JP2011155405A - Radio communication system and base station device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication system and a base station device which suppresses power consumption related to an antenna which is not used. <P>SOLUTION: The radio communication system includes the plurality of base station devices BS for communicating with a ratio terminal device MS by radio and a base station controller C for controlling the plurality of base station devices BS, and at least one of the plurality of base station devices BS includes a plurality of antennas ANT for transmitting and receiving radio signals to/from the radio terminal device MS and a radio part 14 which is provided correspondingly to each of the plurality of antennas ANT and amplifies the radio signals output from the antennas ANT. The radio part 14 clocks the time of not receiving the radio signals from the antennas ANT, and when the clocked time reaches the predetermined time, outputs a reception absence notice indicating that the radio signals are not received for the predetermined time. A control part 15 provided to the base station device BS performs control to stop the function of the radio part at least, when the reception absence notice is output from the radio part. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to power reduction of a base station apparatus of a wireless communication system using, for example, MIMO (Multi Input Multi Output).

  In recent years, the communication speed of wired communication has been increased, and a large amount of data has been transmitted and received. In wireless communication performed by a mobile phone, a PHS (Personal Handy-phone System), etc., there is an increasing demand for transmitting and receiving large volumes of data such as video data and high-quality images. Therefore, in order to increase the communication speed of wireless communication, MIMO (Multi Input Multi Output) technology has attracted attention.

  The MIMO technology is a method of performing communication using a plurality of antennas, and using a plurality of antennas widens the bandwidth by the number of antennas. Theoretically, if the number of antennas is two, the bandwidth is doubled, so that the communication speed can be increased. Such a MIMO technique is applied to both a wireless terminal device such as a mobile phone or PHS that performs wireless communication and a base station device that wirelessly communicates with the wireless terminal device. Among these, since the base station apparatus has a larger transmission power from the antenna than the wireless terminal apparatus, the power consumption of the power amplifier used to transmit the radio wave output from the antenna is also large.

  In addition, even a base station apparatus to which the MIMO technology is applied can perform communication using only one antenna among a plurality of antennas when a necessary communication speed can be processed with one antenna. In this case, since the remaining antennas are on standby even though they are not used, power is continuously supplied to the power amplifiers and peripheral devices corresponding to the unused antennas, which is wasteful from the viewpoint of energy saving. There are many.

  As described above, the base station apparatus consumes a large amount of power by the power amplifier corresponding to each antenna, and even when there is an unused antenna, the base station apparatus is directed to the antenna and its peripheral devices in order to place all antennas on standby. In order to keep supplying electric power, electric power was consumed wastefully.

  For example, Patent Literature 1 is known as a technique related to transmission suppression of useless radio waves in a radio base station apparatus.

JP 2008-109423 A

  In the base station apparatus, the power consumption of the power amplifier corresponding to each antenna is large, and even when there is an antenna that is not used, in order to make all the antennas stand by, to the power amplifier corresponding to the antenna and its peripheral devices There is a problem that power is wasted in order to keep power supplied.

  Therefore, an object of the present invention is to provide a radio communication system and a base station apparatus that can suppress power consumption related to an unused antenna.

  In order to achieve the above object, a wireless communication system according to the present invention includes a plurality of base station apparatuses that wirelessly communicate with wireless terminal apparatuses, and a base station control apparatus that controls the plurality of base station apparatuses. And at least one of the plurality of base station devices is provided corresponding to each of the plurality of antennas that transmit and receive wirelessly with the wireless terminal device, and outputs from the antennas. Amplifies the radio signal, measures the time when the radio signal is not received from the antenna, and outputs a no-reception notification indicating that the radio signal has not been received for the predetermined time when the measured time reaches the predetermined time A radio unit and a control unit that controls to stop at least the function of the radio unit when the notification of no reception is output.

  In order to achieve the above object, a base station apparatus according to the present invention includes a plurality of base station apparatuses that communicate with a radio terminal apparatus by radio and a base station control apparatus that controls the plurality of base station apparatuses. A base station apparatus of a communication system, wherein at least one of the plurality of base station apparatuses is provided corresponding to each of a plurality of antennas that transmit and receive wirelessly with the wireless terminal apparatus, and the plurality of antennas. , Amplifies the radio signal output from the antenna, and measures the time during which the radio signal is not received from the antenna, and indicates that the radio signal has not been received for the predetermined time when the measured time reaches the predetermined time A wireless unit that outputs a notification of no reception, and a control unit that controls to stop at least the function of the wireless unit when the notification of no reception is output. And butterflies.

  According to the radio communication system and the base station apparatus according to the present invention, it is possible to suppress power consumption related to an unused antenna.

1 is a block diagram showing a configuration of a wireless communication system according to an embodiment of the present invention. The block diagram which shows the structure of the base station apparatus which the radio | wireless communications system of FIG. 1 has. The block diagram which shows the structure of the control part with which the base station apparatus of FIG. 2 is equipped. The block diagram which shows the structure of the radio | wireless part with which the base station apparatus of FIG. 2 is equipped. The block diagram which shows the structure of the base station control apparatus which the radio | wireless communications system of FIG. 1 has. The flowchart which shows the process sequence which stops the function of a radio | wireless process part which the base station apparatus which concerns on one embodiment of this invention performs. The flowchart which shows the process sequence which restarts the function of the radio | wireless process part which the radio | wireless base station apparatus based on one embodiment of this invention performs.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a wireless communication system showing an embodiment of the present invention.
The wireless communication system includes base station apparatuses BS1 to BSn (n is a natural number of 1 or more) and base station control apparatuses C1 to C4. The base station apparatuses BS1 to BSn are connected to the base station control apparatus C1 by, for example, an optical cable, and communicate wirelessly with any of the wireless terminal apparatuses MS1 to MS3, and communicate with the base station control apparatus C1 by wire. . Base station control devices C1 to C4 are connected to a mobile communication network and a plurality of base station devices BS. Base station control device C (base station control devices C1 to C4 are collectively referred to as base station control device C) is a wireless terminal device MS (wireless terminal devices MS1 to MS3 are collectively referred to as wireless terminal device MS). ) Is transmitted via the base station apparatus BS (base station apparatuses BS1 to BSn are collectively referred to as base station apparatus BS) and sent to the mobile communication network. Further, the base station control device C sends a signal received from the mobile communication network to the wireless terminal device BS via the base station device BS.

  Although only three wireless terminal devices MS that wirelessly communicate with the base station device BS are illustrated and only four base station control devices C are illustrated, the number of them is not limited thereto.

Next, the configuration of the base station apparatus BS will be described with reference to FIG.
The base station apparatus BS includes a baseband processing unit 11, radio processing units R1 to Rm (m is a natural number of 1 or more), a control unit 15, and antennas ANT1 to ANTm (m is a natural number of 1 or more).
When receiving the downlink signal from the base station controller C, the control unit 15 extracts the payload portion from the data on the IP packet and outputs it to the baseband processing unit 11. In addition, when the payload portion is input from the baseband processing portion 11, the control portion 15 converts the payload portion into an IP packet and sends it to the base station control device C. Further, the control unit 15 monitors the reception state of the wireless unit 14 and determines whether or not a signal is received from the antenna ANT1, and controls the function stop or activation of each unit based on the determination result. Then, the base station controller C is notified of the monitoring results and information regarding the control state of each unit. In addition, the control unit 15 outputs a synchronization clock for synchronization to the baseband processing unit 11 and an OFDM unit 12 and a MODEM unit 13 described later.

  When the payload portion on the IP packet is input from the control unit 15, the baseband processing unit 11 performs baseband processing such as MAC processing and PHY processing, configures a radio frame, and outputs the radio frame to the radio processing unit R <b> 1. Further, when a radio frame is input from the radio processing unit R 1, the baseband processing unit 11 disassembles the radio frame, extracts a payload portion, and outputs the payload portion to the control unit 15.

  The radio processing unit R1 includes an OFDM (Orthogonal Frequency-Division Multiplexing) unit 12, a MODEM (modulation / demodulation) unit 13, and a radio unit 14. The wireless processing unit R1 is formed on a single substrate, for example. The radio frame input from the baseband processing unit 11 to the radio processing unit R1 is processed by the OFDM unit 12. A signal input from the antenna ANT1 to the radio processing unit R1 is processed by the radio unit 14.

When a radio frame is input, the OFDM unit 12 performs OFDM modulation and outputs the result to the MODEM unit 13. Further, the OFDM unit 12 performs OFDM demodulation on the quadrature amplitude demodulated uplink signal output from the MODEM unit 13 and outputs it to the baseband processing unit 11.
The MODEM unit 13 performs quadrature amplitude modulation on the OFDM-modulated signal and outputs the result to the radio unit 14. Also, the MODEM unit 13 receives the uplink signal from the radio unit 14, performs quadrature amplitude demodulation, and outputs it to the OFDM unit 12.
When receiving a signal subjected to quadrature amplitude modulation from the MODEM unit 13, the radio unit 14 amplifies the power and outputs the amplified signal to the antenna ANT1. Further, when the uplink signal is input from the antenna ANT1, the radio unit 14 amplifies the uplink signal with a low noise amplifier and outputs the amplified signal to the MODEM unit 13.

  Since the radio processing units R2 and Rm have the same configuration as the radio processing unit R1, the description of the same configuration is omitted. Note that the antenna ANT2 is connected to the radio processing unit R2, and the antenna ANTm is connected to the radio processing unit Rm. That is, the radio processing unit R and the antenna ANT, which are formed by a single substrate, are connected correspondingly.

Next, the configuration of the control unit 15 provided in the base station apparatus BS will be described with reference to FIG.
The control unit 15 includes a CPU unit 151, a memory 152, a packet generation / decomposition unit 153, a communication interface unit 154, and a clock control unit 155.

  The CPU unit 151 performs various control processes based on a program stored in the memory 152. As one of the control processes, the reception state of the wireless unit 14 is monitored, the presence / absence of signal reception from the antenna ANT1 is determined, and the process of controlling each unit based on the determination result is performed. Setting data necessary for the control process is stored in the memory 152. This control process will be described in detail later.

  The communication interface unit 154 is connected to the base station control apparatus C via an optical cable that performs high-speed optical communication represented by a PON (Passive Optical Network) system, for example. The communication interface unit 154 performs optical / electrical conversion on the optical signal received via the optical cable, and outputs the IP packet received from the base station controller C to the packet generation / decomposition unit 153 and the clock control unit 155. In addition, the communication interface unit 154 sends the IP packet generated by the packet generation / decomposition unit 153 to the base station controller C.

  When an IP packet is input from the communication interface unit 154, the packet generation / decomposition unit 153 determines whether the packet is a control packet for the CPU, a voice packet, or an image packet by referring to the packet header, and decomposes the IP packet. After that, the control packet for the CPU is output to the CPU unit 151, and the voice packet or the image packet is output to the baseband unit. Further, when receiving a radio frame from the baseband processing unit 11, the packet generation / decomposition unit 153 converts the packet into an IP packet and outputs it to the communication interface unit 154.

  The clock control unit 155 extracts the base station synchronization clock from the IP packet input from the communication interface unit 154, regenerates the internal synchronization clock for synchronizing with each unit of the base station apparatus, and distributes it to each unit .

Next, with reference to FIG. 4, the structure of the radio | wireless part 14 with which base station apparatus BS is equipped is demonstrated.
The radio unit 14 includes a reception unit 141, a transmission unit 142, and a BPF (band pass filter) 143.

The BPF 143 is connected to the antenna ANT, outputs a signal received by the antenna ANT to the reception unit 141, and outputs an output signal from the transmission unit 142 to the antenna ANT.
The receiving unit 141 amplifies the signal input from the BPF 143 by a low noise amplifier (not shown) and outputs the amplified signal to the MODEM unit 13. The reception unit 141 includes a timer 141T, and the timer 141T measures the time during which a signal received by the antenna ANT is not input. When the measured time reaches a predetermined time, a no-reception notification indicating that there is no reception for the predetermined time is output to the CPU unit 151 provided in the control unit 15. The CPU 151 stops the function of the wireless processing unit R when receiving the notification of no reception. When the signal to be received from the BPF 143 is received while the function of the wireless processing unit R is stopped, the receiving unit 141 outputs a reception notification indicating that the signal has been received to the CPU unit 151.
The transmission unit 142 amplifies the signal input from the MODEM unit 13 by a power amplifier (not shown) and outputs the amplified signal to the BPF 143.

Next, the configuration of the base station controller C will be described with reference to FIG.
The base station control apparatus C includes a main control unit 21, a memory 22, a base station interface unit 23, a packet switch unit 24, and a network interface unit 25.

  The main control unit 21 monitors or controls each unit in the base station control device C and the base station device BS connected to its own base station control device C based on a program stored in the memory 22. In addition, setting data for monitoring or controlling each unit and the base station apparatus BS, monitoring result data, and information on the control state of the base station apparatus BS are stored in the memory 22.

  The base station interface unit 23 is connected to the base station device BS via an optical cable or the like, converts an optical signal received from the base station device BS into an IP packet, and outputs the IP packet to the packet switch unit 24. Further, when an IP packet is input from the packet switch unit 24, the base station interface unit 23 converts it into an optical signal and sends it to the base station device BS.

  The packet switch unit 24 exchanges packets of the IP packet input from the network interface unit 25, the IP packet input from the base station interface unit 23, and the IP packet output from the main control unit 21.

  The network interface unit 25 transmits the IP packet output from the packet switch unit 24 to the mobile communication network, and outputs the IP packet to the packet switch unit 24 when receiving the IP packet from the mobile communication network.

  Here, with reference to FIG. 6 and FIG. 7, operation | movement of base station apparatus BS is demonstrated.

FIG. 6 shows the function of the radio processing unit R when a signal received by the antenna ANT is not input for a predetermined time in the radio unit 14 included in the base station apparatus BS, that is, when an uplink signal is not received for a predetermined time. It is a flowchart which shows the process which the control part 15 controls to stop.
In the normal state, the function of the radio processing unit R is activated, and each unit of the base station apparatus BS performs processing. First, the control unit 15 monitors the wireless unit 14. In this monitoring, for example, when a signal is not input to the receiving unit 141 of the wireless unit 14 for a predetermined time, it is determined whether or not a no-reception notification is output from the receiving unit 141 to the control unit 15 (Step S1). S11). When the control unit 15 determines that the no-reception notification is not output, that is, when the control unit 15 does not receive the no-reception notification (NO in step S11), the process of step S11 is continued. When the control unit 15 determines that a notification of no reception is output, that is, when the control unit 15 receives a notification of no reception (YES in step S11), the process proceeds to step S12.

  In step S12, a control signal is output to the OFDM unit 12, the MODEM unit 13, and the radio unit 14 so as to stop the functions of the OFDM unit 12, the MODEM unit 13, and the radio unit 14. In addition, the base station controller C is notified that the functions of the OFDM unit 12, the MODEM unit 13, and the radio unit 14 have been stopped.

FIG. 7 shows that the function of the radio processing unit R is restarted after the function of the radio processing unit R is stopped when a signal received by the antenna ANT is not input for a predetermined time in the radio unit 14 included in the base station apparatus BS. It is a flowchart which shows the process which the control part 15 controls as follows.
This process is started in a state in which the functions of the OFDM unit 12, the MODEM unit 13, and the radio unit 14 are stopped according to the flowchart shown in FIG. First, the control unit 15 monitors the wireless unit 14 and the CPU unit 151 included in the control unit 15 (step S21). The control unit 15 performs monitoring by determining whether or not a reception notification is output from the wireless unit 14 and whether or not the CPU unit 151 has completed the procedure for starting communication of the downlink signal. If the control unit 15 determines that a notification of reception is output from the wireless unit 14 or determines that the procedure for starting communication of the downlink signal is completed in the CPU unit 151 (YES in step S21), the control unit 15 proceeds to step S22. . If it is not determined that the reception notification is output from the wireless unit 14 and it is not determined that the CPU unit 151 has completed the procedure for starting communication of the downlink signal (NO in step S21), the control unit 15 The process of S21 is continued.

  In step S22, a control signal is output to the OFDM unit 12, the MODEM unit 13, and the radio unit 14 so that the functions of the OFDM unit 12, the MODEM unit 13, and the radio unit 14 are resumed. In addition, the base station controller C is notified that the functions of the OFDM unit 12, the MODEM unit 13, and the radio unit 14 have been resumed.

  As described above, when the control unit 15 does not receive an uplink signal for a predetermined time by the receiving unit 141 of the wireless unit 14, the base station apparatus BS performs the operations of the OFDM unit 12, the MODEM unit 13, and the wireless unit 14. The function was stopped. Since the wireless unit 14 includes the transmission unit 142 including a power amplifier corresponding to the antenna ANT, it is possible to suppress power consumption while the power amplifier with high power consumption is not used.

  Further, since the OFDM unit 12 and the MODEM unit 13 are provided corresponding to the antenna ANT similarly to the radio unit 14, when the function of the radio unit 14 is stopped, the OFDM unit 12 and the MODEM unit 13 are simultaneously stopped. It is possible to stop the function. Therefore, in the present embodiment, the wireless unit 14, the OFDM unit 12, and the MODEM unit 13 are formed on the above-described one substrate as the wireless processing unit R. As a result, all the functions formed on one substrate can be stopped, so that power consumption can be further reduced.

  In addition, this invention is not limited to the above structure, A various deformation | transformation is possible. For example, in the above-described embodiment, the case where the radio processing unit R is built in the base station device BS has been described. However, the separated base station (or the distributed installation type base station) in which the radio processing unit R is separated from the base station device BS. A configuration of a base station apparatus called a “station” may be used.

C, C1, C2, C3, C4 ... base station control device, BS, BS1, BS2, BS3 ... base station device, MS, MS1, MS2, MS3 ... wireless terminal device, 11 ... baseband processing unit, 12 ... OFDM unit DESCRIPTION OF SYMBOLS 13 ... MODEM part 14 ... Radio | wireless part 15 ... Control part 21 ... Main control part 22 ... Memory 23 ... Base station interface part 24 ... Packet switch part 25 ... Network interface part R, R1, R2 , Rm: Wireless processing unit, ANT, ANT1, ANT2, ANTm ... Antenna, 141 ... Reception unit, 141T ... Timer, 142 ... Transmission unit, 143 ... Bandpass filter, 151 ... CPU unit, 152 ... Memory, 153 ... Packet generation Decomposition unit, 154... Communication interface unit, 155.

Claims (6)

A wireless communication system comprising a plurality of base station devices that communicate wirelessly with a wireless terminal device, and a base station control device that controls the plurality of base station devices,
At least one of the plurality of base station devices is
A plurality of antennas that transmit and receive wirelessly with the wireless terminal device;
Provided corresponding to each of the plurality of antennas, amplifies the radio signal output from the antenna, and measures the time when the radio signal is not received from the antenna, and when the measured time reaches a predetermined time, A wireless unit that outputs a no-reception notification indicating that the wireless signal has not been received for a predetermined time;
A wireless communication system comprising: control means for controlling to stop at least the function of the wireless unit when the notification of no reception is output.     The wireless communication system according to claim 1, wherein the control unit performs control so as to stop a function related to a board including the wireless unit provided in association with an antenna related to the no-reception notification. The control means includes
The function when the downlink signal is received from the base station control device while the function is stopped in response to the notification of no reception, or when the radio unit receives a radio signal from the antenna The wireless communication system according to claim 1 or 2, wherein the communication is resumed. A base station apparatus of a radio communication system having a plurality of base station apparatuses that communicate with a radio terminal apparatus by radio, and a base station control apparatus that controls the plurality of base station apparatuses,
At least one of the plurality of base station devices is
A plurality of antennas that transmit and receive wirelessly with the wireless terminal device;
Provided corresponding to each of the plurality of antennas, amplifies the radio signal output from the antenna, and measures the time when the radio signal is not received from the antenna, and when the measured time reaches a predetermined time, A wireless unit that outputs a no-reception notification indicating that the wireless signal has not been received for a predetermined time;
A base station apparatus comprising: control means for controlling to stop at least the function of the radio unit when the notification of no reception is output.     The base station apparatus according to claim 4, wherein the control unit performs control so as to stop a function related to a board including the radio unit provided in association with an antenna related to the no-reception notification. The control means includes
The function when the downlink signal is received from the base station control device while the function is stopped in response to the notification of no reception, or when the radio unit receives a radio signal from the antenna The base station apparatus according to claim 4 or 5, wherein the base station apparatus is restarted.

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