JP2008306599A - Communication apparatus, communication method, communication system, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly switch a beam of a phased array antenna or an antenna of antenna switching diversity, using a simple structure. <P>SOLUTION: A communication apparatus includes a MAC 26 for determining whether a received signal is addressed to the communication apparatus, based on an address included in the received signal, and when the received signal is not addressed to the communication apparatus, transmitting a reset signal, a channel correcting unit 18 for obtaining a channel estimated value of the received signal, a memory 30 for storing channel estimated values, a comparison unit 28b for comparing the channel estimated values stored in the memory 30, a beam number determining unit 28a for determining a beam or an antenna for reception based on the result of comparison of the channel estimated values, and a controller 28 for canceling storage of a channel estimated value into the memory 30 when receiving the reset signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a communication device, a communication method, a communication system, and a program.

  Conventionally, for example, Japanese Patent Application Laid-Open No. 2005-348137 discloses a technique for suppressing power consumption by selecting a good antenna in a diversity receiver. Japanese Patent Laid-Open No. 2005-354346 discloses a technique for switching a signal generated by a MIMO transmission unit according to the state of a transmission path. Japanese Patent Laid-Open No. 2006-94394 describes a technique for switching a wireless channel according to a communication situation.

JP 2005-348137 A JP 2005-354346 A JP 2006-94394 A

In the case of a conventional phased array antenna, the data link layer (MAC) controls the reception status determination and the like. For example, in the case of the CSMA method, the MAC uses the result of decoding the MAC header of the received packet signal to determine whether or not the information is transmitted to the own device. In such a system, when it is determined by the MAC that the signal is addressed to the own device, the channel information transmitted from the physical layer is used.
MAC controls the beam switching.

  However, in the method of switching the plurality of antennas such as the phased array antenna beam or the antenna switching diversity by determining the reception status led by the MAC, there are many information exchanges between the physical layer and the MAC layer. There is a problem that the control becomes complicated. Also, when the interface between the physical layer and the MAC layer is low speed, it is difficult to exchange sufficient information between the physical layer and the MAC layer, especially when packets are transmitted continuously. If the packet interval is short, it is assumed that the beam or antenna cannot be switched between packets. For this reason, it is difficult to perform adaptive beam control and antenna control, and there is a possibility that reception characteristics may be deteriorated.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is a new and improved technique capable of switching between a beam and an antenna in a short time with a simple configuration. A communication apparatus, a communication method, a communication system, and a program are provided.

  In order to solve the above problem, according to an aspect of the present invention, it is determined whether or not a received signal is addressed to the own apparatus based on an address included in the received signal, and the received signal is not addressed to the own apparatus. A reset signal transmission unit that transmits a reset signal, a channel estimation value acquisition unit that acquires a channel estimation value of a received signal, a channel estimation value storage unit that stores the channel estimation value, and a channel estimation value storage unit A channel estimation value comparison unit that compares the channel estimation values, a selection unit that selects a beam or antenna for reception based on the comparison result of the channel estimation values, and the reset signal, A control unit that stops storing the channel estimation value in the channel estimation value storage unit.

  According to the above configuration, it is determined whether or not the received signal is addressed to the own device based on the address included in the received signal. If the received signal is not addressed to the own device, the reset signal is transmitted from the reset signal transmitting unit. . Further, the channel estimation value of the received signal is acquired and stored, and the stored channel estimation value is compared. Based on the comparison result of the channel estimation values, a beam or antenna for reception is selected. At this time, when a reset signal is received, the storage of the channel estimation value is stopped. Accordingly, it becomes possible to select a beam or an antenna based only on the channel estimation signal addressed to the own apparatus.

  The reset signal transmission unit may be included in a data link layer, and the channel estimation value acquisition unit, the channel estimation value storage unit, the selection unit, and the control unit may be included in a physical layer. According to such a configuration, the process of selecting a beam or antenna based on the channel estimation value can be performed in the physical layer, and the amount of information transmitted and received between the physical layer and the data link layer is minimized. Therefore, it is possible to simplify the processing relating to the selection of the beam or antenna, and to select the beam or antenna in a short time.

  In addition, a decoding processing unit is further provided that performs a decoding process on the received signal and transmits a reception end signal to the control unit when the decoding process of the received signal is completed. When the reset signal is received before reception, the channel estimation value may be stored mainly in the channel estimation value storage unit. According to such a configuration, when the reset signal is received before the reception end signal is received, it can be determined that the received signal is not addressed to the own device. A beam or antenna can be selected based only on the channel estimation signal addressed to the destination.

  In addition, after selecting the beam or antenna, further comprising a fixed period counting unit that counts the fixed period of the beam or antenna every time a packet signal is received, the selection unit selects the beam or antenna, The state of the selected beam or antenna may be maintained until the fixed period reaches a predetermined value. According to such a configuration, since the state of the selected beam or antenna is maintained until the fixed period reaches a predetermined value, it continues with the beam or antenna that is determined to have good reception based on the channel estimation value. Can be received.

  A channel estimation value counting unit configured to count the channel estimation value stored in the channel estimation value storage unit, wherein the channel estimation value comparison unit has a count number of the channel estimation value of the beam or the antenna; When the number is reached, the channel estimation values may be compared. According to this configuration, since the channel estimation values are compared when the number of channel estimation values reaches the number of beams or antennas, channel estimation values corresponding to all beams or antennas can be compared. And a beam or an antenna with the best reception condition can be selected.

  Further, a beacon transmission / reception determination unit that determines whether or not beacon transmission / reception is performed, and when beacon transmission / reception is not performed, acquisition of the channel estimation value, storage of the channel estimation value, and the channel Comparison of estimated values and selection of the beam or antenna may be performed. According to such a configuration, it is possible to acquire a channel estimation value, store a channel estimation value, compare channel estimation values, and select a beam or an antenna only when no beacon transmission / reception is performed.

  In order to solve the above problem, according to another aspect of the present invention, based on an address included in a received signal, it is determined whether the received signal is addressed to the own device, and the received signal is addressed to the own device. If not, transmitting a reset signal; obtaining a channel estimate of the received signal; storing the channel estimate in a memory; comparing the channel estimate stored in the memory; Selecting a beam or an antenna for reception based on the comparison result of the channel estimation values, and storing the channel estimation value in the channel estimation value storage unit when the reset signal is received. And providing a communication method.

  According to the above configuration, it is determined whether or not the received signal is addressed to the own apparatus based on the address included in the received signal. If the received signal is not addressed to the own apparatus, a reset signal is transmitted. Further, the channel estimation value of the received signal is acquired and stored, the stored channel estimation values are compared, and a beam or antenna for reception is selected based on the comparison result of the channel estimation values. Then, when the reset signal is received, the storage of the channel estimation value is stopped. Accordingly, it becomes possible to select a beam or an antenna based only on the channel estimation signal addressed to the own apparatus.

  In addition, the method further includes a step of performing a decoding process on the received signal and transmitting a reception end signal to the control unit when the reception signal decoding process is completed, and in the step of stopping storing the channel estimation value, When the reset signal is received before the reception end signal is received, the storage of the channel estimation value in the channel estimation value storage unit may be stopped. According to such a configuration, when the reset signal is received before the reception end signal is received, it can be determined that the received signal is not addressed to the own device. A beam or antenna can be selected based only on the channel estimation signal addressed to the destination.

  In addition, after selecting the beam or antenna, the method further includes a step of counting a fixed period of the beam or antenna every time a packet signal is received. In the step of selecting the beam or antenna, the beam or antenna is After the selection, the state of the selected beam or antenna may be maintained until the fixed period reaches a predetermined value. According to such a configuration, since the state of the selected beam or antenna is maintained until the fixed period reaches a predetermined value, it continues with the beam or antenna that is determined to have good reception based on the channel estimation value. Can be received.

  In addition, the method further includes the step of counting the channel estimation values stored in the channel estimation value storage unit, and in the step of comparing the channel estimation values, the count number of the channel estimation values is equal to the number of the beams or the antennas. The channel estimation values may be compared when they are reached. According to this configuration, since the channel estimation values are compared when the number of channel estimation values reaches the number of beams or antennas, channel estimation values corresponding to all beams or antennas can be compared. And a beam or an antenna with the best reception condition can be selected.

  Further, the method further includes a step of determining whether or not beacon transmission / reception is performed, and when beacon transmission / reception is not performed, acquisition of the channel estimation value, storage of the channel estimation value, and Comparison and selection of the beam or antenna may be performed. According to such a configuration, it is possible to acquire a channel estimation value, store a channel estimation value, compare channel estimation values, and select a beam or an antenna only when no beacon transmission / reception is performed.

  In order to solve the above problem, according to another aspect of the present invention, a communication system in which a transmission device and a reception device are connected via a wireless communication network, wherein the reception device is the transmission device. Based on the address included in the received signal received from the receiver, determines whether the received signal is addressed to the own device, and if the received signal is not addressed to the own device, a reset signal transmitting unit that transmits a reset signal, A channel estimation value acquisition unit that acquires a channel estimation value, a channel estimation value storage unit that stores the channel estimation value, a channel estimation value comparison unit that compares the channel estimation value stored in the channel estimation value storage unit, A selection unit that selects a beam or an antenna for reception based on the comparison result of the channel estimation value, and the channel when the reset signal is received. A control unit for stopping the saving to the channel estimation value storage unit Le estimates, the communication system comprising a provided.

  According to the above configuration, it is determined whether or not the received signal is addressed to the own device based on the address included in the received signal received from the transmitting device. If the received signal is not addressed to the own device, the reset signal is transmitted from the reset signal transmitting unit. A signal is transmitted. Further, the channel estimation value of the received signal is acquired and stored, and the stored channel estimation value is compared. Based on the comparison result of the channel estimation values, a beam or antenna for reception is selected. At this time, when a reset signal is received, the storage of the channel estimation value is stopped. Accordingly, it becomes possible to select a beam or an antenna based only on the channel estimation signal addressed to the own apparatus.

  In order to solve the above problem, according to another aspect of the present invention, a means for receiving a reset signal transmitted from the data link layer when the received signal is not addressed to the own device, a channel estimation value of the received signal is obtained. Means for acquiring, means for storing the channel estimation value, means for comparing the channel estimation values stored in the channel estimation value storage unit, and selecting a beam or an antenna based on the comparison result of the channel estimation values And a program for causing a computer to function as means for canceling storage of the channel estimation value in the channel estimation value storage unit when the reset signal is received.

  According to the above configuration, it is determined whether or not the received signal is addressed to the own device based on the address included in the received signal. If the received signal is not addressed to the own device, the reset signal is transmitted from the reset signal transmitting unit. . Further, the channel estimation value of the received signal is acquired and stored, and the stored channel estimation value is compared. Based on the comparison result of the channel estimation values, a beam or antenna for reception is selected. At this time, when a reset signal is received, the storage of the channel estimation value is stopped. Accordingly, it becomes possible to select a beam or an antenna based only on the channel estimation signal addressed to the own apparatus.

  According to the present invention, it is possible to provide a communication device, a communication method, a communication system, and a program capable of switching beams and antennas in a short time with a simple configuration.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  FIG. 1 is a schematic diagram showing a configuration of a communication apparatus 100 according to an embodiment of the present invention. The communication apparatus 100 according to the present embodiment is applied to a system having a channel estimation sequence such as a wireless LAN, a wireless PAN, and the like. In particular, the communication apparatus 100 determines whether the signal is addressed to the own apparatus based on the information of the MAC header of the packet signal. It can be applied to the CSMA method for determination.

  As illustrated in FIG. 1, the communication apparatus 100 includes a phased array antenna 10, an RF circuit 12, an AD conversion unit 14, an FFT 16, a channel correction unit (Channel Compensation) 18, a deinterleaver (Deinterleaver) 20, and a depuncture (Depuncture) 22. A decoder 24, a MAC 26, a controller 28, and a memory 30. The phased array antenna 10 includes three antennas 10a, 10b, and 10c, and three beams 1 to 3 can be used.

  In FIG. 1, high-frequency signals received by the antennas 10 a, 10 b, and 10 c are amplified by the RF circuit 12 and converted into digital signals by the AD conversion unit 14. The received signal converted into the digital signal is fast Fourier transformed by the FFT 16 and sent to the channel correction unit 18.

  The channel correction unit 18 performs processing for correcting the channel based on the channel estimation signal (CE) included in the received signal. The signal corrected by the channel correction unit 18 is sent to the deinterleaver 20. The deinterleaver 20 performs a process for returning the interleaved received signal. The reception signal output from the deinterleaver 20 is sent to the decoder 22 for decoding. The output from the decoder 22 is sent to a MAC (data link layer) 26.

  In FIG. 1, an RF circuit 12, an AD conversion unit 14, an FFT 16, a channel correction unit (Channel Compensation) 18, a deinterleaver 20, a depuncture 22, a decoder 24, a controller 28, The memory 30 constitutes a physical layer (PHY) 50.

  FIG. 2 is a schematic diagram illustrating an example of a data configuration of a packet signal. As shown in FIG. 2, the packet signal includes a preamble, a channel estimation signal (CE), a header, and a payload. Of these, the header is divided into a PHY header and a MAC header. The PHY header includes information such as the transmission rate of the payload and the length of the payload. On the other hand, the MAC header includes a MAC address indicating the destination of the packet signal. By reading the MAC address, the MAC 26 can identify whether the received packet signal has been transmitted to the own device or to another device.

  FIG. 3 is a schematic diagram schematically showing information exchange between the physical layer 50 and the MAC 26. In the physical layer 50, when the beams 1 to 3 are switched by the phased array antenna 10, channel estimation values (RSSI, LQI) are calculated for the beams 1 to 3, respectively. Here, RSSI is information indicating the power of the received signal, and LQI is information indicating the status of the channel of the received signal. The calculation of the channel estimation value is performed by the controller 28 based on the channel estimation signal (CE) acquired by the channel correction unit 18.

  The channel estimation value calculated by the physical layer 50 is stored in the memory 30 of the physical layer 50. The controller compares the channel estimation values corresponding to the antennas 10a, 10b, and 10c, and switches the beams 1 to 3 using the antenna having the good reception status among the three antennas 10a, 10b, and 10c. Do.

  When the physical layer 50 of the communication apparatus 100 receives the packet signal, the decoder 24 decodes the packet signal. When the decoding of the packet signal (payload decoding) is completed, a reception end signal is sent from the decoder 24 to the controller 28.

  On the other hand, the signal received by the communication device 100 includes a signal that is not transmitted to the communication device 100. For this reason, when the communication device 100 receives the packet signal, the MAC 26 determines whether the received signal is addressed to the own device based on the information of the MAC header of the packet. If the received packet signal is not addressed to the own device, a reset signal is transmitted from the MAC 26 to the physical layer 50. When receiving the reset signal from the MAC 26, the controller 28 of the physical layer 50 stops the decoding of the payload by the decoder 24. As a result, if the packet signal is not addressed to its own device, reception can be terminated before all packet signals are received, unnecessary decoding processing can be avoided, and power consumption can be reduced. .

  At this time, as described above, the channel estimation value obtained by packet reception is stored in the memory 30. However, if the packet signal is not addressed to the own apparatus, it is not necessary to store the channel estimation value in the memory 30.

  In this embodiment, paying attention to the fact that it is possible to determine whether or not the received packet signal is addressed to the own device when the reset signal is sent from the MAC 26 to the physical layer 50, the reset signal is sent from the MAC 26 to the physical layer 50. If received, since the received packet signal is not addressed to the own apparatus, processing is performed so that the channel estimation value calculated from the packet signal is not stored in the memory. More specifically, a reset signal is sent from the MAC 26 to the physical layer 50 when the reception is completed even when the received packet signal is addressed to its own device. If a reset signal is sent from the MAC 26 to the physical layer 50 before being sent, it is determined that the received packet signal is not addressed to its own device, and processing is performed so that the channel estimation value is not stored in the memory.

  Thus, since it is possible to determine whether or not to save the channel estimation value in the memory 30 using the reset signal transmitted from the MAC 26 to the physical layer 50, the amount of information transmitted and received between the physical layer 50 and the MAC 26 is minimized. To the limit. Further, since the channel estimation value is stored in the memory 30 of the physical layer 50, it is not necessary to transmit the channel estimation value to the MAC 26, and the processing speed can be increased.

  FIG. 4 shows a functional block configuration of the controller 28 of the physical layer 50 for performing the above-described processing. As shown in FIG. 4, the controller 28 includes a beam number determining unit 28a, a comparing unit 28b, a data reading unit 28c, and a data receiving / saving unit 28d.

  The data reception / storage unit 28 d stores the channel estimation value in the memory 30 based on the reset signal received from the MAC 26. At this time, if the reset signal is not received from the MAC 26, the channel estimation value is stored in the memory 30. If the reset signal is received from the MAC 26, processing is performed so that the channel estimation value is not stored in the memory 30.

  The data reading unit 28 c performs processing for reading the channel estimation values of each beam from the memory 30 after the channel estimation values of the beams 1 to 3 are stored in the memory 30. The comparison unit 28b compares the channel estimation values read from the memory 30, and the beam number determination unit 28a determines the beam number with the best reception status based on the comparison result by the comparison unit 28b. Transmit to the RF circuit 12. As a result, the received beam is switched in the RF circuit 12.

  As described above, in the system of the present embodiment, the processing for switching the beams 1 to 3 is basically performed in the physical layer 50 and can be performed only by receiving the reset signal from the MAC 26. Therefore, the amount of information transmitted and received between the physical layer 50 and the MAC 26 can be minimized, and the control can be greatly simplified.

  In particular, in a system that sends a channel estimation signal from the physical layer to the MAC, determines the beam with the best reception status on the MAC side, and sends the determination result to the physical layer, the amount of information transmitted and received between the physical layer and the MAC Increases the time required for beam selection and switching. When packets are transmitted continuously, beam switching is performed between packets. Therefore, if the time for beam selection and switching becomes long, the interval between packets cannot be shortened.

  According to the system of this embodiment, storage of channel estimation signals, comparison of channel estimation values, and beam switching are all performed on the physical layer 50 side. Therefore, it is not necessary to send a channel estimation value from the physical layer 50 to the MAC 26, and the amount of information transmitted and received between the physical layer 50 and the MAC 26 can be minimized, and beam selection and beam switching are performed in the physical layer 50. Can be done instantly on the side. Therefore, it is possible to greatly shorten the interval between successive packets, and as a result, it is possible to increase the data density and to greatly improve the transmission efficiency. Therefore, according to the present embodiment, for example, even in standards such as MIFS and RIFS in which the time interval between packets is extremely shortened, it is possible to instantaneously switch the beam between packets.

  FIG. 5 is a timing chart showing processing in the communication apparatus 100 of the present embodiment. FIG. 5 shows a case where packet signals A to K are continuously received. The reception end signal is transmitted from the decoder 24 to the controller 28 when reception of each of the packets A to K is completed. The reception end signal is transmitted both when the packet signal is addressed to the own device and all of the packet signals are decoded, or when the packet signal is not addressed to the own device and decoding is stopped halfway. As described above, the reception reset signal is transmitted from the MAC 26 to the controller 28 when it is determined from the MAC address that the packet signal is not addressed to the own device.

  In FIG. 5, with packet signals A, B, D, E, G, H, I, J, and K, reception of the packet reset signal is issued after reception of the packet signal is completed and a reception end signal is issued. Yes. Therefore, when receiving the packet signals A, B, D, E, G, H, I, J, K, the reception reset signal is not issued during decoding, and the packet signals A, B, D, E , G, H, I, J, K are signals addressed to the own device.

  On the other hand, when the packet signals C and F are received, the reception reset signal is issued before the end of the packet signals C and F, and the reception reset signal is received at a timing before all the decoding of the packet signals is completed. Has been issued. This is because the MAC 26 determines that the packet signals C and F are not signals addressed to the own apparatus, and a reception reset signal is issued before decoding is completed.

  In FIG. 5, the number M of beams indicates the number of beams whose channel estimation values are stored in the memory 30. Here, as shown in FIG. 1, a case where the total number of beams is three is shown. The fixed period N indicates a period in which a beam having the best reception status is determined and then fixed to the beam. The value of the fixed period N is increased by 1 every time one packet is received after the beam is fixed, and when the value of the fixed period N becomes 4, the process shifts to the beam switching process again. Moreover, in FIG. 4, the beam number has shown the number of the beam currently selected among the beams 1-3.

  In FIG. 5, at the time t0, the channel estimation value stored in the memory 30 is reset, and the value of the stored beam number M is zero. Between time t0 and time t1, the three beams are sequentially switched and a process of storing the channel estimation value of each beam in the memory 30 is performed.

  As shown in FIG. 5, while the packet signal A is being received, the beam 1 (beam number 1) is being received. The channel estimation value at the time of receiving with the beam 1 is stored in the memory 30. After the packet signal A is received, the value of the number of beams M is 1.

  After receiving the packet signal A, switching to the beam 2 is performed, and the packet signal B is received. The channel estimation value when the beam 2 is received is stored in the memory 30. After the packet signal B is received, the beam number M is 2.

  After receiving the packet signal B, switching to the beam 3 is performed and the packet signal C is received. However, since the reception reset signal is output from the MAC 26 while the packet signal C is being decoded, the beam 3 Is not stored in the memory 30. Therefore, even when the packet signal D is received after the reception of the packet signal C, the number of beams M representing the number of channel estimation values stored in the memory 30 remains two. In addition, since the channel estimation value at the time of receiving the beam 3 is not stored in the memory 30, the packet signal D is continuously received by the beam 3 after receiving the packet signal C. Then, after the reception of the packet signal D is completed, the channel estimation value when it is received by the beam 3 is stored in the memory 30, and the value of the number of beams M is 3.

  At the time when the reception of the packet signal D is completed, the number M of beams stored in the memory 30 is 3, and in the memory 30, the channel estimation value when received by the beam 1 and the channel when received by the beam 2 are stored. The estimated value and the channel estimated value when received by the beam 3 are stored. After the reception of the packet signal D is completed, these channel estimation values are compared, the beam number having the best reception state is selected, and the beam is selected. In the example of FIG. 5, as a result of comparing the channel estimation values, it is determined that the reception status of the beam 2 is the best, so that the subsequent reception is fixed to the beam 2 and when the packet signal E and subsequent are received, Reception is performed by the beam 2. When the beam is fixed, the channel estimation value stored in the memory 30 is deleted, and the value of the beam number M is reset to zero.

  After being fixed to the beam 2, the value of the fixed period N increases by 1 every time a packet addressed to the own apparatus is received. As shown in FIG. 5, after time t1, the value of the fixed period increases by 1 each time reception of the packet signals E, G, H, and I is completed. Since the packet signal F is not a signal addressed to the own apparatus, the value of the fixed period does not increase when the packet signal F is received. When the value of N reaches 4, the channel estimation value of each beam is acquired and stored again, and switching to the beam with the best reception status is performed. The value of the fixed period N is set to 0 while the channel estimation value of each beam is acquired (between time t0 and time t1).

  At the time t2 when the reception of the packet signal I is completed, the value of the fixed period N is 4. Therefore, after the time t2, the beam is switched every time a packet signal addressed to the own apparatus is received, and channel estimation is performed. The value is calculated, and when the value of the number of beams M becomes 3, the channel estimation values are compared, and the beam is switched again. In the example of FIG. 5, beam switching is performed when the value of the fixed period N reaches 4, but the value of the fixed period N that triggers beam switching depends on the characteristics of the communication apparatus 100. For example, in the case of the mobile communication device 100 in which the reception state is likely to change, it is desirable to reduce the value of the fixed period N for switching the beam.

  Next, based on the flowchart of FIG. 6, the procedure of the process in the communication apparatus 100 of this embodiment is demonstrated. The processing in FIG. 6 is mainly performed by the controller 28. A program for causing the controller 28 to realize the processing in FIG. 6 can be stored in, for example, a storage unit provided in the controller 28, the memory 30, or the like.

  First, in step S1, reception of a packet signal is started. In the next step S2, channel estimation is performed using a channel estimation signal (CE). In the next step S3, the decoder 24 decodes the payload of the packet signal.

  In the next step S4, it is determined whether or not a reception reset signal is generated before reception of the packet signal is completed. Here, it is determined whether or not a reception reset signal has been received from the MAC 26 before receiving a reception end signal from the decoder 24.

  If the reception reset signal has not been generated before the reception of the packet signal is completed in step S4, it is determined that the received packet signal is a signal addressed to the own apparatus because no reception reset signal has been generated during decoding. it can. Therefore, in this case, the process proceeds to step S5, and it is determined whether or not the beam select flag is raised. Here, the beam select flag is in a rising state when any of the beams 1 to 3 is selected and fixed, and in a falling state when the beam is not fixed. In the example of FIG. 5, the beam select flag is in the falling state from time t0 to t1, and is fixed to the beam 2 from time t1 to time t2, so the beam select flag is in the rising state. On the other hand, if the reception reset signal is generated before the reception of the packet signal is completed in step S4, the packet signal is not addressed to the own apparatus, and thus the process is temporarily ended (RETURN).

  If the beam select flag is not raised in step S5, the beam is not fixed, so the process proceeds to step S6 and subsequent steps, and a process for acquiring the channel estimation value of each beam is performed. First, in step S6, the channel estimation value based on the currently selected beam is stored in the memory. In the next step S7, 1 is added to the value of the number of beams M stored in the memory 30 (M = M + 1).

  In the next step S8, it is determined whether or not the number of beams M matches the total number of beams (= 3). If the number of beams M coincides with the total number of beams, calculation of channel estimation values for all beams has been completed, and thus the process proceeds to step S9, and the stored channel estimation values of the beams 1 to 3 are compared. On the other hand, if the number of beams M does not match the total number of beams, the number of beams M has not reached the total number of beams, so the process proceeds to step S15 to perform a process of switching to the next beam. After step S15, the process is temporarily ended (RETURN).

  In the next step S10, the beam of the channel estimation value with the best reception condition is selected based on the comparison result in step S9. The selected beam number is sent to the RF circuit 12. In the next step S11, the beam select flag is raised, and the value of the number of beams M stored in the memory 30 is reset to zero. After step S11, the process is temporarily ended (RETURN).

  If the beam select flag has been raised in step S5, the beam having the best reception status has already been selected. Therefore, the process proceeds to step S12 and subsequent steps, the fixed period N is counted, and the beam select flag is lowered. Process.

  First, in step S12, 1 is added to the current value of N (N = N + 1). In the next step S13, it is determined whether or not the value of N matches the set fixed period value (= 4). If the value of N matches the set fixed period value, step S14 is performed. The process proceeds to, and the beam select flag is lowered. Further, the channel estimation value stored in the memory 30 is reset, and the value of N is reset to 0. After step S14, the process is temporarily ended (RETURN).

  In the above description, the beam switching of the phased array antenna has been described. However, it is also possible to switch the array antenna by the same method. FIG. 7 shows an example applied to a communication apparatus 200 of antenna switching diversity provided with two array antennas 40a and 40b. The communication apparatus 100 in FIG. 7 includes two antennas 40a and 40b and an antenna switching unit 42 that selects one of the antennas 40a and 40b according to the reception status of each antenna 40a and 40b. The other structure of FIG. 7 is the same as that of FIG.

  In the communication apparatus 200 of FIG. 7, when one of the two antennas 40 a and 40 b is selected by the antenna switching unit 42 and one of the antennas 40 a and 40 b is selected, the channel estimation value is stored in the memory 30. Then, similarly to the communication device 100 of FIG. 1, channel estimation values at the time of reception by one of the antennas 40a and 40b are respectively obtained, and an antenna having a good reception state is selected. At this time, similarly to the communication device 100 of FIG. 1, when the reception reset signal is issued before the reception end signal, it is determined that the packet signal is not addressed to the own device, and the channel estimation value to the memory 30 is determined. Control so as not to save.

  FIG. 8 is a schematic diagram showing a configuration of a communication apparatus 300 that controls beam switching according to a beacon transmission / reception period. The basic configuration of the communication apparatus 300 shown in FIG. 8 is the same as that of the communication apparatus 100 of FIG. In addition to the function of the communication device 100 of FIG. 1, the communication device 300 of FIG. 8 does not perform channel estimation value acquisition, storage, and comparison processing, and beam switching processing during the beacon transmission / reception period. It is.

  As shown in FIG. 8, the MAC 26 determines whether or not beacon transmission / reception is performed. When the beacon transmission / reception is performed, a signal indicating a beacon transmission / reception period (beacon transmission / reception period signal) ) To the controller 28 of the physical layer 50.

  While receiving the beacon transmission / reception period signal, the controller 28 controls the communication apparatus 300 so as not to perform the above-described processing relating to beam switching and beam fixation. When the controller 28 has not received the beacon transmission / reception period signal, the operation of the communication device 300 is the same as that of the communication device 100 of FIG.

  For example, when the wireless device A transmits information such as an image to the communication device 300, the communication device 300 directs the beam with the best reception status of the phased array antenna 10 toward the wireless device A. On the other hand, during the beacon transmission / reception period, a control signal is sent from another wireless device B or the like, so it is necessary to receive it. At this time, if the signal from the wireless device B is accumulated as beam switching information, the beam that is suitable for the wireless device A may be shifted, and reception characteristics may deteriorate. According to the present embodiment, while the beacon transmission / reception period signal is received, the beam switching and beam fixing processes described above are not performed, so the beam of the communication apparatus 300 is not switched, and the beam is switched. It becomes possible to face the wireless device A. Thereby, signals such as beacons sent for reception by all devices in the network can be ignored for beam control. Therefore, the beam control is not confused by a control signal such as a beacon, and it is possible to reliably avoid the deterioration of the reception characteristics.

  FIG. 9 is a flowchart showing a processing procedure in the communication apparatus 300 of FIG. In the flowchart of FIG. 9, step S20 for newly determining whether or not it is a beacon transmission / reception period is added between step S3 and step S4 of the flowchart of FIG.

  First, in step S1, reception of a packet signal is started. In the next step S2, the channel estimation unit estimates the channel. In the next step S3, the decoder 24 decodes the payload of the packet signal.

  In the next step S20, based on the beacon transmission / reception period signal transmitted from the MAC 26, it is determined whether or not it is a beacon transmission / reception period. If it is a beacon transmission / reception period, the process is temporarily ended (RETURN). On the other hand, if it is determined in step S20 that it is not a beacon transmission / reception period, the process proceeds to step S4. After step S4, the same processing as in FIG. 6 is performed.

  As described above, according to the present embodiment, based on the reception reset signal transmitted from the MAC 26 to the controller 28 of the physical layer 50, the physical layer 50 side determines whether or not the packet signal is addressed to its own device. be able to. Therefore, it is not necessary to transmit the channel estimation value of each beam from the physical layer 50 to the MAC 26 in order to determine whether or not the packet is addressed to the own apparatus, and the exchange of information between the physical layer 50 and the MAC 26 is minimized. It becomes possible to limit to the limit. Therefore, the beam switching based on the channel estimation value can be instantaneously performed on the physical layer 50 side.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

It is a schematic diagram which shows the structure of the communication apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which shows an example of the data structure of a packet signal. It is a schematic diagram which shows schematically the delivery of the information between a physical layer and MAC. It is a schematic diagram which shows the functional block structure of the controller of a physical layer. It is a timing chart which shows the process in the communication apparatus of one Embodiment of this invention. It is a flowchart which shows the procedure of the process in the communication apparatus of one Embodiment of this invention. It is a schematic diagram which shows the example applied to the communication apparatus of the antenna switching diversity provided with two array antennas. It is a schematic diagram which shows the structure of the communication apparatus which controls switching of a beam according to the transmission / reception period of a beacon. It is a flowchart which shows the procedure of the process in the communication apparatus of FIG.

Explanation of symbols

12 RF circuit 18 Channel correction unit 26 MAC
28 controller 28a beam number determining unit 28b comparing unit 28c data reading unit 28d data receiving / storing unit 30 memory 50 physical layer 100, 200, 300 communication device

Claims (13)

A reset signal transmitting unit that determines whether or not the received signal is addressed to the own device based on an address included in the received signal, and transmits a reset signal when the received signal is not addressed to the own device;
A channel estimation value acquisition unit for acquiring a channel estimation value of the received signal;
A channel estimation value storage unit for storing the channel estimation value;
A channel estimation value comparison unit that compares the channel estimation values stored in the channel estimation value storage unit;
A selection unit that selects a beam or an antenna for reception based on the comparison result of the channel estimation values;
A control unit that, when receiving the reset signal, stops storing the channel estimation value in the channel estimation value storage unit;
A communication apparatus comprising:   The apparatus of claim 1, wherein the reset signal transmission unit is included in a data link layer, and the channel estimation value acquisition unit, the channel estimation value storage unit, the selection unit, and the control unit are included in a physical layer. The communication device described. A decoding processing unit that performs a decoding process on the received signal and transmits a reception end signal to the control unit when the decoding process of the received signal is completed;
The control unit according to claim 1, wherein when the reset signal is received before receiving the reception end signal, the control unit stops storing the channel estimation value in the channel estimation value storage unit. The communication device described.   After the selection of the beam or antenna, it further comprises a fixed period counting unit that counts the fixed period of the beam or antenna every time a packet signal is received, and the selection unit selects the beam or antenna, The communication apparatus according to claim 1, wherein the state of the selected beam or antenna is maintained until the fixed period reaches a predetermined value. A channel estimation value counting unit that counts the channel estimation value stored in the channel estimation value storage unit;
The communication according to claim 1, wherein the channel estimation value comparison unit compares the channel estimation values when the count number of the channel estimation values reaches the number of the beams or the antennas. apparatus. A beacon transmission / reception determination unit that determines whether or not beacon transmission / reception is performed,
The acquisition of the channel estimation value, the storage of the channel estimation value, the comparison of the channel estimation value, and the selection of the beam or antenna are performed when a beacon is not transmitted or received. The communication apparatus as described in. Determining whether the received signal is addressed to the own device based on an address included in the received signal, and transmitting a reset signal when the received signal is not addressed to the own device;
Obtaining a channel estimate of the received signal;
Storing the channel estimate in memory;
Comparing the channel estimates stored in the memory;
Selecting a beam or antenna for reception based on the comparison result of the channel estimates;
Stopping the storage of the channel estimate when the reset signal is received;
A communication method comprising: Further comprising a step of performing a decoding process on the received signal and transmitting a reception end signal to the control unit when the reception signal decoding process is completed,
In the step of canceling the storage of the channel estimation value, the storage of the channel estimation value in the channel estimation value storage unit is stopped when the reset signal is received before the reception end signal is received. The communication method according to claim 7. After selecting the beam or antenna, further comprising the step of counting a fixed period of the beam or antenna each time a packet signal is received,
The state of the selected beam or antenna is maintained in the step of selecting the beam or antenna after the beam or antenna is selected until the fixed period reaches a predetermined value. The communication method described in 1. Counting the channel estimation value stored in the channel estimation value storage unit,
The channel estimation value comparison is performed in the step of comparing the channel estimation values when the count number of the channel estimation values reaches the number of the beams or the antennas. Communication method. Further comprising the step of determining whether a beacon is being transmitted or received,
The acquisition of the channel estimation value, the storage of the channel estimation value, the comparison of the channel estimation value, and the selection of the beam or the antenna are performed when a beacon is not transmitted or received. The communication method described in 1. A communication system in which a transmitting device and a receiving device are connected via a wireless communication network:
The receiving device;
A reset signal transmitting unit that determines whether or not the received signal is addressed to the own device based on an address included in the received signal received from the transmitting device, and transmits a reset signal when the received signal is not addressed to the own device;
A channel estimation value acquisition unit for acquiring a channel estimation value of the received signal;
A channel estimation value storage unit for storing the channel estimation value;
A channel estimation value comparison unit that compares the channel estimation values stored in the channel estimation value storage unit;
A selection unit that selects a beam or an antenna for reception based on the comparison result of the channel estimation values;
A control unit that, when receiving the reset signal, stops storing the channel estimation value in the channel estimation value storage unit;
A communication system comprising: Means for receiving a reset signal transmitted from the data link layer when the received signal is not addressed to the own device;
Means for obtaining a channel estimate of the received signal;
Means for storing the channel estimate;
Means for comparing the channel estimation values stored in the channel estimation value storage unit;
Means for selecting a beam or antenna based on the comparison result of the channel estimates;
Means for canceling storage of the channel estimation value in the channel estimation value storage unit when the reset signal is received;
As a program to make the computer function.

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