

The data extraction circuit also outputs a "quality" bit. This quality bit exceeds the threshold It is 1 if the judgment is made based on the output that is received, and it is 1 if the judgment is made based on the output that is below the threshold. It is 0 when a separation is made. Therefore, for each decoded sub-bit, direction bit (indicates whether the sub-bits are decoded as a forward or reverse sequence) ) and the quality bit (indicates whether the determination was made by the correlation output exceeding the threshold) ) is generated.

FIG. 3 shows the configuration of superbit synchronization, tracking and data extraction logic 46. It shows. Two bit shift registers 270, 272 store the latest seven sub-registers. The bit direction and quality bits are held respectively. For each sub-bit interval, Each sub-bit in direction bit shift register 270 is sent to logic circuit 276. The correct sub-bit pattern for the “1” superbit (i.e. 11 10010). This correct subbi soto pattern is generated by a number generator 274 that generates matching bits.

If the direction bit matches the correct pattern, the matching bit It is set to 1, and set to O when no matching is performed. series of matching When all of the focus points are equal to 1 (i.e. 111’1llll), “1” super A series of matches means that all sub-bits correspond to the bit pattern. When all of the pinpoints are O (i.e. ooooo).

O), all subbi nodes corresponded to the “0” superbit pattern. means. Adder 278 adds each match according to the rules shown in the table of FIG. Add ngbint to each quality bit. If Masochingubi Soto is O, 1 indicates that a sub-soto judgment was made based on the quality bit value above the threshold value. If so, the adder outputs 0. This means that the sub-bit to be J’M is 0 super bit. This indicates that there is a high possibility that it was properly decoded as part of the test.

However, if the matching focus is 0 and the quality bit is If it is 0, indicating that the threshold was not exceeded in the coding, the adder Outputs 1. This means that the subbits are correctly decoded as part of the 0 superbit. This indicates that there is a low possibility that the At the same time, the adder 278 outputs “ Outputs 3 for “1” matching bit and “1” quality bit, and outputs “1” matching bit. Output 2 is output for the checking bit and the "0" quality bit. shift register All seven adder outputs for each sub-bit of the adder are accumulated and output from the adder. This accumulated value becomes the superbit correlation output (correlator). , this correlation output can vary over a range of 0 to 21. The value of this correlator is compared comparator 280 and comparator 280 converts the super - determine whether the bit is “1” or “0”. Simply put, too If the adder output S is 11 or more, the super bit is set to 1m and the addition If the output S is less than 10, the superbit is set to 0''.

In addition, 280 uses the superbit thresholds 5 and 16, and Determine whether the value is greater than or less than the value. If the output of the adder is 16 or more, If super bit 1 is greater than or equal to the threshold and the output of the adder is less than or equal to 5, then super Bit 0 is greater than or equal to the threshold. Discrimination above this threshold ゛ is about superbit is important for the synchronization of It is also important for determining what is in the If the comparator outputs above the threshold If generated in a given sub-bit, synchronization logic 282 registers register 2. Assuming that the 7 subbits accumulated in 70.272 correspond to the superbit and start the 7-supply clock. From that point on, the data packet In the forward direction, superbit decoding is performed for each of the seven outputs of the comparator. be done. This decoding is based on whether the output of adder S is greater than or equal to the reference value. It is done. In other words, if S is 11 or more, 1 is given to the superbit. If S is less than or equal to 10, 0 is given for S. packet start During symbol (initial packet configuration sequence) acquisition, each time other than the 7th output The superbit output above the threshold that occurs at the superbit level re-identification It gives rise to a period. Regarding this point, please refer to the explanation below.

The structure of the data packet shown in FIG. U.S. Patent Application Box 077873 entitled "Timing of Spread Spectrum Communications" , 213. Each transmitted packet is The contention avoidance preamble 120 is added to the packet start signal. Bol 122 continues. This packet start symbol 122 is the initial E. It is a superbit of a given sequence called OF. This package The packet body data 124 follows the start symbol. Illustrated chopsticks However, each packet ends with an end-of-packet symbol (EOP). stop This is followed by a cyclic redundancy code (CRC) for error detection.

The transceiver initiates a transmission over the RF medium. And in this medium Contention avoidance is achieved using avoidance preamble 120. Sending When the transmitter attempts to access the communication channel, the transmitter It is necessary to detect a fixed length of idle time. This predetermined time is for messages. is a function of the priority of That is, higher priority messages will receive lower priority messages. Requires less free time compared to Tsage. The length of idle time that will be given to each transmitter is of pseudorandom length at an interval determined by the priority of the message. Randomize by adding additional time intervals. CEBus In, 100 microseconds UST (UnltSymbol It is measured by the cumulative number of (Tinge). And the range of this empty time length is approximately It ranges from 40 to 20 UST.

This idle time is determined by a threshold at the superbit or subbit level at the receiver. Defined as a matching filter that does not recognize outputs exceeding .

After the transmitter detects the required free time, the transmitter transmits the preambles 120 and 11. ASK with a pitch of 4 microseconds (amplitude sl+ift k eying) begins transmitting the modulated superbits 130 of the sequence. This modulation The superbit is shown in FIG. Seven sub-bits 132 are arranged, each Each bit is approximately 14.3 microseconds long, and the length of each 7 bits is 2.0 microseconds. A black second empty time 134 is inserted. As a result, the modulation superbit The length of is 114 microseconds.

Above: The preambles are from 8 to 16 114 microsecond periods. , and if there is a modulated superbit (upper state) or (not (lower state). The length of the preamble is variable. For example, this preamble includes eight pulse width modulated symbols.

and a logic 1 is a single 114 microsecond interval followed by a It is represented by a tate change. That is, the upper state and the lower state that follows Tate or vice versa. On the other hand, -riO changes from no state change to state change. It is represented by two subsequent 114 microsecond intervals. i.e. , two higher states followed by one lower state, or vice versa. Shown in Figure 7 In the example above, the eight symbols are 0111 (1111) and the preamble The length of is 10 114 microsecond periods. Among these, two 0 syns Bol uses two 114 microsecond periods, six 1 symbols are one 1 A 14 microsecond period is used. Usually the CEBus preamble There are 8 symbols, so 256 different preambles are possible. Ru.

There are many different actual patterns used in transceivers, and they can be triggered in a pseudorandom manner. Assigned to each transceiver or its master station. In the lower state mentioned above, If the transceiver is not transmitting a chirp, the transceiver will not be transmitting. Monitors media usage. In other words, the sub-bit correlation output above the threshold is monitored. I look at it. If in use, the transmitter uses the next modulated superbit Leave immediately without sending out. If not in use, next modulation super bit is sent. By the time the preamble sequence is completed, the transmission The device continues transmitting and other competing transmissions (+; the device leaves the contention.

If the transmitter survives the tension avoidance procedure, the transmitter fJ A packet start symbol 122 is immediately transmitted. This packet starts Bol 122 is a series of superbits of the same phase (i.e. 1) followed by the opposite It consists of one superbit of one unit (i.e. 0).

These are the super bits already mentioned. Each of these superbits is 1 It has a length of 00 microseconds and consists of 7 subbits. sub-bit each is 10,077 microseconds or approximately 14.3 microseconds long It is. These superbits are transmitted without intervening empty spaces, so The pitch is 100 microseconds. Immediately after the packet start symbol is Packet data 124 follows. This packet data is the packet start symbol. It is transmitted using the same superbits as in the file.

As detailed in the above-mentioned U.S. patent application, the receiver uses contention avoidance. Do not participate in the procedure. Then, the receiver receives the packet start symbol of the communication medium. Simply monitor and detect a chip sequence that does not match the packet start symbol Sometimes it resynchronizes. Is the receiver undergoing a contention avoidance procedure? is not detected and the receiver starts from the preamble or packet start symbol. respond to the detected sequence.

At the sub-bit level, the receiver receives 14.3 microseconds as described above. A new sub-bit of the reverse or forward sequence within every three clock windows. Expect to receive emails. Prior to capturing the packet start symbol The synchronization, tracking and data extraction logic continues to detect outputs that exceed the threshold. Check the correlation output FR. If such output is within the expected correlation peak A 7-clock wide window located at the center or 60 4.2 MHz clocks apart. outside the sub-bit and super-bit tracks if detected. will be resynchronized. Therefore, the receiver or When a modulated superbit containing a bit is detected, a resynchronization operation is performed repeatedly. Na 16.3 microsecond pitch means 2 microseconds between sub-bits. This is because there is a blank period between the two groups. Therefore, all of the receivers that monitor the channel performs a constant resynchronization operation in the contention avoidance phase, but The resynchronization operation where the signal transmits the packet start symbol is stopped. death However, if for some reason the packet start symbol is The correlation outputs above the threshold were separated by a pitch of 14.3 microseconds before the insertion. If it occurs outside of a 7-clock wide blackout window, the synchronization logic performs a resynchronization operation.

Also, the superbit output above the threshold is expected before the packet start symbol is captured. If detected by comparator 280 outside of each of the 7 sub-bit intervals A resynchronization operation is performed at the superbit level. this super bit i 1g synchronization occurs only at the level of the superbit, so in this case, Superbit data is cleared and superbit alignment is resynchronized It is moved by. and the one generated by sub-bit logic 48 Both direction and quality bits are undisturbed.

The rules used to qualify packet start symbols are as follows. Sunawa (1) resynchronization at either the subbit level or the superbit level; Four consecutive superbits are detected without any delay occurring. (2 ) The last four superbits have the pattern 1110 or 0001.

(3) Correlation where at least one supra-threshold superbit caused the last resynchronization operation. be detected within the expected 100 microsecond pitch. It is.

Therefore, the packet start symbol consists of eight 100 microsecond supervises. However, the receiver needs a superpower to conclude that it has received this symbol. It is not necessary to detect the complete pattern of bits. What happens is that the resynchronization operation In subsequent periods, at positions separated by an expected 100 microseconds, Confirm the correlation and match the detection pattern to the end of the packet start symbol It is with ng. In other words, the pattern of the last part of the packet start symbol is 1110 or OOO1, 3 superbits of one polarity followed by the other polarity It is one superbit of sex. Therefore, there are two threshold supercorrelations in total. One is initiated by resynchronization and the other is correlation confirmation. pa These rules for recognizing packet start symbols apply to the transmission of such parts. It is designed to increase the processing gain of the packet body, and has a large They match exactly.

After the packet start symbol is captured, the resynchronization operation is stopped and the data is captured regardless of whether the threshold exceedance occurs at an incorrect timing.

The data is determined as soon as the output of the Z-bit comparator 280 exceeds the base. This is done collectively, so if the output is 11 or more, the superbit will contain 1. If the output is less than or equal to 10, the superbit is assigned 0. It will be done. If an error occurs, this error is caused by checking the CRC of the data packet. Therefore, the application software usually instructs 11) to send the packet. I will do it.

Sub-bit tracking and data extraction logic 44 performs packet body extraction. Continuously confirm that the carrier exists during the download period. i.e. subbi This is confirmation that calls are still being received. This verification can be done in a variety of ways. However, in a preferred embodiment of the invention, the above-threshold sub-bits are 32 It uses a simple rule that each subbit must be captured. Yo So, if the logic 44 outputs the above-threshold output from the correlation output over 32 sub-bits, If the receiver does not receive a carrier, it assumes that it has lost the carrier and the application Notify the application software and return to packet start symbol monitoring mode. It is.

Other variations are within the scope of the following claims. For example, in some variants, the order Direction and reverse change chirbes are used in place of the direct sequence technique of the present invention You can also do that. This applies, for example, to "Through a Noisy Medium" filed on April 30, 1992. U.S. Patent Application No. 07/863 entitled ``Timing of Spread Spectrum Communications'' , No. 213. Spread spectrum communication technology is more than just an RF channel. Other media are also for H, for example, 1. ．． i technology is power line It is also used for communication, and direct sequences are transmitted directly without carrier modulation. It is.

°1° sub bit Figure 4A Figure 4B Figure 5 1 “Super Bit Figure 6A “O゛Super Bits 6B Continuation of front page (81) Designated countries EP (AT, BE, CH, DE.

DK, ES, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE) , 0A (BF, BJ, CF, CG, CI, CM, GA, GN, ML, MR, NE, SN.

TD, TG), AT, AU, BB, BG, BR, BY.

CA, CH, CZ, DE, DK, ES, FI, GB, HU, JP, KP, KR, KZ, LK, LU, MG, MN, MW, NL, No, NZ, PL, PT, RO, RU.

SD, SE, SK, UA, VN

Claims (57)

[Claims] 1. A method of transmitting data over a communication channel, the method comprising: A series of digital signals having at least two possible values is transmitted through said transmission channel. a step of receiving to send to; A step that generates at least two different directional sequences each including a plurality of chips. Tep and converting the digital signal to different values of the digital signal using the directional sequence; coding the digital signal to represent Using the direct sequence to generate a direct sequence spread spectrum signal a step of transmitting a spread spectrum signal over said channel; Consisting of The chips are selected to approximate the frequency variation and are continuously A square wave is formed, and the pulse width of the square wave spans the plurality of chips. characterized in that the frequency of the square wave varies over at least a portion of said sequence method. 2. A device for transmitting data over a communication channel, the device comprising: A series of digital signals having at least two possible values is transmitted to said communication channel. at least two different means each comprising a plurality of chips; means for generating a direction sequence; representing the value of the digital signal using the directional sequence; a means of coding by How to generate a direct sequence spread spectrum signal using the direct sequence step by step, means for transmitting the spread spectrum signal via the channel; , The chip is selected to approximate a frequency varying waveform and the chip is successively rectangular. The pulse width of each square wave is formed by a plurality of chips, and the pulse width of each square wave is form his frequency changes gradually over at least part of the sequence. Featured device. 3. 3. The invention according to claim 1 or 2, wherein the direct sequence is a carrier signal. used to modulate the direct sequence spread spectrum signal and generate the direct sequence spread spectrum signal. An invention characterized in that it is used for 4. The invention according to claim 1 or 2, wherein the direct sequence is a carrier signal. An invention characterized by direct transmission without modulation. 5. The invention according to claim 1 or 2, wherein the direct sequence is an approximation of the waveform. An invention characterized by being different in the direction of change. 6. 6. The invention according to claim 5, wherein the digital signal has two levels of bits. continuous, there are two different directional sequences, one sequence is forward the other sequence involves a change in the opposite direction, said forward change being represents one level of the recorded pit, and said opposite change represents the other level of said pit. An invention characterized by: 7. The invention according to claim 1 or 2, wherein the direct sequence comprises a spectrum. and the energy of the spectrum is within a certain passband. invention. 8. The invention according to claim 3, wherein the modulated carrier signal has a certain spectrum. and the energy within said spectrum is within one or more passbands. An invention that is a sign. 9. 9. The invention according to claim 8, wherein the modulated carrier transmitted within the channel The rear signal consists of two parts that are approximately equidistant above and below with respect to the carrier signal. a passband with sufficient information to decode the signal; An invention characterized in that it includes a station. 10. 4. The invention according to claim 3, wherein the carrier signal is connected to the direct sequence. Therefore, a sold-out characterized by bi-phase modulation. 11. 4. The invention according to claim 3, wherein the modulated carrier signal is in an RF frequency band. An invention characterized by something. 12. A method of transmitting data over a communication channel, the method comprising at least two A series of digital signals having possible values are transmitted by said communication channel. the step of receiving the Generate at least two different directional sequences each consisting of multiple chips step and the digital signal for representing different values of the digital signal using the directional sequence; a step of coding the digital signal; A carrier signal is modulated by the direct sequence to generate a direct signal having a spectrum. generating a tangent sequence spread spectrum signal; transmitting the spread spectrum signal over the channel; Become, The direct sequence indicates that the energy in the spectrum is within the passband. characterized by having a non-pseudo-random pattern of chips selected to Method. 13. A device for transmitting data over a communication channel, the device comprising: A series of digital signals having at least two possible values is transmitted to said communication channel. means for transmitting and receiving by; A method for generating at least two different directional sequences each including a plurality of chips. step by step, the digital signal using the direct sequence to represent different values of the digital signal; means for coding the digital signal; The carrier signal is modulated by the direct sequence and the direct signal with the spectrum is means for generating a sequenced spread spectrum signal; means for transmitting the spread spectrum signal over the channel; The direct sequence is such that the energy of the spectrum resides in the passband. A device characterized in that it has a non-pseudo-random pattern of chips selected to . 14. 14. The invention according to claim 12 or 13, wherein each of the direct sequences comprises a plurality of direct sequences. the chip is selected to approximate a frequency changing waveform, and the chip is selected to approximate a frequency changing waveform and A continuous square wave is generated by the chip, and the pulse width of each square wave is equal to the width of the chip. , the frequency of the square wave is in at least a portion of the sequence. A method characterized by gradual changes. 15. A method of transmitting data over a communication channel, the method comprising: A sequence of digital signals having at least two different values is transmitted by said communication line. a step of receiving to transmit; generating first and second spread spectrum signals; representing one value of the digital signal using the first spread spectrum signal; representing the other value of the digital signal by the second spread spectrum signal; coding the digital signal by transmitting a system signal over the communication channel; The first spread spectrum signal has a frequency range in a first direction at least in part. said second spread spectrum signal in the form of a frequency varying spread spectrum signal whose number varies; The tractram signal has at least a portion of the signal in a first direction opposite to the first direction. The form of the first frequency-changing spread spectrum signal whose frequency changes in two directions is A method characterized by having. 16. A device for transmitting data over a communication channel, the device comprising: transmitting a series of digital signals having at least two different values to said communication channel; Therefore, a means for receiving in order to transmit; means for generating first and second spread spectrum signals; and means for generating first and second spread spectrum signals; a second spread spectrum signal to represent one value of the digital signal; said digital signal by representing the other value of said digital signal by a system signal. means for coding a signal and transmitting the spread spectrum signal to the communication channel; a means for transmitting via a The first spread spectrum signal has a first spread spectrum signal over at least a portion of the signal. The signal has the form of a first frequency-varying spread spectrum signal in which the frequency changes in the direction of the signal. , the second spread spectrum signal includes the second spread spectrum signal over at least a portion of the signal. A frequency-varying spread spectrum in which the frequency changes in a second direction opposite to the first direction. Device characterized in that it has the form of a tram signal. 17. The invention according to claim 15 or 16, wherein the first and second diffusion spectra The invention is characterized in that the RAM signal is used to modulate a carrier signal. 18. The invention according to claim 15 or 16, wherein the first and second diffusion spectra The RAM signal is characterized in that it is directly transmitted without modulating the carrier signal. invention. 19. The invention according to claim 15 or 16, wherein the frequency change spread spectrum The present invention is characterized in that the signal is a frequency changing chirp. 20. 18. The invention according to claim 17, wherein the first and second spread spectrum signals is formed by forming a first and second direct sequence, said first and second Each of the two direct sequences consists of a plurality of chips, each of which has a frequency-varying wave. Successive square waves, chosen to approximate the shape, are formed by the chip, each The pulse width of the square wave spans the plurality of chips, and the frequency of the square wave spans the number of chips. the digital signal gradually changes in at least a portion of the first and second code to represent different values of said digital signal using a second direct sequence; the carrier signal is modulated by the first and second direct sequences. A direct sequence spread spectrum that represents information by the direction of frequency change An invention characterized by generating a signal. 21. 21. The invention according to claim 20, wherein the carrier according to the direct sequence An invention characterized in that the signal modulation is biphase modulation of the carrier signal. . 22. 21. The invention according to claim 20, wherein the spectrum of the spread spectrum signal is An invention characterized in that energy is within a certain passband. 23. 21. The invention according to claim 20, wherein the carrier signal is within the passband. by a phase reversal sequence chosen such that the energy is more dispersed at An invention characterized in that it is further modulated. 24. The invention according to claim 15 or 16, wherein the forward direction and reverse direction change signals are a matching filter for detecting and said matching filter indicating reception of a signal; further includes a receiver with independent tracking to account for differences in timing. An invention characterized by: 25. Coding data using forward and reverse frequency varying spread spectrum signals The information is coded as a difference in the direction of frequency change in the received signal. consists of a series of spread spectrum signals with different digital values in the forward direction. and data reception and data represented by different patterns of reverse frequency varying signals. A coding method that receives a series of frequency-varying spread spectrum signals. step and passing the signal through a correlation circuit having forward and reverse outputs; and, Track the forward correlation output to determine if the received signal is a forward frequency varying signal. The forward correlation output is sampled at the timing when it should be received at the same time. step and the backward correlation output independently of the tracking of the forward correlation output. Should be tracked and received if the received signal is a reverse frequency changing signal An output that samples the backward correlation output at a timing, and an output that samples the backward correlation output at a different timing. The received signal is calculated based on sample values of the forward and reverse correlation outputs obtained during a step of determining whether is a forward frequency change signal or a reverse frequency change signal; It consists of, The forward output of the correlation circuit is the forward frequency varying spread spectrum of the received signal. the backward frequency change step of the received signal; A method characterized in that it represents the correlation of spectral signals. 26. The data is converted into a forward frequency varying spread spectrum signal and a reverse frequency varying spread spectrum signal. Coding using a spread spectrum signal, transmitting it, and receiving the transmitted signal. The received signal has information that is transmitted and decoded due to differences in the direction of frequency change. Consisting of a sequence of coded spread spectrum signals, different digital values are The frequency is represented by different patterns of forward and reverse frequency varying signals. means for receiving a succession of varying spread spectrum signals; The spread spectrum signal is passed through a correlation circuit having forward and reverse outputs. In order to The backward output represents the correlation of the received signal by the backward frequency change signal. means representing the signal by a spread spectrum signal and tracking the forward output of the correlation circuit. The received signal is received when the received signal is a forward frequency changing signal. means for sampling the forward output at the desired timing; The backward output of the correlation circuit is tracked independently of the forward tracking. and the received signal is received when the received signal is a reverse frequency changing signal. means for sampling the backward direction output at the desired timing; forward or reverse frequency change signals that occur at different timings. and a means for determining based on sample values of the correlation output in the direction and in the reverse direction. A device used as a sign. 27. 27. The invention according to claim 25 or 26, wherein the receiver receives the received signal. a local oscillator for generating a signal to be mixed to demodulate the received signal; The local oscillator is synchronized to the local oscillator used to modulate the signal at the transmitter. the local oscillator has a different frequency than the local oscillator used for modulation. An invention characterized in that it operates based on wave number and phase. 28. A method of transmitting data over a communication channel, the method comprising: A series of digital signals having at least two possible values is transmitted to said communication channel. receiving for transmission via; two different direct sequences, each consisting of multiple chips, relative to each other. A step that generates two direct sequences whose differences from each other can be detected regardless of their phase. and using the direct sequence to represent different values of the digital signal. coding the digital signal; pseudo-randomly varying the overall phase of the direct sequence; A direct sequence spreading spectrum having a certain spectrum using the direct sequence. generating a tractram signal; transmitting the spread spectrum signal over the communication channel; A method characterized by comprising: 29. A device for transmitting data over a communication channel, the device comprising: A series of digital signals having at least two possible values is transmitted to said communication channel. means for receiving for transmission via; at least two different direct sequences each consisting of a plurality of chips, Generates direct sequences whose differences from each other can be detected regardless of the relative phase of the ridges. and representing different values of the digital signal using the direct sequence. means for coding said digital signal; means for pseudo-randomly varying the overall phase of the direct sequence; A direct sequence spreading spectrum having a certain spectrum using the direct sequence. means for generating a spread spectrum signal and transmitting the spread spectrum signal to the communication channel; and means for transmitting data via a channel. 30. 30. The invention according to claim 28 or 29, wherein the direct sequence is a carrier. The direct sequence spread spectrum signal is used to modulate the An invention characterized by: 31. The invention according to claim 28 or 29, wherein the phase pseudo-randomly changes. is done so that each successive direct sequence has a pseudo An invention characterized by having a phase that changes randomly. 32. 32. The invention according to claim 31, wherein two-level coding is used, the bits are represented by one or more direct sequences, said subbits being at least arranged in two different suppitvacunes, the pseudo-random variation of the phase is is done at the subbit level, and the phase of the direct sequence is changed for each subbit. An invention characterized by pseudo-random changes. 33. 33. The invention according to claim 32, wherein the pseudo-random change repeated at a time interval greater than the number of subpits in the target, said time interval being The invention is characterized in that the length of the sub-bit pattern is not an integral multiple of the length of the sub-bit pattern. 34. The invention according to claim 28 or 29, wherein the phase is pseudo-randomly varied. The peak power in the spectrum of the signal to be transmitted is expressed as a phase pseudo-run. Compared to the peak power in the spectrum when transmitting a signal with no dam change, An invention characterized by reducing the amount of 35. Real-level spread spectrum modulation that transmits information as superbits to code data and transmit the coded signal using the -Per-pit is a plurality of sub-bits represented by a particular spread spectrum signal. receives a coded signal such that it is coded by a specific sequence of A method for transmitting and decoding the same, receiving the series of spread spectrum signals; and transmitting the received signals to the spread spectrum signal. Correlation circuit designed to identify said specific spectral signal representing pupit. a step that allows the path to pass; The output of the correlation circuit is sampled, and the sub-picture value is calculated from the obtained sample value. determining the value of the combination pattern of the A quality indicator can be determined from the size of the sample value of the correlation output used to determine the sub-bit value. and determining the sub-bits in the decoding of the super-bits. combining direction and quality indicators for the sequence; A method characterized by: 36. Multiple specific subbits represented by a specific spread spectrum signal Information is transmitted as superbits coded by a sequence A method of coding and transmitting data using two-level spread spectrum modulation a data receiving and decoding device in a computer, the data receiving and decoding device comprising: means for receiving and transmitting the received signal to a particular spread spectrum signal representing said subbits; means for passing through a correlation circuit configured to identify the The output of the correlation circuit is sampled, and the sub-bits are calculated from the sample value. Means for determining continuous values and the correlation used to determine the value of the sub-bits means for determining a quality indicator from the magnitude of a sample value of the output of the circuit; The direction and quality input for the succession of sub-bits in the decoding of the super-bits. and means for combining indicators. 37. 37. The invention according to claim 35 and 36, wherein each of the super bits is one represented by a constant number of subbits, and the correlation output for said superbit is Direction and quality for a segment of length equal to the length of a given number of subbits The invention is characterized in that each subpit is determined from an indicator. 38. 38. The invention according to claim 37, wherein the correlation regarding the super pit is Matching indicator for each subbit in the subbit segment determined by distributing the total of data and quality indicators, and A switching indicator indicates a specific sequence of said subbits and said segment. is determined by comparing the actual sub-bit values invention. 39. The invention according to claim 38, wherein the correlation output for the superbit is The received pattern of the spread spectrum signal represents one super pit. has a range of values indicating the probability of being one of a particular sequence of pupits. , the decoding of the super pit is a correlation output regarding the super bit. When the correlation output exceeds the threshold, start the super bit tracker, and of superbits per interval of superbit length following detection of The invention is characterized in that it is made by sampling correlation output. 40. Claim 12, 13, 15, 16, 25, 26, 28, 29, 35 or 3 6. The invention according to 6, wherein the spread spectrum signal is transmitted at an RF frequency. An invention characterized by: 41. The invention according to claim 25 or 26, wherein the forward and reverse change signals The signal is characterized in that it is generated by a direct sequence of forward and backward changes. invention. 42. A method of transmitting data over a communication line, the method comprising: transmitting data over a communication line, the method comprising: receiving a series of digital signals for transmission over said communication line; and generating a direct sequence of chips; a reverse direction of the direct sequence to represent different values of the digital signal; code the digital signal using the directional sequence and the direct sequence; the step of transmitting the direct and reverse sequences via the communication signal; A method characterized by: 43. A device for transmitting data over a communication channel, the device comprising: A series of digital signals having at least two possible values is transmitted to said communication channel. means for receiving for transmission via; means for generating a direct sequence consisting of a plurality of chips; is said digital by means of a reverse order sequence having a reverse order and said direct sequence. means for coding the digital signal to represent different values of the digital signal; means for transmitting the direct and reverse order sequences via the transmission channel; A device characterized by comprising: 44. The invention according to claim 42 or 43, wherein the direct and reverse order sequence The modulated carrier signal is used to modulate the carrier signal. A signal is transmitted back over said communication channel. 45. 44. The invention according to claim 42 or 43, wherein the direct and reverse order sequences The frequency approximation waveform is such that a continuous square wave is formed by the tip. , the pulse width of the square wave spans the plurality of chips, and the frequency of the square wave is equal to the frequency of the square wave. In at least part of the sequence, the forward change sequence has a low frequency from high frequency to high frequency, and from high frequency to low frequency in reverse change sequence. An invention characterized by gradual changes. 46. The invention according to claim 42 or 43, wherein the direct sequence and the reverse order Each number sequence has a certain spectrum, and the energy within said spectrum is - is within a certain passband. 47. 44. The invention according to claim 42 or 43, wherein the direct sequence and the An invention characterized in that the reverse order sequence is transmitted directly without carrier modulation . 48. 48. The invention of claim 47, wherein the direct sequence and the reverse sequence An invention characterized in that the power is transmitted via a power line. 49. 45. The invention according to claim 44, wherein the modulated carrier signal is in an RF frequency range. An invention characterized by being surrounded by 50. Coding data using forward and backward versions of direct sequences Receiving and transmitting data in a method that transmits data by and decoding method, wherein the transmitted signal is in the forward and reverse directions of the direct sequence. a sequence of spread spectrum signals corresponding to the version; receiving the sequence of spread spectrum signals; a forward output representative of the correlation of the received signal to the forward sequence; and a forward output representing the correlation of the received signal to the forward sequence; A function that produces a reverse direction output representing the correlation of the received signal to the direction sequence. passing the received signal through a correlation circuit that has The received signal is decoded using the correlation output to obtain the coded signal at the transmitter. and restoring digital data. 51. Coding data using forward and backward versions of direct sequences and the transmitted signal corresponds to the forward and reverse versions. Receiving and transmitting data with a sequence of spread spectrum signals A decoding device, means for receiving the sequence of spread spectrum signals; receiving a sequence of system signals and correlating the received signal with the forward sequence; and a correlation of the received signal to the reverse sequence. a correlation circuit configured to generate a reverse output; The forward and reverse correlation outputs are used to decode the received signal and transmit it to the transmitter. a decoder for restoring digital data coded by A device used as a sign. 52. The invention according to claim 50 or 51, wherein the received signal is connected to the correlation circuit. The invention is characterized in that the invention is demodulated using a carrier signal before being supplied to the carrier. 53. 52. The invention according to claim 50 or 51, wherein the correlation circuit a forward matching filter that detects the direct sequence; and a forward matching filter that detects the direct sequence; and a backward matching filter that detects The forward matching filter is a mirror image of the backward matching filter. And, The forward and backward matching filters share the same shift register. An invention characterized by. 54. 54. The invention according to claim 53, wherein the correlation circuit includes four matching filters. and for each of said forward and reverse sequences, The invention is characterized in that 0 degree and 90 degree phase sections are provided. 55. 55. The invention of claim 54, wherein approximately half the taps of the shift register are assigned to the 0 degree phase section and the remaining taps are assigned to the 90 degree phase section. assigned to the Each of the taps assigned to the 0 degree phase section and the 90 degree phase section Two additional group taps are provided for each tap assigned to the and one of these has the same value of the forward and backward sequences. groups and differences with opposite values for the forward and backward sequences group, and each of these four groups is accumulated to give a common accumulation of 0 degrees. forming a value, a 0 degree difference cumulative value, a 90 degree common cumulative value and a 90 degree difference cumulative value; The output of each of the four filter sections is the corresponding common and accumulated value combination. An invention characterized in that it is formed by merging. 56. The invention according to claim 55, wherein the corresponding common and difference accumulated values are The step of combining the common and difference accumulated values in the forward and backward sequences. a step of adding for either one of said sequences and a step of adding for either one of said sequences; an invention characterized in that it has a step of subtracting common and different accumulated values. . 57. The invention according to claim 15 or 16, wherein the forward direction and reverse direction change signals a matching filter for receiving the signal; and the matching filter for receiving the signal. The receiver further includes a receiver that performs independent tracking to accommodate the difference at the timing shown. An invention characterized by: