JP3711429B2 - Spread spectrum communication equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a spread spectrum communication apparatus, and more particularly to a configuration of a communication system when a plurality of modulated signals are multiplexed and transmitted in order to improve communication speed.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a spread spectrum communication system that is resistant to noise and has excellent secrecy has been attracting attention, and development of a transceiver using this communication system is underway. In the spread spectrum communication system, on the transmission side, a transmission data string is modulated by a predetermined spread code (a pseudo noise code sequence, a GOLD code sequence, etc.) output from a spread code generator and transmitted as a spread spectrum signal. On the receiving side, a received data string is obtained by demodulating with the same spreading code as that on the transmitting side synchronized with the received spread spectrum signal.
[0003]
In recent years, the spread spectrum communication method has been attracting attention as a communication method such as a wireless LAN (Local area network) capable of communicating even in a poor communication environment such as a factory or an office, and a frequency of 2.4 to 2.5 GHz. Development of a low-power data communication system in the band ((ISM band) is underway. In particular, for a wireless LAN protocol using a spread spectrum communication method, a physical layer and medium access control (Medium Access Control, hereinafter referred to as MAC). The movement toward standardization is progressing, such as deliberation in the working group 11 (IEEE802.11) of the IEEE802 standardization committee centering on the sublayer.
[0004]
In the spread spectrum communication system as described above, there is a problem that if the symbol rate of the transmission data is increased in order to improve the data transmission speed, the spread ratio cannot be obtained. Therefore, a plurality of spread codes orthogonal to each other are used. A method of improving information transmission speed by multiplexing is employed. This multiplexed transmission method is disclosed in, for example, Japanese Patent Laid-Open No. 7-154365.
[0005]
FIG. 10 is a schematic block diagram showing a configuration of a transmitter of a spread spectrum communication system that employs the above-described multiplexed transmission method. A transmission data string as binary serial data is input to the input terminal 1 and converted into parallel data composed of three parallel signals in the serial-parallel conversion circuit 3. The three data signals divided by the conversion to parallel data are respectively converted into a first spreading code generator 7, a second spreading code generator 8, and a third spreading code generator in multipliers 4, 5, and 6, respectively. 9 is multiplied by the first spreading code, the second spreading code, and the third spreading code given from 9. Each spreading code is a binary pseudo-random sequence and a pulse train faster than the transmission data. Thereafter, the output of these multipliers 4, 5, 6 modulates the carrier wave output from the local oscillators 13, 34, 36 at the modulators 12, 33, 35. The outputs of the modulators 12, 33 and 35 are added by an adder 37. In the case of performing wireless communication, the added signal is converted into a predetermined frequency band propagating in space by the frequency converter 14, amplified by the amplifier 15, and transmitted by the antenna 16.
[0006]
FIG. 11 shows a schematic configuration of a receiver for receiving data transmitted by the transmitter shown in FIG. The signal received by the antenna 22 is amplified by the amplifier 23 and then converted to an intermediate frequency by the frequency converter 24. This intermediate frequency signal is input to the mixer 25 together with the carrier wave output from the local oscillator 26 and converted into a baseband signal. The baseband signal is branched into three and inputted to the three multipliers 27, 38, and 43, respectively, and the first spreading code and the second spreading code outputted from the same first spreading code generator 28 as described above. The second spread code output from the code generator 39 and the third spread code output from the third spread code generator 44 are multiplied and demodulated to obtain three data signals. Each of the supplied first spreading code, second spreading code, and third spreading code needs to have the same phase as the received signal in the pseudo-random sequence. For this purpose, the outputs of the multipliers 27, 38, 43 are respectively input to the integrators 29, 40, 45 and integrated over one symbol duration of each data signal. The phases of the spread code generators 28, 39, and 44 are controlled so that the amplitude of the integrated output is maximized. The outputs of the integrators 27, 38, 43 are determined by the discriminators 31, 42, 47 as to whether the signal amplitude is positive or negative, and a data signal that is a binary signal is output. These three data signals are converted into serial data by the parallel-serial conversion circuit 200, and a final received data string is output from the output terminal 201. Note that the number of multiplexed spread spectrum signals is not limited to 3 and can be set to various numbers.
[0007]
In the above communication, the IEEE 802.11 DSSS (Direct Sequence Spread Spectrum) system is designed to perform transmission and reception in a data format 50 as shown in FIG. A PLCP (Physical Layer Convergence Procedure) preamble A (144 bits) shown in the figure is a data portion for synchronizing at the time of reading. The PLCP header B includes a SIGNAL part b1 ((8 bits) indicating a modulation method, a SERVICE part b2 (8 bits) which is normally not used, a LENGTH part b3 (16 bits) indicating a data transmission time t, and The CRC part b4 (16 bits) indicating the numerical value for the cyclic redundancy check of these preceding data parts, and the MPDU (MAC Protocol Data Unit) data string C is the medium access control (MAC) A data unit used for a communication data protocol.
[0008]
[Problems to be solved by the invention]
As described above, in the multiplexed spread spectrum communication method, since the amount of information corresponding to the number of multiplexing can be transmitted simultaneously, there is an advantage that the information transmission speed can be improved, but the transmitted information is There is a problem that the remainder is generated. For example, as shown in FIGS. 12A to 12C, in a QPSK (Quadrature Phase Shift Keying) modulation method capable of transmitting information of 2 bits per symbol transmitted in a predetermined time Δt, multiplexing is performed as described above. When the number is 3, 6-bit information can be transferred per symbol, and 12 bits can be transmitted for 2 symbols, and 18-bit information can be transmitted for 3 symbols. However, as shown in FIG. 12 (c), if a valid data string including information desired to be transmitted from the transmission side is 16 bits (= 2 bytes, indicated by the hatched portion in the figure), data of 3 symbols In this case, two bits are left and the data is transmitted at the same time.Normally, since the receiving side takes in data every symbol, when receiving three symbols of data, However, when the data is fetched for the third time, unnecessary data is included in 2 bits, so when the data format 50 is transmitted / received, for example, An unnecessary data string X exists in the last part, but the LENGTH part b3 in the PLCP header B has a transmission time t = mΔt (the number m of symbols described above). For example, in the case of FIG. 12 (c), only 3Δt) is described, so when converted from the transmission time to the number of received bits, unnecessary data X is included. There is a problem in that the presence / absence of the data and the amount of unnecessary data X cannot be known, and the transmission / reception data string cannot be received accurately.
[0009]
Therefore, the present invention solves the above-mentioned problems, and the problem is that, in a multiplexed spread spectrum communication system, an always effective transmission / reception data sequence is accurately exchanged regardless of the number of multiplexing and the amount of transmission / reception data. It is an object of the present invention to provide a spread spectrum communication apparatus that can perform the above.
[0010]
[Means for Solving the Problems]
The means taken by the present invention to solve the above problems is that, on the transmission side, each modulation signal is formed by dividing a transmission data string into a plurality of data signals and modulating each data signal with a different spreading code. Are combined and output as a multiplexed spread spectrum signal. On the receiving side, the spread spectrum signal is branched and demodulated by the same different spread codes as described above to extract a plurality of data signals. In a spread spectrum communication apparatus configured to obtain a received data sequence based on the data signals, the transmitting side determines the amount of data that can directly or indirectly specify an effective data sequence to be transmitted. Means for calculating and adding to the transmission data sequence; on the receiving side, the added data included in the reception data sequence; And having a means for retrieving a valid data string from the received data sequence read out.
[0011]
According to this means, since an amount of data that can directly or indirectly specify an effective data string to be transmitted is added to the transmission data string, an effective data string can be specified based on the data amount. Because it becomes possible, it is possible to read the data amount from the received data sequence and extract the valid data sequence from the received data sequence, so that the valid data sequence is always exchanged regardless of the number of multiplexed data and the amount of transmitted / received data. be able to.
[0012]
The transmission data string can be divided into a plurality of data signals or a reception data string can be formed based on a plurality of data signals by, for example, serial-parallel conversion or parallel-serial conversion.
[0013]
Here, the transmission data string is divided into a plurality of data signals, and each modulation signal obtained by modulating each data signal with a different spreading code is combined and output as a multiplexed spread spectrum signal. The spread spectrum signal communication apparatus configured includes means for calculating a data amount that can directly or indirectly specify an effective data sequence to be transmitted and adding the calculated data amount to the transmission data sequence. .
[0014]
The received multiplexed spread spectrum signal is branched and demodulated by different spreading codes to extract a plurality of data signals, and a received data string is obtained based on the plurality of data signals. In the spread spectrum communication apparatus, there is provided means for reading out an effective data string from the received data string by reading out a data amount added to the received data string that can directly or indirectly specify an effective data string. It is characterized by.
[0015]
In each of the above means, the data amount may indicate an effective data amount in the transmission data string or the reception data string. In this case, unnecessary data can be eliminated by sequentially extracting the data amount from the received data sequence by indicating the data amount of the data sequence in which the data amount is valid.
[0016]
In each of the above means, the data amount may indicate an invalid data amount other than a valid data sequence in the transmission data sequence or the reception data sequence. In this case, only the invalid data can be removed from the received data string by indicating the invalid data amount.
[0017]
Further, in each of the above means, the data amount indicates a part of the effective data amount in the transmission data sequence or the reception data sequence, and the effective data amount is determined based on a predetermined data format. The data string may be data that can be calculated. In this case, an effective data string can be calculated from the data amount based on a predetermined data format. For example, when certain predetermined information is described in a predetermined range in the received data string, the range of effective data string in the predetermined information is indicated by the data amount indicating the effective data amount in the predetermined information. And invalid data strings can be identified.
[0018]
The transmitter / receiver according to claim 1, wherein the spread spectrum signal is formed from the transmission data string and transmitted in a predetermined transmission form, and the reception data string is formed from the spread spectrum signal received in the transmission form. And a processing device for adding the data amount to the transmission data sequence and extracting an effective data sequence from the received data sequence based on the data amount. According to this means, by comprising a transceiver and a processing device, a process for adding a data amount to a transmission data string or extracting valid data from a reception data string is processed separately from the transmission / reception process. It can be done flexibly with the device. For example, since the format of the transmission / reception data, the position and content of the data amount, and the like can be appropriately set in the processing device, it can be appropriately handled according to the system.
[0019]
According to a second aspect of the present invention, a transmitter for forming the spread spectrum signal from the transmission data sequence and transmitting the spread spectrum signal in a predetermined transmission form, and a processing device for adding the data amount to the transmission data sequence are provided. It is preferable.
[0020]
According to a third aspect of the present invention, there is provided a receiver for receiving the spread spectrum signal in a predetermined transmission form to form the received data string, and for extracting an effective data string from the received data string based on the data amount. It is preferable to provide the processing apparatus.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of a spread spectrum communication apparatus according to the present invention will be described with reference to the accompanying drawings. First, an outline of a hardware configuration of a spread spectrum communication apparatus for realizing each embodiment described below will be described. FIG. 1 is a schematic configuration block diagram showing a schematic configuration of a spread spectrum communication apparatus. A transceiver 62 is connected to the antenna 61. Within the transceiver 62, there are a transmission / reception circuit unit 62A including an amplification circuit and a frequency conversion unit for amplifying transmission signals and reception signals, and a transmission / reception circuit unit 62A. The same processing as that described with reference to FIG. 10 is performed based on the received signal, and the same processing as that described with reference to FIG. 11 is performed on data sent from the transmission / reception buffer 65 described later. And an S spread signal processing circuit unit 62B configured to perform transmission / reception processing relating to the spread spectrum signal.
[0022]
The transmission / reception circuit unit 62A and the S spread signal processing circuit unit 62B basically include all the components shown in FIGS. 10 and 11 described in the conventional example and are processed in the same manner. Is omitted. The S spread signal processing circuit unit 62B further calculates and confirms a CRC value for cyclic redundancy check related to the PLCP header of transmission / reception data, and calculates description data of the LENGTH unit indicating the transmission time t in the PLCP header of transmission / reception data. In addition, capture data, creation of PLCP header and synthesis with MPDU, and creation of transmission data are also executed.
[0023]
The transmitter / receiver 62 is connected to a transmitter / receiver controller 64 for controlling the S spread signal processing circuit unit 62B and calculating and confirming the CRC value of the MPDU data string. The transmitter / receiver is composed of a RAM (Random Access Memory) or the like. A buffer (or register) 65 is also connected. The transmission / reception controller 64 is connected to a central processing unit (CPU) for controlling the entire apparatus, a ROM (read only memory) connected to the central processing unit, a microprocessor unit (MPU) 66 incorporating a RAM and the like. . This microprocessor unit 66 controls the entire spread spectrum communication apparatus, manages functions directly related to communication such as communication environment setting and spread code setting, and exchanges transmission / reception data with external apparatuses. It comes to manage. The microprocessor unit 66 is connected to a communication dedicated ROM 67 for storing a communication-related program, and stores a transmission program and a reception program which will be described later. The microprocessor unit 66 is connected to an input / output port 68 for exchanging data with an external device.
[0024]
The transmission / reception buffer 65 is connected to the transceiver 62, the transmission / reception controller 64, the microprocessor unit 66, and the input / output port 68. An external device such as a personal computer 70 is connected to the input / output port 68.
[0025]
Next, a first embodiment of the present invention realized by the above configuration will be described. FIG. 2A shows a data processing procedure at the time of data transmission according to this embodiment, and FIG. 2B shows a data processing procedure at the time of data reception according to this embodiment. FIG. 3 shows a data format 81 of transmission / reception data transmitted / received in the present apparatus. In this data format 81, the schematic configuration of the PLCP preamble A, the PLCP header B, and the MPDU data string C is the same as the data format 50 defined by the standard protocol. However, in the LENGTH part b3 in the PLCP header B, the transmission time t was described in the LENGTH part of the standard protocol, whereas in the LENGTH part b3 in the data format 81, the number of bytes of the actual transmission data string (Transmission data is formed in units of bytes) is different.
[0026]
At the time of data transmission, the microprocessor unit 66 calls a transmission program from the ROM 67 and executes the procedure shown in FIG. 2A based on this transmission program. First, the number n of bytes of data to be transmitted (corresponding to the MPDU data string C in the data format 81) is calculated and recorded in the LENGTH part b3 to create a transmission data string by the data format 81 This is stored in the transmission / reception buffer 65. The transmission data stored in the transmission / reception buffer 65 is transferred to the transmitter / receiver 62 by the transmission / reception controller 64 and transmitted from the antenna 61 as a spread spectrum signal as described above.
[0027]
On the other hand, at the time of data reception, a signal received by the antenna 61 under the control of the transmission / reception controller 64 is converted into a reception data string by the transmitter / receiver 62 and stored in the transmission / reception buffer 65. When the microprocessor unit 66 confirms the presence of the reception data string based on the reception program read from the ROM 67, as shown in FIG. 2B, the number n of bytes of the reception data string from the LENGTH part b3. Is obtained, and then the CRC value of the received data string is confirmed. If the CRC value of the received data string is appropriate, the MPDU data string C is fetched from the beginning of the MPDU by the acquired number of bytes n, and the MPDU data string C0 at the time of transmission not including the unnecessary data string X shown in FIG. This is secured in the transmission / reception buffer 65 as regular reception data.
[0028]
Next, a second embodiment according to the present invention will be described with reference to FIGS. In this embodiment, transmission data is composed of the data format 82 shown in FIG. 4A, and the PLCP preamble A and PLCP header B are the same as the standardized data format 50. Therefore, the transmission time t = mΔt of the MPDU data string C is described in the LENGTH part b3 in the PLCP header B.
[0029]
In the transmission data of this embodiment, as shown in FIG. 4B, an unnecessary LENGTH section c2 describing the number of bits Y of the unnecessary data string X is provided next to the MPDU header c1 in the MPDU data string C. . The BODY part c3 is a main body of data to be transmitted, and the CRC part c4 is a part describing a CRC value for cyclic redundancy check of the MPDU data string C. Here, the unnecessary LENGTH part c2 may be arranged at the head position of the MPDU data string C as shown in FIG.
[0030]
In the present embodiment, at the time of signal transmission, as shown in FIG. 5, the microprocessor unit 66 sets the data format for transmission to the one shown in FIG. Select whether to use the one shown in c). In this selection procedure, the program is automatically selected based on setting information in a register set in advance from the outside. Next, the total number of bytes L of the MPDU data string C to be transmitted is calculated. Then, the number of bits Y of the unnecessary data string X is calculated by the following formula based on the total number L of MPDU bytes, the number d of spread spectrum communication multiplexing, and the number of bits s that can be transmitted in one symbol.
[0031]
Y = 8L mod (ds) (1)
If this number of bits Y is 0, there is no unnecessary data string X, so K = 0 is set in the surplus bit description part of the unnecessary LENGTH part c2. If the number of bits Y is not 0, K = Y is set in the remainder bit description part of the unnecessary LENGTH part c2. Next, the transmission time t is calculated from the number of bytes L of the MPDU data string C and the transmission speed, and recorded in the transmission time description part in the MPDU header c1.
[0032]
Finally, the data content to be transmitted is formatted as shown in FIG. 4B or 4C to form the MPDU data string C, and the CRC value for cyclic redundancy check of the MPDU data string C is calculated. Set in CRC part c4. The S-spread signal processing circuit unit 62B creates the PLCP preamble A and PLCP header B shown in FIG. 4A, calculates CRC values for the cyclic redundancy check of the PLCP while transferring them to the transmitter / receiver 62, and similarly transmits / receives them. Transfer to machine 62. Subsequently, the MPDU data string C is transferred from the transmission / reception buffer 65 to the transmission / reception unit 62. The transferred transmission data is transmitted from the antenna 61 as a spread spectrum signal as described above in the transceiver 62.
[0033]
On the other hand, at the time of signal reception, when receiving data is received from the transmitter / receiver 62, the transmitter / receiver 62 checks the CRC part b4 of the PCLP, and if the received data is good, sets the received data string in the transmission / reception buffer 65. . When the reception data string is set, the microprocessor unit 66 starts processing by the transmission / reception controller 64 based on the reception program. The transmission / reception controller 64 first extracts the MPDU data string C from the received data, and further extracts the value of K in the surplus bit description part therein. Next, when the value of K is not 0, the tail of the MPDU data string C is deleted by the number of surplus bits indicated by the value of K. If the value of K is 0, the process proceeds without processing. Next, when the CRC part c4 of the MPDU data string C is checked and the data is appropriate, the microprocessor unit 66 performs transfer of the received data to the recording device and other received data processing. When the processing of the received data is completed, the received data in the transmission / reception buffer 65 is deleted.
[0034]
Finally, a third embodiment according to the present invention will be described with reference to FIGS. FIG. 7 shows a data format 83 of data transmitted and received by the spread spectrum communication apparatus of this embodiment. In this data format 83, as shown in FIG. 7 (a), a P-CRC part D describing a CRC value for PCLP cyclic redundancy check is provided next to the PLCP preamble A and the PLCP header B, and then The MPDU data string C is arranged in FIG. In the MPDU data string C, as shown in FIG. 4B, the MPDU header c1, the M-LENGTH part c2 describing the number of bytes of the BODY part c3 for storing the data body, the BODY part c3, and the MPDU data string An M-CRC unit c4 describing a CRC value for cyclic redundancy check of C valid data is arranged in order. After the M-CRC part c4, an unnecessary data string X is arranged when the above-described surplus bits exist. As shown in FIG. 7C, the M-LENGTH section c2 may be arranged before the MPDU header c1.
[0035]
The data processing procedure at the time of signal transmission in this embodiment is shown in FIG. First, as in the previous embodiment, whether to adopt the MPDU data format shown in FIG. 7B or the MPDU data format shown in FIG. 7C is set to a value set in the register. Select accordingly. Next, the number of bytes of the BODY part c3 shown in FIG. 7B or FIG. 7C in the transmission data is calculated. Next, this number of bytes is set as the value of the M-LENGTH section c2 of the MPDU data string C to form the MPDU data string C, and further, after calculating the CRC value for the cyclic redundancy check of the MPDU data string C , A CRC value is set in the MPDU data string C. Next, the transmission time t is calculated based on the number of bytes of the MPDU data string C and the transmission rate, and set in the MPDU header c1. Next, a transmission data sequence including a PLCP preamble A and a PLCP header B is created and transferred to the transmitter / receiver 62. While transferring, the CRC value for the cyclic redundancy check of the PLCP is obtained and set and transferred. The MPDU data string C is transferred from the transmission / reception buffer 65. Processing and transmission in the transceiver 62 are performed in the same manner as in the above embodiment.
[0036]
On the other hand, at the time of signal reception in this embodiment, when reception data is sent from the transmitter / receiver 62, the transmission / reception controller 64 reads the PLCP CRC value from the P-CRC part D in the reception data string and confirms the PLCP data. If there is no problem, the reception data string is set in the transmission / reception buffer 65. Next, the MPDU data sequence C is extracted from the received data sequence, the number of bytes of the M-LENGTH unit c2 is read, and the BODY unit c3 is selected and extracted by this number of bytes. Next, the CRC value of the MPDU is read to determine whether the data is good or bad. If the data is appropriate, the microprocessor unit 66 performs processing of the received data string such as data transfer and conversion. When the processing of the reception data string is completed, the reception data stored in the transmission / reception buffer 65 is deleted.
[0037]
Among the embodiments described above, in the first embodiment, in place of the transmission time t described in the PLCP header, the number of bytes indicating the effective data amount in the data string to be transmitted is transmitted at the time of transmission. It is described, and it is possible to extract the data portion that has been truly transmitted from the received data based on the number of bytes described in the received data at the time of reception.
[0038]
In the second embodiment, the number of surplus bits in the transmission data is described in the transmission data at the time of transmission, an unnecessary data string is specified by reading out the number of surplus bits at the time of reception, and this is deleted. It makes it possible to retrieve the valid data part that has been transmitted truly.
[0039]
In the third embodiment, the number of bytes of the effective data part of the BODY portion in the MPDU data sequence is described in the MPDU data sequence at the time of transmission, and the MPDU data sequence is read by reading this number of bytes at the time of reception. It is possible to retrieve the valid data portion of the. In this case, a surplus bit indicating invalid data may be described instead of the number of bytes of the valid data portion.
[0040]
In each of the above embodiments, the number of bytes of the valid data portion or the number of surplus bits of the invalid data portion in the transmission data is described, and this is read at the time of reception to extract the valid data portion of the received data. However, the data corresponding to the transmission time (but not the actual transmission time) can be used as long as the information can identify the valid part in the received data, even if it is not the number of bytes or bits. In the case of transmitting an effective amount of data, it is described in a form that can include fractions of less than one symbol.), And the amount of data indicated by an arbitrary unit other than the number of bytes and the number of bits Good.
[0041]
Further, the number of multiplexing in the spread spectrum communication is not limited to that in the above embodiment. Furthermore, it is good also as a device structure only for transmission and reception. In the above embodiment, data processing is executed by the microprocessor unit 66 and the transmission / reception controller 64. However, any form of such a processing device may be used. For example, processing is performed only by a processing device such as a microprocessor unit. Alternatively, processing may be performed only with a predetermined dedicated circuit.
[0042]
As described above, according to the present invention, since the data amount is added to the transmission data sequence, it is possible to specify an effective data sequence based on the data amount, so that the data amount is read from the received data sequence. Since an effective data string can be extracted from the received data string, an effective data string can always be exchanged regardless of the number of multiplexed data and the amount of transmitted / received data.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram showing an outline of a hardware configuration of a spread spectrum communication apparatus according to the present invention.
FIG. 2 is a schematic flowchart (a) showing a processing procedure along a transmission program executed in the first embodiment according to the present invention and a schematic flowchart (b) showing a processing procedure along a reception program.
FIG. 3 is a diagram showing a data format of transmission / reception data in the first embodiment.
FIG. 4 is a diagram (a) to ((c)) showing a data format of transmission / reception data in the second embodiment.
FIG. 5 is a schematic flowchart showing a processing procedure according to a transmission program in the second embodiment.
FIG. 6 is a schematic flowchart showing a processing procedure according to a reception program in the second embodiment.
FIG. 7 is a diagram (a) to ((c)) showing a data format of transmission / reception data in the third embodiment.
FIG. 8 is a schematic flowchart showing a processing procedure according to a transmission program in the third embodiment.
FIG. 9 is a schematic flowchart showing a processing procedure according to a reception program in the third embodiment.
FIG. 10 is a schematic configuration diagram showing a configuration of a transmitter in conventional multiplexed spread spectrum communication.
FIG. 11 is a schematic configuration diagram showing a configuration of a receiver in conventional multiplexed spread spectrum communication.
FIG. 12 is a conceptual diagram of transmission / reception data in multiplexed spread spectrum communication.
FIG. 13 is a diagram showing a data format proposed in spread spectrum communication.
[Explanation of symbols]
60 Spread spectrum communication equipment
61 Antenna
62 Transceiver
62A transceiver circuit
62B S spread signal processing circuit section
64 Transmission / reception controller
65 Transmission / reception buffer
66 Microprocessor unit
67 Communication dedicated ROM
68 I / O ports
A PLCP preamble
B PLCP header
b3 LENGTH part
b4 CRC part
C MPDU data string
c1 MPDU header
c2 M-LENGTH part
c3 BODY section
c4 M-CRC part
DP-CRC part
X Unnecessary data

Claims (6)

On the transmission side, the transmission data string is divided into a plurality of data signals, and each modulation signal obtained by modulating each data signal with a different spreading code is combined and output as a multiplexed spread spectrum signal. On the receiving side, the spread spectrum signal is branched and demodulated by the same different spreading codes as described above to extract a plurality of data signals, and a received data string is obtained based on the plurality of data signals. In the configured spread spectrum communication device,
On the transmission side, it has means for calculating the amount of data that can directly or indirectly specify an effective data string to be transmitted and adding it to the transmission data string,
On the receiving side, it has means for reading out the added data amount included in the received data sequence and extracting an effective data sequence from the received data sequence,
The spread spectrum communication apparatus, wherein the data amount indicates an invalid data amount other than a valid data sequence in the transmission data sequence or the reception data sequence. The transmission data string is divided into a plurality of data signals, and each modulation signal obtained by modulating each data signal with a different spreading code is combined and output as a multiplexed spread spectrum signal. In a spread spectrum signal communication device,
Means for calculating a data amount that can directly or indirectly specify an effective data sequence to be transmitted and adding the calculated data sequence to the transmission data sequence;
The spread spectrum communication apparatus, wherein the data amount indicates an invalid data amount other than a valid data sequence in the transmission data sequence or the reception data sequence. A spectrum configured to branch a received multiplexed spectrum spread signal, demodulate each with a different spreading code, extract a plurality of data signals, and obtain a received data string based on the plurality of data signals In a spread communication device,
Means for reading out an effective data string from the received data string by reading out an amount of data that can be directly or indirectly specified as an effective data string added to the received data string;
The spread spectrum communication apparatus, wherein the data amount indicates an invalid data amount other than a valid data sequence in the transmission data sequence or the reception data sequence. In claim 1,
A transmitter / receiver for forming the spread spectrum signal from the transmission data sequence and transmitting it in a predetermined transmission form and forming the reception data string from the spread spectrum signal received in the transmission form; and A spread spectrum communication apparatus comprising: a processing device for adding the data amount and extracting an effective data sequence from the received data sequence based on the data amount. In claim 2,
A transmitter for forming the spread spectrum signal from the transmission data sequence and transmitting the spread spectrum signal in a predetermined transmission form; and a processing device for adding the data amount to the transmission data sequence. Spread spectrum communication device. In claim 3,
A receiver for receiving the spread spectrum signal in a predetermined transmission form to form the received data string; and a processing device for extracting an effective data string from the received data string based on the data amount. A spread spectrum communication apparatus characterized by the above.

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