JP2008271312A - Radio packet communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio packet communication apparatus capable of performing high-performance transmission of a low packet error rate. <P>SOLUTION: A radio packet communication apparatus comprises a dummy data addition amount determining section 104, which determines the amount of dummy data to be added, according to a determined modulation system and encoding rate, when there is compatibility between transmission and reception; a dummy data adding section 105 which merely adds dummy data by the amount determined by the dummy data addition amount determining section 104; and an original operation information generating section 114 which generates operation information of an original form. The present radio packet communication apparatus transmits, beforehand, the operation information of the original form generated by the original operation information generating section 114 and determines it as being either normal decoding or high-performance decoding, prior to the start of decoding a data signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for realizing a unique operation mode that does not necessarily conform to a standard while maintaining compatibility in a communication system conforming to a standard such as a wireless LAN. As an example of a unique operation mode, when a decoding delay occurs by applying iterative decoding or the like, and the specified time until the reply response (Ack) signal is returned is not in time, an Ack signal that is slower than the specified time by the transmitting and receiving terminals An example of allowing a reply of is assumed.

  In recent years, wireless LANs conforming to the IEEE 802.11 standard have been actively used for computer communication and the like. In the above-mentioned standard, when communication is successful, it is determined that the receiving terminal returns an acknowledgment (Ack: Acknowledgment) signal at a predetermined time (SIFS: Short Interframe Space, 16 μsec) after completion of reception. Yes.

  IEEE 802.11n, which is a high-speed wireless LAN standard, employs a MIMO (Multi-Input Multi-Output) transmission technology that simultaneously transmits and receives a plurality of transmission streams using a plurality of transmission and reception antennas. One technique for improving the reception quality of a MIMO transmission system is to apply iterative decoding that repeats decoding processing of a received signal (see Non-Patent Document 1). In the iterative decoding process, the reception quality can be improved by selecting an appropriate number of iterations.

  In order to obtain a sufficient effect of the iterative decoding process, it is necessary to increase the number of times of iterative decoding. However, if the number of iterations is increased, the processing time also increases, so that the error detection timing for detecting whether communication is successful is delayed. If this error detection timing exceeds the SIFS time, the standards cannot be matched and communication becomes impossible.

  The Ack signal includes a predetermined fixed preamble portion and a signal portion. The preamble part has a time length of 16 μsec and is composed of STS (Short Training Symbol) and LTS (Long Training Symbol). After the preamble portion, as a signal portion, a MAC header and an FCS (Frame Check Sequence) are configured following a symbol indicating a modulation scheme called SIGNAL, a coding rate, and a data length.

  The MAC header part is composed of frame control, duration, and receiving station address. When a signal addressed to itself is transmitted from the first communication station, the terminal that has received the signal (receiving terminal) can return an Ack signal if an error has occurred as a result of error detection by FCS. Without waiting for the packet to be retransmitted. On the other hand, if no error has occurred, the receiving terminal must return an Ack signal to the first communication station. According to the standard, this reply timing is determined when a predetermined time of SIFS has elapsed since the completion of packet reception. The first communication station that should receive the Ack signal, after performing synchronization and channel estimation in the preamble part, determines the signal after the preamble, performs error detection using FCS, and retransmits if there is no error. Without entering the idle state. If an error is detected, or if reception of the Ack signal cannot be confirmed after the SFIS time has elapsed, the first communication station transmits the target packet again.

  Further, the following method is known as a method of returning an Ack signal in consideration of a delay in iterative decoding. That is, the receiving side terminal prepares an Ack signal before completion of iterative decoding, and first starts transmission of the preamble part in the Ack signal when the SIFS time is reached even if error detection by FCS is not completed. deep. The receiving terminal completes the iterative decoding and performs error detection by FCS while transmitting the preamble part in the Ack signal. The receiving terminal continues to transmit the Ack signal as it is when no error is detected. On the other hand, when an error is detected, the receiving station address in the Ack signal is changed to that addressed to the own station, so that the Ack signal is returned in spite of the error and the data is not retransmitted. (See Non-Patent Document 2).

  As another technique for applying iterative decoding processing in a MIMO transmission system, in consideration of delay in iterative decoding, dummy data unrelated to the information signal is added after the information signal, and the delay time due to iterative decoding. Is also known (see Patent Document 1). Since this technique is based on the premise that the receiving terminal can grasp that the dummy data is added, it is necessary to show that it is a unique operation mode by some method.

JP 2006-197045 A "Characteristics of error correction coding MIMO-OFDM using parallel interference canceller", Shibahara, Nishimura, Ogane, Ogawa, IEICE RCS2004-81, IEICE "A Modified Medium Access Control Algorithm for Systems with Iterative Decoding", Inkyu Lee et al., IEEE Trans. On Wireless Communications, vol.5, no.2, Feb. 2006

  According to the technique described in Non-Patent Document 2, even if an error occurs, the preamble portion of the Ack signal that does not need to be transmitted is transmitted, so that a radio channel shared with other terminals is wasted. The transmission efficiency is reduced. In addition, there is a problem that power consumption increases.

  In addition, the above-mentioned Patent Document 1 shows that the content of change processing related to the wireless transmission time of a data signal is added to a control data signal from the viewpoint of maintaining interconnectivity with conventional devices. The configuration is as shown in FIG. However, it is not disclosed how to add the control data at what timing.

  If this control data signal is included in the MAC signal, normal decoding is performed until the MAC signal is decoded, and the content is confirmed when decoding of the control data signal is completed. Although it is necessary to perform control such as switching to high-performance decoding (for example, iterative decoding) if possible, there is no description regarding this control, and it is unclear how to implement it. When the part that controls this switching is implemented, the circuit scale in the control unit increases, and since a high-performance decoding method cannot be used until the control data signal, all signals are decoded by a high-performance decoding method. Compared to this, there is a problem that the probability that an error will occur is high. Further, details are not described on how to transmit the contents of the change processing while maintaining the interconnectivity with the conventional devices.

  The wireless LAN standard IEEE802.11a stipulates that an optimum modulation scheme and coding rate can be selected according to the state of the transmission path. These pieces of information are called MCS (Modulation and Coding Scheme), and information data is decoded according to the MCS. This MCS is transmitted in a symbol encoded with a known and fixed modulation scheme and coding rate called SIGNAL transmitted before the information data. And the information data following SIGNAL will be decoded based on the modulation system and coding rate described in MCS.

  The aforementioned MAC signal is transmitted with symbols after SIGNAL. For this reason, when switching between the normal decoding method and the high-performance decoding method after decoding the MAC header signal, FIFO control that takes into account the synchronization of the decoded data and the like becomes necessary due to the difference in processing delay between the two. The circuit scale is also large and complicated.

  Therefore, it is desirable that it is not necessary to determine whether to apply a high-performance decoding method before decoding information data after SIGNAL, and to switch the decoding method with information data after SIGNAL.

  Therefore, the present invention is configured so that it is possible to decide whether to perform normal decoding processing or high-performance decoding processing before starting decoding of a data signal.

  By the way, as another technique for improving the reception quality of the MIMO transmission system, it is assumed that a redundant antenna is configured so that an appropriate combination of antennas can be selected according to the propagation path condition. If it is assumed that the fluctuation of the propagation path is gradual, it is possible to select the optimal combination when turning on the power, etc., and not change after that, but when the fluctuation of the propagation path is severe, It is desirable to select a combination of antennas for each received packet. That is, it is desirable to perform channel estimation for various combinations of antennas using signals addressed to the own terminal or other terminals transmitted from the access point, and to select a combination having the best reception performance.

  However, the IEEE 802.11 standard presupposes a reception method in which channel characteristics are estimated with a known preamble signal transmitted at the beginning of a packet and a determination is made based on the estimated result. In the communication system, if an operation such as switching the antenna in the middle of a packet is performed, the reception performance is greatly degraded. This will be specifically described below.

  In order to perform propagation path estimation, it is common to use a preamble signal transmitted before a signal in which a destination address is described. In the standard transmission format, since the source address is described in the MAC data located after the preamble signal or the SIGNAL signal, before the preamble signal is transmitted, is the signal addressed to the terminal from the access point, It is impossible to determine whether the signal is for another terminal. In the case of a signal destined for the terminal itself, it is primary to receive with the most suitable antenna combination, and select the antenna combination that is unclear whether it is optimal for the estimation result of the propagation path. If this happens, the reception performance will deteriorate.

  For this reason, in the case of a signal addressed to another terminal, the antenna combinations are switched to perform propagation path estimation corresponding to various combinations, and when a signal addressed to the own terminal is transmitted, an optimum antenna combination is selected. A signal format that can be switched between is required.

  Therefore, the present invention transmits a unique identification signal indicating that the signal is transmitted from the access point at a timing prior to the information data based on the standard, and a signal addressed to another terminal based on the identification signal. When it is determined that there is a channel, a channel estimation measurement for selecting an optimum antenna combination is performed, and the estimation result and the antenna combination are stored in association with each other. When a signal addressed to the terminal is transmitted, the antenna combination having the highest reception performance is selected from the stored correspondences.

  The present invention has been made in view of the above-described conventional circumstances, and an object thereof is to provide a wireless packet communication device that enables high-performance transmission with a low packet error rate. Specifically, the wireless packet communication apparatus that can transmit the operation information of the original form in advance and determine the normal decoding and the high-performance decoding before starting the decoding of the data signal, and the original identification signal An object of the present invention is to provide a wireless packet communication apparatus that transmits data at a timing before data and selects an antenna combination having the highest reception performance.

The first wireless packet communication device according to the present invention performs normal decoding processing or high-performance decoding by transmitting in advance unique operation information such as the contents of change processing related to the wireless transmission time of the data signal. There is an effect that it is possible to determine whether to perform processing before starting decoding of the data signal.
The second wireless packet communication apparatus according to the present invention transmits an original identification signal indicating that the signal is transmitted from an access point at a timing before information data based on the standard, If it is determined that the signal is destined for another terminal based on the signal, a channel estimation measurement is performed to select the optimal antenna combination, and the correspondence between the estimation result and the antenna combination is stored. Keep it. When a signal addressed to the terminal is transmitted, an antenna combination having the highest reception performance can be selected from the stored correspondences.

  In the wireless packet communication device according to the present invention, the wireless packet signal includes information data and transmission information indicating a modulation method and a wireless transmission time of the information data, and the transmission information precedes the information data. A wireless packet communication apparatus to be transmitted, means for adding predetermined data to the information data, means for changing information on the wireless transmission time according to the amount of the predetermined data added, Means for transmitting the contents of the change process before transmitting the information data.

  According to the above configuration, since the operation information in a unique form such as the contents of the change processing related to the wireless transmission time of the data signal is transmitted before the transmission of the information data, for example, information indicating that high-performance decoding means can be adopted. It can be determined before data decoding, and high-performance decoding can be applied to all information data.

  In the radio packet communication apparatus according to the present invention, the means for transmitting the content of the change process transmits the content of the change process using a subcarrier that is not used for transmission of information data.

  According to the above configuration, since the operation information in a unique form such as the contents of the change processing related to the radio transmission time of the data signal is transmitted before the transmission of the information data using the subcarrier not used for the transmission of the information data, It can be determined that the performance decoding means can be adopted before decoding the information data, and high-performance decoding can be applied to all the information data.

  In the wireless packet communication apparatus according to the present invention, the means for transmitting the content of the change process transmits the content of the change process using a plurality of subcarriers that are not used for transmitting information data. .

  According to the above configuration, in order to transmit the operation information in a unique form such as the contents of the change processing related to the wireless transmission time of the data signal before transmitting the information data using a plurality of subcarriers not used for transmitting the information data Therefore, it is possible to determine that high-performance decoding means can be adopted before decoding information data, and high-performance decoding can be applied to all information data.

  In the wireless packet communication apparatus according to the present invention, the means for transmitting the contents of the change processing transmits the subcarriers that are not used for transmission of information data by differential encoding.

  According to the above-described configuration, the operation information in a unique form such as the contents of the change processing related to the wireless transmission time of the data signal is transmitted before the information data is transmitted by differentially encoding the subcarriers not used for transmitting the information data. Therefore, it is possible to determine that high-performance decoding means can be adopted before decoding information data, and high-performance decoding can be applied to all information data.

  The wireless packet communication device according to the present invention includes means for confirming compatibility with a receiving terminal, and the means for adding the predetermined data includes the information data only when the compatibility is present. Predetermined data is added.

  According to the above configuration, predetermined data is added only when there is compatibility with the receiving side terminal, so that the incompatible receiving side terminal does not perform useless processing and consumes useless energy. There is no.

  In the wireless packet communication device according to the present invention, the means for confirming compatibility has a function of transmitting a predetermined sequence using a plurality of subcarriers not used for transmission of information data, This includes a function for recognizing the transmission of a certain sequence and a function for returning a predetermined sequence using a plurality of subcarriers that are not used for transmission of information data.

  According to the above configuration, a predetermined sequence is transmitted using a plurality of subcarriers that are not used for transmission of information data, and compatibility with the receiving terminal is confirmed, so that high-performance decoding means can be employed. It can be determined before decoding the information data, and high-performance decoding can be applied to all the information data.

  In the wireless packet communication device according to the present invention, the wireless packet signal is configured to include information data and transmission information indicating a modulation method and a wireless transmission time of the information data, and the transmission information is more than the information data. A wireless packet communication device transmitted before, wherein the wireless transmission time is described in the first transmission information and the second transmission information, and means for adding predetermined data to the information data; Means for changing information related to the wireless transmission time described in the first transmission information according to the added predetermined data amount, and the second transmission information according to the added predetermined data amount. Means for changing the information relating to the wireless transmission time to be described, and the information relating to the wireless transmission time described in the first transmission information is longer than the time required for the actual wireless transmission It is intended to represent between.

  In the above configuration, it is desirable that the first transmission information is a Length value indicating a packet length described in Legacy-SIGNAL, and the second transmission information is a Length value indicating a packet length described in HT-SIGNAL. .

  In addition, the first transmission information and the second transmission information are divided into a terminal that conforms only to IEEE802.11a waiting while the packet is transmitted in the HT mode, and erroneously starts transmitting the packet. This is to allow a terminal compliant with only IEEE 802.11a to understand the packet transmission period in the HT mode so that interference does not occur.

  In addition, setting the first transmission information to a time longer than the time required for the actual wireless transmission is set to be longer by the data length corresponding to the number of excess delay symbols than the Length value that should originally be described in the Length-SIGNAL. Thus, it can be determined that the difference from the Length value that should originally be described in the Length-SIGNAL is due to the addition of dummy data.

  Therefore, when there is a difference, it is determined that a high-performance decoding method can be used, and all the information data transmitted after HT-SIGNAL can be decoded by the high-performance decoding method. Note that the second transmission information is set to the actual wireless transmission time.

  Thus, the reason why the first transmission information is set longer is that it can be determined that the value is larger than the value that should be originally described. This determination can be made because a terminal capable of receiving the HT mode can uniquely derive the Length value to be described in Legacy-SIGNAL from the Length value described in HT-SIGNAL based on the standard. Because.

  In the wireless packet communication device according to the present invention, the information regarding the wireless transmission time described in the second transmission information is set according to ½ of the added predetermined data amount. .

  According to the above configuration, when the amount of the added predetermined data amount is large, the value becomes large if the amount of the added data amount is shown as it is. Yes.

  In addition, since the amount of added dummy data can be grasped and an allowable processing delay can be grasped, for example, when a high-performance decoding method is iterative decoding, it is possible to increase the number of iterations to an allowable processing delay. High quality reception performance is realized.

  In addition, the wireless packet communication device according to the present invention determines whether a MAC data signal generation unit that converts a signal from an upper layer into a MAC signal is compatible with the reception side according to the result of received signal analysis. The compatibility determination unit, the MCS determination unit that determines the modulation scheme, the coding rate, and the data length according to the result of the received signal analysis, and the compatibility determination unit when the compatibility determination unit determines that the compatibility exists. According to the modulation scheme, coding rate, and data length determined by the MCS determination unit, a dummy data addition amount determination unit that determines a dummy data amount to be added, and an amount determined by the dummy data addition amount determination unit Information indicating that the dummy data is added, a dummy data adding unit that adds dummy data to the MAC signal, an encoding unit that encodes the MAC signal to which the dummy data is added, and A unique operation information generating unit that generates operation information in a specific form, a SIG generating unit that generates a SIGNAL signal according to the modulation scheme, coding rate, and data length determined by the MCS determining unit, and the SIG generating unit A SIG adding unit that adds the SIGNAL signal generated in step 1 before the encoded MAC signal, and a mapping unit that maps both the output signal of the SIG adding unit and the operation information of the unique form according to a predetermined modulation method, respectively. And comprising.

  According to the above-described configuration, for example, high-performance decoding means is used to map the operation information in a unique form such as the contents of the change processing related to the radio transmission time of the data signal in accordance with a predetermined modulation method and transmit the information data before transmission. It is possible to determine that it is possible before decoding information data, and it is possible to apply high-performance decoding to all information data.

  In addition, the wireless packet communication device according to the present invention determines whether a MAC data signal generation unit that converts a signal from an upper layer into a MAC signal is compatible with the reception side according to the result of received signal analysis. The compatibility determination unit, the MCS determination unit that determines the modulation scheme, the coding rate, and the data length according to the result of the received signal analysis, and the compatibility determination unit when the compatibility determination unit determines that the compatibility exists. According to the modulation scheme, coding rate, and data length determined by the MCS determination unit, a dummy data addition amount determination unit that determines a dummy data amount to be added, and an amount determined by the dummy data addition amount determination unit A dummy data adding unit for adding dummy data to the MAC signal; an encoding unit for encoding the MAC signal to which the dummy data is added; and a modulation scheme and code determined by the MCS determining unit. A SIG generation unit that generates a SIGNAL signal according to a conversion rate and a data length, and changes a Length value indicating a packet length described in a Legacy-SIGNAL signal and an HT-SIGNAL signal included in the transmission information, and the SIG generation A SIG adding unit that adds the SIGNAL signal generated by the unit before the encoded MAC signal.

  According to the above configuration, since the Length value of the SIGNAL signal is changed in correspondence with the operation information in a unique form such as the contents of the change processing related to the wireless transmission time of the data signal and transmitted before transmission of the information data, for example, high-performance decoding It is possible to determine that the means can be adopted before decoding the information data, and it is possible to apply high-performance decoding to all the information data.

  In the wireless packet communication device according to the present invention, the wireless packet signal is composed of information data, transmission information describing the modulation method and wireless transmission time of the information data, a known preamble signal for estimating a propagation path, and the like. In the wireless packet communication apparatus in which the preamble signal is transmitted before the information data, whether the terminal that is a communication target is a specification that allows a unique operation mode A means for confirming, a means for giving identification information to each terminal in the case of a specification that allows a unique operation mode, and a means for transmitting the identification information before the information data.

  According to the above configuration, the identification information for each terminal is transmitted at a timing earlier than the information data. For example, the antenna combination having the highest reception performance can be selected before decoding the information data, and all the information data is It can be received with a simple antenna.

  In the wireless packet communication apparatus according to the present invention, the means for transmitting the identification information transmits the identification information using a subcarrier that is not used for transmitting information data.

  According to the above configuration, the identification information for each terminal is transmitted at a timing before the information data using subcarriers that are not used for transmission of the information data. It can be selected before decoding, and all information data can be received by a high-performance antenna.

  In the wireless packet communication apparatus according to the present invention, the means for transmitting the identification information transmits the identification information using a plurality of subcarriers that are not used for transmission of information data.

  According to the above configuration, the identification information for each terminal is transmitted at a timing before the information data using a plurality of subcarriers that are not used for transmission of information data. It can be selected before data decoding, and all information data can be received by a high-performance antenna.

  In the wireless packet communication apparatus according to the present invention, the means for transmitting the identification information transmits the subcarriers that are not used for transmission of information data by differential encoding.

  According to the above configuration, since the subcarriers that do not use identification information for each terminal are differentially encoded and transmitted at a timing before the information data, the antenna combination with the highest reception performance is selected. It can be selected before decoding the information data, and all the information data can be received by a high performance antenna.

  The radio packet communication apparatus according to the present invention includes means for confirming compatibility with a receiving terminal, wherein the means for confirming compatibility uses a plurality of subcarriers not used for transmission of information data. A step of transmitting a predetermined sequence, a step of recognizing that the predetermined sequence is transmitted on the receiving side, and a step of returning the predetermined sequence using a plurality of subcarriers not used for transmission of information data Is included.

  According to the above configuration, since a predetermined sequence is transmitted using a plurality of subcarriers that are not used for transmission of information data and compatibility with the receiving terminal is confirmed, the antenna combination with the highest reception performance is selected. It can be selected before decoding the information data, and all the information data can be received by a high performance antenna.

  In the wireless packet communication device according to the present invention, the wireless packet signal includes information data and transmission information indicating a modulation method and a wireless transmission time of the information data, and the transmission information precedes the information data. The wireless packet communication device is transmitted to the wireless transmission device, wherein the wireless transmission time is described in the first transmission information and the second transmission information, and is described in the first transmission information according to the assigned identification information. Means for changing the information relating to the wireless transmission time to be kept.

  According to the above configuration, since the information about the wireless transmission time described in the first transmission information is changed according to the identification information, for example, the Length value and the identification information (ID) that should originally be described in the Lengthacy-SIGNAL By transmitting the information corresponding to the value differently, it is possible to confirm the identification information in advance before receiving the information data at the receiving terminal.

  Therefore, it is detected whether or not the identification information matches that assigned to the terminal, and if they match, the combination with the best characteristics is selected by the performance indexing of the channel estimation stored for each antenna combination. Since the combination of antennas can be changed before receiving the information data, high-performance reception characteristics can be realized.

  When adding dummy data, the length of the packet is increased by the amount of dummy data added, so the second transmission information needs to be changed. However, if dummy data is not added, the packet length There is no change. Therefore, there is no need to change the second transmission information. Incidentally, since the identification number is superimposed on the transmission information of the wireless packet signal and sent, it does not affect the packet length.

  In addition, the wireless packet communication device according to the present invention determines whether a MAC data signal generation unit that converts a signal from an upper layer into a MAC signal is compatible with the reception side according to the result of received signal analysis. A compatibility determination unit, an identification number assigning unit that assigns an identification number for identifying the reception side when it is determined to be compatible with the reception side, and a modulation scheme and encoding according to the result of the received signal analysis An MCS determination unit that determines a rate and a data length; an encoding unit that encodes the MAC signal; and a SIG that generates a SIGNAL signal according to the modulation scheme, the encoding rate, and the data length determined by the MCS determination unit The generation unit, the SIG addition unit that adds the SIGNAL signal generated by the SIG generation unit before the encoded MAC signal, the output signal of the SIG addition unit, and the identification number are both included. Including a mapping unit for mapping in accordance with a predetermined modulation scheme, respectively.

  According to the above configuration, the identification number for identifying the receiving side is mapped according to a predetermined modulation method and transmitted at a timing before the information data. For example, a combination of antennas having the highest reception performance is decoded before decoding the information data. All information data can be received by a high-performance antenna.

  In addition, the wireless packet communication device according to the present invention determines whether a MAC data signal generation unit that converts a signal from an upper layer into a MAC signal is compatible with the reception side according to the result of received signal analysis. A compatibility determination unit, an identification number assigning unit that assigns an identification number for identifying the reception side when it is determined to be compatible with the reception side, and a modulation scheme and encoding according to the result of the received signal analysis An MCS determination unit that determines a rate and a data length; an encoding unit that encodes the MAC signal; and a SIGNAL signal that is generated according to the modulation scheme, coding rate, and data length determined by the MCS determination unit A SIG generation unit that changes a Length value indicating a packet length described in the Legacy-SIGNAL signal and the HT-SIGNAL signal included in the transmission information, and the SIG generation The SIGNAL signal generated in part including a SIG addition unit that adds the previous coded MAC signal.

  According to the above configuration, since the Length value of the SIGNAL signal is changed in correspondence with the identification number that identifies the receiving side and transmitted at a timing before the information data, for example, the combination of antennas having the highest reception performance is selected as the information data. Can be selected before decoding, and all information data can be received by a high-performance antenna.

  According to the present invention, it is possible to provide a wireless packet communication device that enables high-performance transmission with a low packet error rate. In particular, high-performance decoding is possible by transmitting a signal indicating an original operation form before starting decoding of an information signal, and it is possible to select an optimum antenna combination. Has the effect of enabling efficient transmission.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic block configuration diagram of a radio packet communication apparatus showing the first embodiment. The wireless packet communication apparatus according to the present embodiment is connected to an antenna 501, an analog unit 502 that performs analog / digital conversion of a high-frequency signal, a baseband processing unit 503 that performs baseband processing of transmission / reception data, a reception processing unit 515, It has a MAC processing unit 504 including a reception signal analysis unit 516 and a transmission processing unit 517, and an upper layer processing unit 505. The analog unit 502 includes a switch 511 that switches between transmission and reception, a high-frequency circuit (RF) 512, an A / D conversion unit 513, and a D / A conversion unit 514.

  FIG. 2 is a block configuration diagram of the wireless packet communication apparatus showing the first embodiment. The wireless packet communication apparatus according to the present embodiment responds to a signal from the MAC data signal generation unit 101 that converts a signal from the upper layer processing unit 505 illustrated in FIG. 1 into a MAC signal, and a signal from the reception signal analysis unit 516 illustrated in FIG. Thus, the compatibility determination means 102 for determining whether or not the receiving side can implement this embodiment (i.e., compatibility), and the modulation scheme and encoding according to the signal from the received signal analysis unit 516 shown in FIG. An MCS determination unit 103 that determines the rate is provided.

  In addition, the wireless packet communication apparatus according to the present embodiment determines the dummy data addition amount that determines the dummy data amount to be added according to the modulation scheme, coding rate, and data length determined when transmission and reception are compatible. Unit 104, dummy data addition unit 105 that adds dummy data by the amount determined by dummy data addition amount determination unit 104, and unique operation information generation unit 114 that generates operation information in a unique form.

  The wireless packet communication apparatus according to the present embodiment transmits in advance the operation information in the unique form generated by the unique operation information generation unit 114 and determines whether the normal decoding process or the high-performance decoding process is performed. It is determined before starting decoding. The unique form of operation information is information indicating that dummy data has been added.

  Without this unique form of operation information, it cannot be determined whether or not dummy data is added before decoding the information data. The high-performance decoding means has a large delay, and if the dummy data is not added, it cannot keep up with the standard Ack reply timing, so it cannot be used in a situation where it is uncertain whether the dummy data is added. In other words, if there is no unique form of operation information, it can be recognized that dummy data is added after the reception of the information data is completed, so that it is possible to identify that extra data is added. The high-performance decoding means cannot be applied retroactively at the start of information data reception.

  In addition, the wireless packet communication apparatus according to the present embodiment indicates an encoding unit 106 that encodes a signal to which dummy data is added (or not added), a modulation scheme, a coding rate, a data length, the number of streams, and the like. A SIG generation unit 108 that generates a SIGNAL signal and a SIG addition unit 107 that adds the SIGNAL signal generated by the SIG generation unit 108 before the encoded signal are provided.

  Further, the mapping unit 109 that maps both the output of the SIG addition unit 107 and the dummy data addition amount according to a predetermined modulation method, the output of the IFFT unit 110 that performs IFFT (inverse fast Fourier transform) on the output of the mapping unit 109, and the output of the IFFT unit 110 A GI adding unit 111 that duplicates and adds a predetermined signal, a preamble generating unit 112 that generates a preamble signal to be transmitted before the SIGNAL signal, a preamble adding unit 113 that adds the generated preamble, and the like.

  When adding dummy data according to the present embodiment, it is necessary to confirm compatibility between the transmission side and the reception side in advance. Various specific methods are conceivable. As an example, as shown by hatched lines in FIG. 3, predetermined subcarriers (center carrier 132 or end carriers 131 and 133) not used for signal transmission are shown. , The transmitting side AP (Access Point) differentially encodes and transmits a signal that is a known predetermined sequence (for example, “1010...”).

  Then, the terminal on the receiving side also demodulates the predetermined subcarrier by the delay detection, and when the demodulation result is a known predetermined sequence, the receiving side determines that the AP is compatible, and from the terminal side Similarly, a predetermined subcarrier of a transmission signal (for example, an Ack signal) is differentially encoded in the same manner, and a signal having a known predetermined sequence is transmitted.

  When the AP performs delay detection on a predetermined subcarrier in the received signal and determines that the signal is in a known predetermined sequence, compatibility is confirmed between the transmitting side and the receiving side. As a method for confirming compatibility, it can be assumed that normal information data is used instead of the physical layer as described above.

  The MCS determination unit 103 determines the modulation scheme, the coding rate, the number of streams, and the like that maximize the throughput in the current communication state with reference to the past packet transmission success frequency and the like.

  The MAC data signal generation unit 101 receives data from an upper layer and generates a MAC data signal by adding a predetermined signal. Specifically, the MAC data signal generation unit 101 includes a function of adding or duplicating frame control, address, sequence control, and the like to a frame body that is data from an upper layer.

  A length value indicating the data length of the packet is added to the output from the MAC data signal generation unit 101. The dummy data addition amount determination unit 104 determines how much dummy data should be added from the Length value and the determined MCS value. The amount of dummy data to be added is set so that the amount of transmission data after addition is a multiple of the amount of transmission data per symbol. The amount of transmission data per symbol is uniquely determined by the MCS value. As the number of symbols to be added, delay time exceeding SIFS time is compensated by performing high-performance decoding on the receiving side.

  When the excess delay time is not constant, it is also preferable to inquire the number of excess delay symbols from the transmission side to the reception side at the time of the compatibility check described above. In this case, since the amount of dummy data to be added becomes variable, it is also preferable that the added dummy data amount is included in the transmission signal and shown to the receiving side.

  That is, the number of symbols increased by the addition is output from the dummy data addition amount determination unit 104, mapped by the mapping unit 109 with a predetermined modulation method, and superimposed on the information data.

  As described above, when the mapping unit 109 superimposes, it is possible to transmit the dummy data addition amount using a predetermined subcarrier (center carrier 132 or end carriers 131 and 133) that is not used in normal transmission. It becomes. On the receiving side, it is possible to grasp when a predetermined subcarrier is demodulated without waiting for decoding of the MAC data in order to detect the additional amount of dummy data, and iterative decoding is performed on all data after SIGNAL. It is possible to apply high-performance decoding such as.

  When this additional amount of dummy data is included in the MAC data as in the conventional example, it is impossible to determine whether or not high-performance decoding with a large delay is possible until decoding of the MAC data, and thus normal decoding means must be used. .

  On the other hand, in this embodiment, since the dummy data addition amount is transmitted using the SIGNAL part and the preamble part, high-performance decoding that requires time until the processing delay corresponding to the dummy data addition amount is executed from the beginning. Is possible.

  The dummy data adding unit 105 adds dummy data to the data signal output from the MAC data generating unit 101 by the amount determined by the dummy data addition amount determining unit 104. As the dummy data, a random signal may be used, but usually all bits are fixed to bit 0 or bit 1.

  Encoding section 106 scrambles the signal to which dummy data is added (or not added) and then encodes the signal. As encoding, various schemes such as convolutional encoding, LDPC encoding, and turbo encoding are assumed, but not limited thereto. In the case of convolutional encoding, if part of the dummy data that is the final data is changed using known data called tail bits and then convolutional encoding is performed, the surviving when Viterbi decoding is performed on the receiving side This is preferable because the initial state when searching for a path can be determined and the error rate can be reduced.

  A SIG adding unit 107 is configured following the encoding unit 106. The SIG adding unit 107 adds the SIGNAL signal generated by the SIG generating unit 108 before the encoded signal output from the encoding unit 106.

  In a normal case, the SIG generation unit 108 generates a SIGNAL signal based on the Length value indicating the data length of the packet output from the MAC data signal generation unit 101, and the modulation scheme and coding rate determined by the MCS determination unit 103. Generate. When dummy data is added in the present embodiment, it is necessary to increase the above-described Length value in accordance with the added dummy data addition amount.

  The mapping unit 109 receives a signal from the dummy data addition amount determination unit 104 in addition to the output from the SIG addition unit 107, which is a normal information signal, and performs mapping according to a predetermined modulation method.

  In the IEEE802.11n standard, the SIGNAL part is fixed to BPSK which is the most sensitive modulation system, and the data part after the SIGNAL part is based on the modulation system determined by the MCS determination unit 103. It is necessary to determine a predetermined modulation method for the dummy data addition amount.

  Since subcarriers that transmit dummy data use subcarriers that are not used for transmission of normal information data, it is assumed that channel characteristics cannot be estimated.

  Therefore, it is preferable to use differential modulation (DBPSK, DQPSK, etc.) that does not require channel estimation as the modulation method. The timing for mapping the dummy data addition amount may be either the preamble part or the SIGNAL part as long as it is before the data part, but at least two symbols are required when differential modulation is applied.

  The signal mapped by the mapping unit 109 is input to the IFFT unit 110, and inverse fast Fourier transform is performed by the IFFT unit 110 to convert it into a time axis signal. Thereafter, the guard interval adding unit 111 adds a copy of a predetermined part in the time axis signal to the output from the IFFT unit 110.

  When transmitting the dummy data addition amount using the preamble part, since only the method of adding the guard interval of the LTS signal is different from the method of adding information data, it is necessary to control to switch this.

  The preamble generation unit 112 generates a preamble time axis signal, which is a known signal, and the preamble addition unit 113 adds a preamble signal before the SIGNAL unit. When transmitting the dummy data addition amount also using the preamble part, it is necessary to add the generated preamble signal and the IFFT output.

  Therefore, it is preferable to superimpose only on Legacy-SIGNAL or HT (High Throughput) -SIGNAL because it is not necessary to add a preamble signal and an IFFT output.

  FIG. 4 shows a signal format in the case of an IEEE 802.11n mixed mode (a mode in which backward compatibility is maintained even when an IEEE 802.11a terminal exists). Radio packet signals 201 to 209 include transmission information 203 to 205 and information data 209. Here, the wireless transmission time represents the time required for transmitting the information data 209, that is, the time required for transmitting the information data 209 from the transmitting side to the receiving side. In the standard, not the transmission time but the data length (number of bytes) is described as transmission information.

  In FIG. 4, first, Legacy (same as IEEE802.11a) -STS signal 201 and Legacy-LTS signal 202 which are preamble signals are transmitted, and then Legacy-SIGNAL signal 203 is transmitted. Thereafter, two symbols of HT-SIGNALs 204 and 205 based on the IEEE 802.11n standard are transmitted.

  The length value of Legacy-SIGNAL 203 is set to be a data length that can be transmitted when BPSK of IEEE802.11a and a coding rate of 1/2 are transmitted during the time required for transmission in HT (High-Throughput) mode. It is prescribed to be set to.

  Regarding the Length values of HT-SIGNALs 204 and 205, when the data length is divided by the number of data per symbol determined in accordance with the number of streams, the modulation scheme, and the coding rate determined by the MCS determination unit 103, and is not divisible A value obtained by multiplying the value obtained by adding 1 to the obtained quotient and the number of data per symbol is set. When dummy data is added as in the present embodiment, it is necessary to increase the Length value for both Legacy and HT to accommodate this.

  After SIGNAL 205, HT-STS 206 and HT-LTS signals 207 and 208 are transmitted. FIG. 4 shows a case where the number of streams is 2, and the HT-LTS signals 207 and 208 are 2 symbols.

  As described above, when the timing of transmitting the additional amount of dummy data is the same as that of Legacy and HT SIGNALs 203 to 205, an exception process for adding a guard interval is unnecessary, which is preferable. If 3 symbols are transmitted by the DQPSK method at the timings of Legacy and HT SIGNALs 203 to 205, a 4-bit signal can be transmitted, and 0 to 15 can be designated as an additional amount of dummy data.

  Further, if one bit of the 4 bits is used for parity check, the amount of dummy data added is 0 to 7, which is half, but it is possible to prevent malfunction when an error occurs. is there.

  The added amount of dummy data may be the number of added symbols itself, but the number of added symbols per unit is not limited to one. For example, if the number of additional symbols per unit is 2, even if 1 bit is used for parity check, the number of dummy data symbols that can be specified is 0, 2, 4,. Is suitable.

  As the subcarrier for transmitting the additional amount of dummy data, one of the center carrier 132 and the end carriers 131 and 133 that are not used for transmission of the information signal may be used. Diversity combining is possible, and the probability of transmission errors can be reduced.

  As the transmission method of the number of excess delay symbols, in addition to the method using a predetermined subcarrier that is not used in normal transmission as described above, it is also possible to use the characteristics of the IEEE802.11n mixed mode standard. Conceivable.

  In the mixed mode, the Length value indicating the packet length is described in both Legacy-SIGNAL 203 and HT-SIGNALs 204 and 205. Both packet lengths have a certain relationship defined in the standard. This is to prevent the IEEE802.11a terminal that is only in standby mode from starting a packet transmission accidentally and causing interference while the packet is being transmitted in the HT mode. This is because the terminal compliant only with 11a is made to understand the packet transmission period in the HT mode.

  That is, a terminal that can receive the HT mode can derive the Length value to be described in Legacy-SIGNAL 203 from the Length value described in HT-SIGNAL 204, 205.

  Therefore, if the length of the data corresponding to the number of excess delay symbols is described longer than the Length value that should originally be described in Legacy-SIGNALs 204 and 205, this difference is due to the addition of dummy data. It can be judged. If there is a difference, it is determined that a high-performance decoding method can be used, and all the information data 209 transmitted after HT-SIGNALs 204 and 205 can be decoded by a high-performance decoding method.

  With such a transmission method, a terminal compliant with only IEEE802.11a waits for a time corresponding to the Length value described in Legacy-SIGNAL 203, so that no interference occurs.

  In addition, other terminals that comply with IEEE802.11n and are not operating in the original mode cannot know that dummy data has been added, and therefore wait in accordance with the Length value described in HT-SIGNAL 204, 205. Start sending later.

  Even if the Length value described in the HT-SIGNALs 204 and 205 is left as it is when dummy data is not added, other terminals (not operating in the original mode conforming to IEEE802.11n) can transmit. Transmission will be started before completion, but this is not a problem for the receiving terminal operating in the unique mode because reception of necessary information signals has already been completed.

  FIG. 5 shows a block configuration of the wireless packet communication apparatus when the additional amount of dummy data is transmitted by changing the Length value described in Legacy-SIGNAL 203. The Legacy-Length value is increased by the SIG generation unit 301 by the data length corresponding to the dummy data addition amount determined by the dummy data addition amount determination unit 104.

  In this way, by describing a value that is larger by the added dummy data length, the reception side sets the Length value that is greater by the amount of dummy data added than the Legacy-Length value that can be converted from the HT-Length value. Therefore, it can be determined that the processing delay can be ensured by the additional amount of dummy data.

  For example, when a 1500-byte information signal is transmitted with 2 streams, 16QAM, an encoding rate of 3/4, and a normal guard interval length, when transmitted in HT (High-Throughput) mode, the Legacy-Length value is 1500 bytes. Keep it.

  On the other hand, Legacy-SIGNAL 203 describes a value obtained by converting the time required to complete transmission in the HT mode into BPSK and coding rate 1/2. That is, the standard defines that 3 × ([1500 × 8 ÷ 312] + 2 + 3) −3 = 126 is described. In the present embodiment, when dummy data is added for two symbols, for example, this value is described as 3 × ([1500 × 8 ÷ 312] + 2 + 3 + 2) −3 = 132.

  In this way, it can be determined on the receiving terminal side that dummy data for two symbols has been added, and it can be determined that a demodulation method with a large processing delay such as iterative decoding can be adopted. Here, the value to be described is not limited to the number of symbols of the added dummy data, but may be larger than the value determined by the standard.

  In addition, since the Length value described in Legacy-SIGNAL 203 is longer by the dummy data addition amount than the time when the signal is actually present on the wireless transmission path, the terminal compliant with only IEEE802.11a Although the standby time becomes longer and the throughput of the system slightly deteriorates than when subcarriers that are not used for data transmission are used, it is preferable because the block configuration of the transmission / reception circuit may remain the same as before. is there.

  If the excess delay time is constant, the amount of dummy data added can also be constant, so 1 bit of whether or not dummy data is added is sufficient as information that must be transmitted. It becomes. Therefore, in this 1-bit transmission, it is preferable to use unused bits for SIGNALs 203 to 205 for reservation because there is almost no increase in circuit scale.

  FIG. 6 shows the configuration of the receiving side in the wireless packet communication apparatus of this embodiment. Normal decoding is performed by the determination unit 524 in the previous stage, and high-performance decoding is performed by the determination unit 527 in the subsequent stage. Both of the data signals can be decoded (normal decoding and high-performance decoding), and one of the two is selected. Which one is selected is selected by the decoding method determining means 525 in the figure.

  According to the wireless packet communication device of this embodiment, since the operation information in a unique form such as the contents of the change processing related to the wireless transmission time of the data signal can be received in advance, whether the data signal is normally decoded or high-performance decoded. It can be determined before starting decoding.

(Embodiment 2)
7 and 8 show the configuration of the wireless packet communication apparatus according to the second embodiment of the present invention. In this embodiment, the identification number corresponding to the destination address is sent using the configuration sent as the dummy data addition amount in the first embodiment. That is, the wireless packet communication apparatus of the present embodiment omits the dummy data addition amount determination unit 104, the dummy data addition unit 105, and the unique operation information generation unit 114 shown in FIG. It is. Then, in the case of FIG. 7, the mapping unit 109 superimposes the identification number generated by the identification number assigning unit 115 on the transmission data and transmits it on the subcarrier. On the other hand, in the case of FIG. 8, the generated identification number is supplied to the SIG generation unit 301 to change the data length (Length value) of the packet.

  As an identification number, a MAC address individually defined for each wireless LAN device can be used, but since it is as long as 48 bits, it is necessary to assign it with a small capacity from the access point side when initializing at the time of power-on etc. Is preferred. If the capacity is small, as shown in the first embodiment, the identification number is determined by a transmission method using unused subcarriers or the like, or a method using characteristics of the IEEE 802.11n mixed mode standard. Can be transmitted.

  The access point confirms compatibility when a new terminal joins the subordinate network, and assigns identification information if it is determined to be compatible. If the total number of identification information is 3 bits, it is possible to identify up to 8 terminals, and it is considered sufficient for use in homes and the like.

  The assigned identification information is associated with the MAC address of the receiving terminal, and when a signal to be transmitted is input from an upper layer, the MAC data signal generation unit 101 generates the MAC data and simultaneously grasps the corresponding identification information. To do. Then, the identification information obtained before transmitting the channel estimation preamble signal (LTS) is transmitted by the transmission method described in the first embodiment.

  That is, in the case of the IEEE802.11n mixed mode, since the HT-LTS for channel estimation is transmitted after the SIGNAL signal, the Legacy-STS signal, the Legacy-HTS signal, the Legacy-SIGNAL signal, and the HT-SIGNAL. When transmitting a signal, HT-STS, etc., an identification signal (a signal indicating identification information) can be superimposed and transmitted on a center subcarrier that is not used, a subcarrier at the end of the band, or the like (see FIG. 7). ).

  It is also possible to transmit the identification information in correspondence with the difference between the Legacy-SIGNal Length length and the original Legacy-Length length obtained from the HT-SIGNal Length length (see FIG. 8).

  Here, characteristics in MIMO communication in which a plurality of streams are transmitted simultaneously will be considered. Even if there is a sufficient reception level in MIMO communication, there is a situation in which interference between streams is large and difficult to separate depending on the state of the propagation path. In such a case, it is desirable that a redundant antenna is prepared and an optimum propagation path with small interference between streams is selected by changing the combination of antennas.

  In order to select a combination of antennas, when the received identification information is different from the identification information of its own terminal, the receiving side sequentially changes the antenna combinations for each packet and measures the propagation path in advance. An index of received performance is stored for each antenna combination. If the identification information is addressed to the own terminal, the antenna combination having the highest reception performance is selected.

  For example, as shown in FIG. 9, in a network composed of an access point 601, a terminal A602, and a terminal B603, the terminal A602 receives a packet addressed to the terminal B603 (the received identification information is the identification information of its own terminal). If the antenna combination is different, the combination of antennas to be selected is sequentially changed.

For example, when six antennas are configured in a receiving apparatus having three RF systems, there are ₆ C ₃ = 20 combinations for selecting three from the six antennas. When 20 packets addressed to terminal B 603 are transmitted, terminal A 602 can measure each propagation path for all combinations of antenna selections. And terminal A602 memorize | stores the parameter | index of the measured reception performance for every combination of each antenna.

  When the received packet is addressed to the own station, the terminal A 602 performs control so as to select the combination of antennas having the highest performance from the propagation paths measured in advance. If the terminal identification signal can be received before the information signal as in this embodiment, measurement can be performed following a changing propagation path, so that a combination of antennas with good performance can always be selected. High performance reception is possible.

  As an index of reception performance, if a determinant is obtained from the channel matrix of the propagation path and multiplied by the estimated signal-to-noise ratio, this is an index that takes into account both ease of stream separation and the received signal level. Is preferable.

  As a configuration of the receiving terminal, for example, when there are three receiving systems and two redundant antennas are prepared, an optimal combination of three antennas is selected from five antennas, so there are 10 types of receiving terminals. There are combination patterns. Therefore, in the case of identification information addressed to other stations, the antenna combination pattern is changed for each packet, and the reception performance is obtained for each of the 10 combinations. When 10 packets or more are transmitted, it is preferable to average with past values.

  FIG. 10 shows the configuration of the receiving side in the wireless packet communication apparatus of this embodiment. The wireless packet communication apparatus of this embodiment includes an identification information match detection unit 553 that determines whether the identification information included in the packet matches the identification information of the terminal itself, an antenna combination change unit 537 that changes the combination of antennas, and received data Is not addressed to the own terminal, the channel estimation unit 550 that measures the propagation path for each packet, the storage unit 552 that stores the reception performance index for each combination of antennas, and the received data is addressed to the own terminal. And a selection unit 554 that selects a combination of high antennas.

  The wireless packet communication apparatus according to the present embodiment detects a match of identification information, and if there is a match, selects a combination with the best characteristics in the performance indexing of propagation path estimation stored for each combination of antennas. Change the combination. On the other hand, if the identification information does not match, the antenna combination pattern is changed by the selection unit 554, the propagation path is estimated, and the performance for the selected antenna combination pattern is stored in the storage unit 552 after performance indexing. deep.

  In the wireless packet communication device of this embodiment, a unique identification signal indicating that the signal is transmitted from an access point is transmitted at a timing prior to information data based on the standard, and is indicated in the identification signal. When it is determined that the signal is addressed to another terminal based on the identification information, the channel estimation measurement for selecting the optimal antenna combination is performed, and the estimation result and the antenna combination are stored in association with each other. When a signal addressed to the terminal is transmitted, it is possible to select a combination of antennas having the highest reception performance from among the stored correspondences, thereby enabling high-performance transmission with a low packet error rate. .

  According to the present invention, a unique operation mode can be established without losing the interoperability with a terminal compliant with the IEEE 802.11 communication standard, and in particular, the operation mode is unique before starting reception of an information signal. Therefore, it is possible to realize a wireless LAN device capable of high-performance reception such as use of an iterative decoding method capable of improving reception characteristics and selection of an antenna combination pattern. Note that the unique operation mode is not limited to the use of the iterative decoding method and the selection of the antenna combination pattern, but also the use of a unique error correction code.

The figure which shows an example of the block circuit diagram which shows the radio | wireless packet communication apparatus in 1st embodiment of this invention The figure which shows an example of the block circuit diagram which shows the radio | wireless packet communication apparatus in 1st embodiment of this invention Explanatory drawing which shows the subcarrier which is not used for transmission of the information signal in 1st embodiment of this invention The figure which shows an example of the figure which shows the radio | wireless packet in 1st embodiment of this invention The figure which shows an example of the block circuit diagram which shows the radio | wireless packet communication apparatus in 1st embodiment of this invention The figure which shows an example of the block circuit diagram which shows the radio | wireless packet communication apparatus in 1st embodiment of this invention The figure which shows an example of the block circuit diagram which shows the radio | wireless packet communication apparatus in 2nd embodiment of this invention The figure which shows an example of the block circuit diagram which shows the radio | wireless packet communication apparatus in 2nd embodiment of this invention The conceptual diagram which shows the relationship between the access point and multiple terminal in 2nd embodiment of this invention The figure which shows an example of the block circuit diagram which shows the radio | wireless packet communication apparatus in 2nd embodiment of this invention The figure which shows an example of the block circuit diagram which shows the conventional radio | wireless communication apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 MAC data generation part 102 Compatibility determination part 103 MCS determination part 104 Dummy data addition amount determination part 105 Dummy data addition part 106 Encoding part 107 SIG generation part 108 SIG addition part 109 Mapping part 110 IFFT part 111 GI addition part 112 Preamble Generation unit 113 Preamble addition unit 114 Independent operation information generation unit 115 Identification number assignment unit 131, 132, 133 Subcarrier 201 Legacy-STS (Short Training Symbol)
202 Legacy-LTS (Long Training Symbol)
203 Legacy-SIGNAL
204 HT (High Throughput) -SIGNAL1
205 HT-SIGNAL2
206 HT-STS
207 HT-LTS1
208 HT-LTS2
209 Data 301 SIG generation unit 401 MAC data signal generation unit 402 Dummy data addition unit 403 Wireless packet information generation unit 404 First encoding unit 405 Second encoding unit 406 Wireless packet generation unit 407 Wireless transmission processing unit 502 Analog unit 503 Baseband processing unit 504 MAC processing unit 505 Upper layer processing unit 515 Reception processing unit 516 Reception signal analysis unit 517 Transmission processing unit 521, 547 Synchronization unit 522, 548 Demodulation unit 523, 550 Channel estimation unit 524, 527, 549 Determination unit 525 Decoding Method Determining Unit 526 Canceling Unit 528 Switching Unit 537 Antenna Combination Changing Unit 551 Performance Indexing Unit 552 Storage Unit 553 Identification Information Match Detection Unit 554 Selection Unit

Claims (18)

A wireless packet communication apparatus, wherein a wireless packet signal is configured to include information data and transmission information describing a modulation method and a wireless transmission time of the information data, and the transmission information is transmitted before the information data. ,
Means for adding predetermined data to the information data;
Means for performing a change process of information relating to the wireless transmission time according to the amount of the predetermined data added;
A wireless packet communication apparatus including means for transmitting the content of the change process before transmitting the information data. The wireless packet communication device according to claim 1,
A wireless packet communication apparatus, wherein the means for transmitting the content of the change process transmits the content of the change process using a subcarrier that is not used for transmission of information data. The wireless packet communication device according to claim 2,
The wireless packet communication apparatus, wherein the means for transmitting the content of the change process transmits the content of the change process using a plurality of subcarriers that are not used for transmission of information data. The wireless packet communication device according to claim 1,
A wireless packet communication apparatus, wherein the means for transmitting the contents of the change process transmits differentially encoded subcarriers not used for transmission of information data. The wireless packet communication device according to claim 1,
Including means for confirming compatibility with the receiving terminal,
The wireless packet communication apparatus, wherein the means for adding the predetermined data adds the predetermined data to the information data only when there is compatibility. The wireless packet communication device according to claim 5,
A means for confirming the compatibility, a function of transmitting a predetermined sequence using a plurality of subcarriers not used for transmission of information data;
A function for recognizing that a predetermined sequence is transmitted on the receiving side;
A wireless packet communication apparatus including a function of returning a predetermined sequence using a plurality of subcarriers not used for transmission of information data. A wireless packet communication apparatus, wherein a wireless packet signal is configured to include information data and transmission information describing a modulation method and a wireless transmission time of the information data, and the transmission information is transmitted before the information data. ,
The wireless transmission time is described in the first transmission information and the second transmission information,
Means for adding predetermined data to the information data;
Means for changing information related to the wireless transmission time described in the first transmission information according to the added predetermined data amount;
Means for changing information relating to the wireless transmission time described in the second transmission information according to the added predetermined data amount,
The wireless packet communication device, wherein the information related to the wireless transmission time described in the first transmission information represents a time longer than the time required for actual wireless transmission. The wireless packet communication device according to claim 7,
The wireless packet communication apparatus, wherein the information regarding the wireless transmission time described in the second transmission information is set according to ½ of the added predetermined data amount. The wireless packet communication device according to claim 1,
A MAC data signal generator for converting a signal from an upper layer into a MAC signal;
According to the result of the received signal analysis, a compatibility determination unit that determines whether the receiver is compatible,
An MCS determination unit that determines a modulation scheme, a coding rate, and a data length according to a result of received signal analysis;
Dummy data addition amount determination that determines the amount of dummy data to be added according to the modulation scheme, coding rate, and data length determined by the MCS determination unit when the compatibility determination unit determines that there is compatibility And
A dummy data adding unit for adding the amount of dummy data determined by the dummy data addition amount determining unit to the MAC signal;
An encoding unit for encoding the MAC signal to which the dummy data is added;
A unique operation information generation unit that generates unique form of operation information that is information indicating that the dummy data has been added;
A SIG generation unit that generates a SIGNAL signal according to the modulation scheme, coding rate, and data length determined by the MCS determination unit;
A SIG adding unit that adds the SIGNAL signal generated by the SIG generating unit before the encoded MAC signal;
A radio packet communication apparatus comprising: a mapping unit that maps both the output signal of the SIG adding unit and the operation information in the unique form according to a predetermined modulation scheme. The wireless packet communication device according to claim 1,
A MAC data signal generator for converting a signal from an upper layer into a MAC signal;
According to the result of the received signal analysis, a compatibility determination unit that determines whether the receiver is compatible,
An MCS determination unit that determines a modulation scheme, a coding rate, and a data length according to a result of received signal analysis;
Dummy data addition amount determination that determines the amount of dummy data to be added according to the modulation scheme, coding rate, and data length determined by the MCS determination unit when the compatibility determination unit determines that there is compatibility And
A dummy data adding unit for adding the amount of dummy data determined by the dummy data addition amount determining unit to the MAC signal;
An encoding unit for encoding the MAC signal to which the dummy data is added;
The SIGNAL signal is generated according to the modulation scheme, coding rate, and data length determined by the MCS determination unit, and the Length indicating the packet length described in the Legacy-SIGNAL signal and the HT-SIGNAL signal included in the transmission information A SIG generator for changing the value;
A radio packet communication apparatus, comprising: a SIG adding unit that adds a SIGNAL signal generated by the SIG generating unit before an encoded MAC signal. A radio packet signal is composed of information data, transmission information describing the modulation method of the information data and radio transmission time, a known preamble signal for estimating a propagation path, etc., and the preamble signal is preceded by the information data A wireless packet communication device to be transmitted,
Means for grasping the terminal to be communicated;
Means for confirming whether or not the grasped terminal is a specification allowing a unique operation mode;
A means of giving identification information to each terminal when the specification allows a unique operation mode;
Means for transmitting the identification information before the information data. The wireless packet communication device according to claim 11,
A wireless packet communication apparatus, wherein the means for transmitting the identification information transmits the identification information using a subcarrier that is not used for transmission of information data. The wireless packet communication device according to claim 11,
A wireless packet communication apparatus, wherein the means for transmitting the identification information transmits the identification information using a plurality of subcarriers that are not used for transmission of information data. The wireless packet communication device according to claim 11,
A wireless packet communication apparatus, wherein the means for transmitting the identification information transmits sub-carriers that are not used for transmission of information data by differential encoding. The wireless packet communication device according to claim 11,
Including means for confirming compatibility with the receiving terminal,
The means for confirming the compatibility is:
A function of transmitting a predetermined sequence using a plurality of subcarriers not used for transmission of information data;
A function for recognizing that a predetermined sequence is transmitted on the receiving side;
A wireless packet communication apparatus including a function of returning a predetermined sequence using a plurality of subcarriers not used for transmission of information data. The wireless packet signal is configured to include information data and transmission information describing a modulation method and a wireless transmission time of the information data, and the transmission information is a wireless packet communication device that is transmitted before the information data,
The wireless transmission time is described in the first transmission information and the second transmission information, and means for changing information relating to the wireless transmission time described in the first transmission information according to the assigned identification information A wireless packet communication device. The wireless packet communication device according to claim 11,
A MAC data signal generator for converting a signal from an upper layer into a MAC signal;
According to the result of the received signal analysis, a compatibility determination unit that determines whether the receiver is compatible,
An identification number assigning unit that assigns an identification number that identifies the receiving side when it is determined to be compatible with the receiving side;
An MCS determination unit that determines a modulation scheme, a coding rate, and a data length according to a result of received signal analysis;
An encoding unit for encoding the MAC signal;
A SIG generation unit that generates a SIGNAL signal according to the modulation scheme, coding rate, and data length determined by the MCS determination unit;
A SIG adding unit that adds the SIGNAL signal generated by the SIG generating unit before the encoded MAC signal;
A radio packet communication apparatus comprising: a mapping unit that maps both the output signal of the SIG adding unit and the identification number according to a predetermined modulation scheme. The wireless packet communication device according to claim 11,
A MAC data signal generator for converting a signal from an upper layer into a MAC signal;
According to the result of the received signal analysis, a compatibility determination unit that determines whether the receiver is compatible,
An identification number assigning unit that assigns an identification number that identifies the receiving side when it is determined to be compatible with the receiving side;
An MCS determination unit that determines a modulation scheme, a coding rate, and a data length according to a result of received signal analysis;
An encoding unit for encoding the MAC signal;
The SIGNAL signal is generated according to the modulation scheme, coding rate, and data length determined by the MCS determination unit, and the Length indicating the packet length described in the Legacy-SIGNAL signal and the HT-SIGNAL signal included in the transmission information A SIG generator for changing the value;
A radio packet communication apparatus, comprising: a SIG adding unit that adds a SIGNAL signal generated by the SIG generating unit before an encoded MAC signal.

Images