JP2009111968A - Combined communications system, prohibiting-signal transmitting apparatus, wireless base station, and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To utilize frequencies effectively when old and new communication systems using system bands at least partly overlapped coexist. <P>SOLUTION: A prohibiting-signal transmitting apparatus is used in a combined system in which at least a part of a system band of an old communication system overlaps that of a new communications system. The prohibiting-signal transmitting apparatus includes: a means monitoring which band is in use while communication is actually conducted, out of the bands allocated to the old communications system; a means generating a prohibiting signal indicating that the band in use should not be used in the new communications system; and a means notifying a communications apparatus in the new communications system of the prohibiting signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a composite communication system having a plurality of old and new communication systems in which at least a part of a system band overlaps, a prohibition signal transmission apparatus, a radio base station and a method.

  Wireless communication is used in various applications such as mobile phones, wireless LANs, broadcasting (terrestrial and satellite), radar, and positioning. In addition to these existing systems, new terms such as Long Term Evolution (LTE), which is a standard developed from the 3rd generation mobile communication system that is being studied in 3GPP, and 4th generation systems, etc. It is expected that frequency allocation for the system will also be considered. Furthermore, with the recent increase in the speed of mobile communication systems, the bandwidth required for allocation tends to increase.

  On the other hand, radio frequency resources are finite, and frequency usage is not necessarily the same depending on the country or region. Considering such a situation, it will not be easy to allocate a wide band exclusively to all countries and all value ranges exclusively for new systems in the future. Furthermore, since the propagation characteristics differ depending on the frequency band, the required degree of freedom in frequency band allocation is limited to some extent depending on the application, and it is expected that frequency allocation will become more difficult.

  Therefore, even in the currently used frequency band, by incorporating a mechanism that does not affect the existing system, it is possible to assign a frequency to the new system and to use the frequency more efficiently. It may be.

  The conventional method described in Non-Patent Document 1 and the like is a frequency sharing technique between old and new systems, such as UWB, spatially limits the use of the new system indoors, and is fixed according to the existing system. The transmission power level is limited.

The method described in Non-Patent Document 2, etc., detects signals for a certain period of time before sending traffic data and confirms whether or not the existing system is using that bandwidth, like the IEEE802.11h standard DFS. Then, transmission is performed using a band not used by the existing system.
Ultra-wideband radio technology: potential and challenges ahead Porcino, D .; Hirt, W .; Communications Magazine, IEEE Volume 41, Issue 7, July 2003 Page (s): 66-74 IEEE 802.11 WG, Part 11: Wireless LAN Media Access Control (MAC) and Phisical layer (PHY) specifications, Amendment 5: Spectrum and Transmit Power Management Extensions in 5 GHz band in Europe, Oct. 2003

  As shown in Non-Patent Document 1, in the method in which the place where the frequency band is used and the transmission power level are fixedly limited, even when there is no existing system terminal that may be subject to interference, The use place and transmission power level are limited, which is not desirable from the viewpoint of effective use of frequencies. In particular, there is a concern that the frequency resources that can be used in the new system will be very limited when the frequency usage situation varies from region to region, or when an existing communication system that is not frequently used uses various bands. .

  Furthermore, as shown in Non-Patent Document 2, with respect to a method for detecting whether or not an existing system is being used in the surroundings and avoiding interference, a case where the existing system is a broadcast receiver or a satellite In the case of a system receiver or the like, it is difficult to effectively avoid interference. This means that the resources that can be allocated to the new system are very limited. The reason is that, for example, the operation of the new system will be limited in the entire broadcasting area, but if so, it will be very large regardless of whether the receivers of the existing system are operating around each transmitter. This is because the operation of the new system is restricted over the entire area. This is also undesirable from the viewpoint of effective use of frequency. Furthermore, even if the operation of the receiver of the existing system is to be detected, the receiver of the broadcast system itself does not transmit a signal, so that it is difficult to properly detect the receiver of the broadcast system in the new system.

  An object of the present invention is to effectively use a frequency when a plurality of new and old communication systems in which at least a part of a system band overlaps coexist.

  The prohibition signal transmitting apparatus used in the present invention is used in a complex system in which at least a part of the system band of the old communication system overlaps the system band of the new communication system. The prohibition signal transmitting device includes means for monitoring what band is actually used in communication among the bands allocated to the old communication system, and the use band is used in the new communication system. A prohibition signal transmission apparatus comprising: a means for creating a prohibition signal indicating that it should not be, and a means for notifying the prohibition signal to a communication apparatus of the new communication system.

  ADVANTAGE OF THE INVENTION According to this invention, when a some old and new communication system with which at least one part of a system band overlaps exists, effective utilization of a frequency can be aimed at.

  FIG. 1 shows a system configuration assumed in this specification. Here, it is assumed that the band used by the satellite broadcasting system as the existing system and the system band allocated to the communication system as the new system at least partially overlap.

  Since the use of the frequency of the existing allocation system should be prioritized, the new system needs to operate without interference to this satellite system.

  In the method shown in the present embodiment, an interference notification signal transmission apparatus that is a “forbidden signal transmission apparatus” is installed in the vicinity of a receiver of an existing system. This interference notification signal transmitting apparatus transmits an interference notification signal that is a “forbidden signal” to the new system, thereby requesting the new system to refrain from using a part of the band. On the other hand, the new system can monitor the interference notification signal transmitted from the interference notification signal transmitter, and can freely use the band allocated to the new system only when this interference notification signal is not detected. Here, the interference notification signal is assumed to be performed using a channel prepared exclusively for transmission of this signal.

  In FIG. 1, the receiver and the interference notification signal transmission device of the existing system are prepared separately, but these may be provided in the same device, a common antenna may be used, or separate. The antenna may be used. Furthermore, a plurality of antennas having the same directivity may be used.

  FIG. 2 shows a format example of the interference notification signal. The preamble is a prescribed signal pattern, and is used for signal detection and channel estimation in the interference notification signal detection unit of the new system base station. The use restriction request band indicates an ID corresponding to a band for which use restriction is requested.

  Further, the interference notification signal may include an interference notification signal transmitter ID, a required improvement amount, an allowable absolute transmission level, and the like. Further, although not shown, an error detection bit may be added to each of the use restriction request band, the interference notification signal transmitter ID, or the like, or one error detection bit may be included in several information items. A bit may be added. Similarly, error correction coding may be performed in some appropriate information unit.

  FIG. 3 shows the configuration of the interference notification signal transmitter 30. The setting recording unit 31 stores a band and the like for which the interference notification signal transmitting apparatus requests use restriction. Based on these pieces of information, the interference notification signal generator 32 generates an interference notification signal. The interference notification signal is modulated to a predetermined frequency by the radio circuit unit 33 and transmitted.

  As described above, the base station of the new system receives the interference notification signal and operates based on these signals. Then, all the interference states can be grasped by the base station, and the channel used in the existing system is not used. The channel used in the existing system may be referred to as a “use band” from the viewpoint of the existing system, or may be referred to as a “use limited band” from the viewpoint of the new system. By prohibiting the allocation of the use band to the uplink channel, it is not essential to provide a detection unit related to the interference notification signal in the terminal of the new system or to perform an operation according to the detection result. In addition, the new system needs to have specifications that can operate without using the bandwidth designated as the bandwidth used by the existing system. From such a viewpoint, it is advantageous to use the OFDM modulation system. This is because the frequency to be used can be changed easily and flexibly by using the OFDM modulation method. In the following description, it is assumed that the OFDM modulation scheme is applied.

  FIG. 4 shows a configuration example of the base station of the new system. The signal received by the radio circuit unit depicted on the right side in the figure is separated into a signal that may contain an interference notification signal and a signal of a new system. A signal that may contain the interference notification signal is input to the interference notification signal detection unit.

  When the interference notification signal is included in the received signal, the interference notification signal detection unit determines the use limited band from the interference notification signal, and notifies the resource allocation unit of the determination result. As described above, the use limited band is a band used for actual communication in the existing system.

  The resource allocation unit performs resource allocation for the uplink channel and the downlink channel using a band other than the band set as the use limited band. In the band actually used in the existing system, it is necessary for the base station of the new system not to transmit not only normal data signals but also all signals such as preambles and pilot signals. Note that the resource allocation unit may be called a scheduler because it performs scheduling of radio resources. The pilot signal may be a reference symbol (RS), a training sequence, a known signal, or any other appropriate signal known before communication.

  The data signal generation unit generates a transmission signal from the input transmission data, information from the resource allocation unit, and the like, and outputs the transmission signal to the multiplexing unit.

  The control signal generation unit generates a control signal to be transmitted based on the system parameters and information from the resource allocation unit, and outputs the control signal to the multiplexing unit.

  The multiplexing unit multiplexes the input data signal and the control signal based on resource input information that is also input. Also, pilot signals are multiplexed.

  These signals are input to the OFDM modulator, and a time signal to be transmitted is generated. This time signal is input to the radio circuit unit, modulated to the frequency to be transmitted, filtered, and power amplified, and the resulting signal is transmitted.

  FIG. 5 shows a configuration example of the interference notification signal detection unit. The preamble detector determines whether or not a preamble is included in the received signal. Here, when the signal received as the preamble does not reach the predetermined reception level, the subsequent operation is not performed. When the preamble is detected, the subsequent operations are started.

  First, channel estimation is performed in the channel estimation unit. Then, using the channel estimation value estimated by the channel estimation unit, the equalization unit performs reception signal equalization processing. The received signal subjected to equalization processing is input to the demapping unit, and received bits are detected from the received symbols. The detected received bit sequence is subjected to error correction decoding by the subsequent FEC decoding unit, and the decoding result is input to the CRC unit. The CRC unit detects whether or not an error is included in the input signal sequence. The presence / absence of an error is input to the use bandwidth limiter.

  In the transmitter information storage unit, the transmission power and the out-of-band radiation amount of the own transmitter may be set and input to the use limited band determination unit, and the necessary guard bandwidth may be calculated from these values.

  In the use restricted band determination unit, the band notified by the interference notification signal is set as the use restricted band. Here, when the interference notification signal is received but cannot be received correctly (for example, when the CRC error determination result is NG), the use of all the bands should be restricted. Also good.

<Numerical example>
Hereinafter, specific numerical examples are shown to facilitate understanding of the present invention, but these numerical values are merely examples, and any appropriate numerical values may be used within the scope of the present invention. The following calculations are all shown as calculation formulas in dB.

  (1) The condition that the signal transmitted from the new system base station is below the allowable level at the existing system receiver can be expressed as follows, for example.

P _BS −BW _BS + G _BS-RO −PL _BS-RO + G _RO-BS <NL _RO + I / N (A1)
Here, each symbol represents the following quantity.

P _BS : New system base station transmission power [dBm]
BW _BS : New signal base station transmission signal bandwidth [dBHz]
G _BS-RO : Antenna gain [dB] in the direction of the existing system receiver of the new system base station
PL _BS-RO : Propagation attenuation [dB] between the new system base station and the existing system receiver
G _RO-BS : Antenna gain [dB] toward the new system base station of the existing system receiver
NL _RO : Existing system receiver noise level [dBm]
I / N: Permissible interference power to noise power ratio [dB].

  (2) The conditions under which the signal transmitted from the interference notification signal transmitter is received by the new system base station can be expressed as follows, for example.

P _IBD -BW _IBD + G _IBD-BS -PL _IBD-BS + G _BS-IBD + Nrep> NL _BS + I _margin + C / N _req (A2)
Here, each symbol represents the following quantity.

P _IBD : Transmission power [dBm] of the interference notification signal transmitter
BW _IBD : Signal bandwidth [dBHz] of interference notification signal transmission signal
G _IBD-BS : Antenna gain [dB] in the direction of the new system base station of the interference broadcast signal transmitter
PL _IBD-BS : Propagation attenuation [dB] between the interference notification signal transmitter and the new system base station
G _BS-IBD : Antenna gain [dB] in the direction of interference notification signal transmitter of new system base station
NL _BS : New system base station Noise level [dBm / Hz]
I _margin : Interference margin [dB]
C / N _req : Required received power to noise power ratio [dB]
Nrep: Number of repeated transmissions.

  (3) The condition that the signal transmitted from the interference notification signal transmitter is below the allowable level of the existing system receiver can be expressed as follows, for example.

P _IBD −ACLR−BW _IBD + G _IBD-RO + PL _IBD-RO + G _RO-IBD <NL _RO + I / N (A3)
Here, each symbol represents the following quantity.

P _IBD : Transmission power [dBm] of the interference notification signal transmitter
ACLR: Adjacent channel power ratio [dB]
BW _IBD : Signal bandwidth [dBHz] of interference notification signal
G _IBD-RO : Antenna gain [dB] in the direction of the existing system receiver of the interference notification signal transmitter
PL _IBD-RO : Propagation attenuation [dB] between the new system base station and the interference notification signal transmitter
G _RO-IBD : Antenna gain [dB] in the direction of interference notification signal transmitter of existing system receiver
NL _RO : Existing system receiver noise level [dBm]
I / N: Permissible interference power to noise power ratio [dB]
(4) Under the above conditions, a numerical example in the case of assuming a general television receiver as an existing system receiver is shown below.

The path loss necessary for the amount of interference to satisfy the permissible level is from equation (A1)
P _BS −BW _BS + G _BS-RO + G _RO-BS −NL _RO −I / N
= 36−80 + 15 + 5 − (− 166) − (− 10)
= 152 [dBm / Hz] <PL _BS-RO
It becomes. Here, the value of each parameter was set to the following value.

P _BS = 36dBm (4W)
BW _BS = 80dBHz (100MHz)
G _BS-RO = 15dB
G _RO-BS = 5dB
NL _RO = −166dBm
I / N = −10dB
152 [dBm / Hz] <PL _BS-RO required transmission power of interference notification signal is
Assuming that PL _BS-RO = PL _IBD-BS
P _IBD >
NL _BS + C / N _req + BW _IBD −G _IBD-RO + PL _IBD-BS −G _RO-IBD −Nrep
= -170 + 3 + 50-10 + 152-12-12
= 1dBm
It becomes. Here, the value of each parameter was set to the following value.

NL _BS = −170dBm
CN _req = 3dB
BW _IBD = 50dBHz (100kHz)
G _IBD-RO = 10dB
G _BS-IBD = 12dB
Nrep = 12dB
Finally, the amount of interference received by the existing system receiver when transmitting an interference notification signal with transmission power P _IBD is
P _IBD −ACLR−BW _IBD + G _IBD-RO + PL _BS-IBD + G _RO-IBD
= 1-70-50-5-56-3
= -183dBm / Hz <-178 = NL _RO + I / N
And can be made below the allowable level. Here, the value of each parameter was set to the following value.

ACLR: 70dB
BW _IBD : 50dBHz (100kHz)
G _IBD-RO : -5dB
PL _BS-IBD : -56dB (assuming a separation distance of about 3m in a straight line)
G _RO-IBD : -3dB
However, in practice, it is impossible to accurately grasp the transmission power, propagation loss, etc. of the new system base station, and a sufficient margin may be set in preparation for this.

<CSMA>
FIG. 7A shows a situation in which collision of interference notification signals is likely to occur when the geographical density of the interference notification signal transmission device is increased. In the illustrated example, signal B and signal C collide. For this problem, CSMA / CA, which is a conventionally proposed interference avoidance technique, or a method of transmitting in slots may be used.

  When a CSMA-based method is used, the surroundings are monitored before a signal such as traffic data is transmitted to check whether an interference notification signal is transmitted in the surroundings. When the interference notification signal is transmitted around, the transmission of the interference notification signal from the own station is postponed until the next transmission opportunity (FIG. 7B). On the other hand, when the interference notification signal is not transmitted around, the interference notification signal is transmitted from the own station.

<Slotting>
Slotting is a method in which the interference notification signal transmitting apparatus unifies and arranges the transmission start timing of the interference notification signal so that the reception side can separate simultaneous reception signals into individual signals using a signal separation technique. In order to perform slotting, it is necessary to synchronize between interference notification signal transmitting apparatuses. This may be synchronized using, for example, GPS. By performing slotting, partial collision that makes signal separation difficult can be avoided, and the probability of collision failure and reception failure can be reduced. Further, since the reception timing can be specified to some extent, it is considered that there is an effect of facilitating reception at the new system base station.

  Further, once the transmission is successful, the interference notification signal is periodically transmitted at a predetermined period. The transmission at this timing is considered to be reserved, and the other interference notification signal transmission apparatuses perform interference at other timing. You may make it start transmission of an alerting | reporting signal.

In addition, since it is only necessary to synchronize locally in this method, the synchronization may be ensured by transmitting in accordance with the transmission timing of the surrounding interference notification signal transmitting apparatus. In addition, in order to synchronize locally, it is necessary that interference notification signal transmission devices exist at least in the surroundings, but if there are not a plurality of such devices, When an interference notification signal is not received, each terminal may transmit a signal at an arbitrary timing.
<Synchronous + CSMA>
Furthermore, CSMA and slotting may be used in combination. However, when synchronizing locally according to the transmission situation of the surrounding interference notification signal, it is necessary to adjust the transmission timing of the interference notification signal as shown in Method 1 or Method 2 below. This is because when slotting is performed, it is necessary to unify the time used as a reference for transmission timing, while CSMA attempts to realize backoff randomization.

(Method 1)
As shown in FIG. 8, the postamble is added after the interference notification signal so that the sum of the length of the postamble and the backoff is constant. The transmission start timing is determined with the postamble transmission end time as the reference timing.

(Method 2)
As shown in FIG. 9, a signal for notifying the start of transmission is transmitted before the preamble with reference to the transmission timing of the preamble signal. Further, the sum of the signal indicating the start of transmission and the back-off time is maintained constant.

  In the above two examples, since frame 2 starts transmission first, frame 2 gets the transmission right, frame 2 is transmitted, and frame 1 is transmitted at the next opportunity.

  In the case of locally synchronizing as described above, there is a possibility that a case where the interference notification signal is received synchronously and a case where the interference notification signal is received asynchronously are mixed.

  In such a situation, the new system base station may prepare a synchronous reception mode and an asynchronous reception mode and operate as follows.

  In the synchronous reception mode, the base station specifies the next frame start timing at a locally calculated timing, and starts the frame reception process described above when the frame reception start timing comes. At this time, the correction of the locally calculated timing may be corrected based on the preamble detection timing. Further, after detecting all signals at the specified timing, a replica of the received signal is created, and the power after canceling this replica from the received signal is confirmed. If the synchronization is ensured, the power after cancellation is small, but if not, considerable power remains. Therefore, if this power is equal to or greater than the predetermined value, the mode transits to the asynchronous reception mode.

  In the asynchronous reception mode, the correlator for each spreading code is always operated and the correlation output is monitored. In the asynchronous reception mode, when an interference notification signal is received only at a predetermined timing for a predetermined time or more, a transition is made to the synchronous reception mode. At this time, the specified synchronization timing is not limited to one, but may be two or more.

  Since the interference notification signal restricts the use of radio resources in the new system base station, it is not preferable that the interference notification signal is transmitted more than necessary from the viewpoint of efficient use of frequency. Furthermore, the existing system is also not preferable in terms of wasting power in the interference notification signal transmission apparatus of the existing system and increasing the probability of collision between interference notification signals.

  In the third embodiment of the present invention, the interference notification signal transmitting apparatus transmits the interference notification signal only when the corresponding existing system receiver is operating, and does not transmit the interference notification signal if it is not operating. Like that. Therefore, the interference notification signal transmitting apparatus needs a function for determining whether or not the existing system receiver is operating. This function can be realized by the following method.

  One of the implementation methods is to determine whether or not the receiver is powered by the amount of power supplied to the antenna of the existing system receiver (FIG. 10) or the amount of power supplied to the tuner (see FIG. 11) To judge.

  When measuring the amount of power supplied to the tuner, the power consumption amount of these devices is not always constant even during operation, so the threshold value of the power amount is the maximum value of standby power and Should be set in the middle of the lowest minimum power. This threshold value may be determined manually or may be determined dynamically. Further, what is used for the determination may not be an instantaneous power value, but may be an averaged value over time. Further, when the tuner is turned on, the determination as to whether or not the tuner is turned off may not be always confirmed, but may be confirmed at regular intervals.

  By the way, when the existing system is a broadcast system, generally, many broadcast channels are simultaneously transmitted in parallel, and the existing system receiver receives one of them (in some cases, two or more). . These broadcast channels are transmitted separately by frequency division multiplexing such as bands A, B, and C.

  The above method based on the operating state (ON / OFF) of the receiver of the existing system makes it easy to use the interference notification signal transmission apparatus for the existing system receiver manufactured without considering the interference notification according to the present invention. This is advantageous in that it can be implemented. However, since only the ON / OFF of the existing system receiver is considered, all the bands that can be used by the existing system receiver cannot be used by the new system (FIG. 12).

  Focusing on the difference in the frequency band of the broadcast channel, the frequency utilization efficiency can be further improved by restricting only the individual frequency band received by the existing system receiver at each time point with the new system. (FIG. 13). In FIG. 13, it is recognized that only band B is actually used, and bands A and C are not used in the existing system.

  When limiting only the band (band B in FIG. 13) received by the existing system receiver corresponding to the interference notification signal transmission device, the interference notification signal transmission device may be operated as follows. That is, while the existing system receiver is operating, the interference notification signal transmission device may be notified of the currently received band, or when the user starts use and switches the broadcast channel, The broadcast channel may be notified to the interference signal notification device, and the interference signal notification device may identify the band currently used. Then, an interference notification signal is transmitted so as to restrict use of only this band.

  Further, even when two broadcast channels are received simultaneously, the band corresponding to the two currently received broadcast channels may be prohibited.

  In addition, a plurality of bands are generally prepared not only in a broadcasting system but also in a communication system, and a terminal performs communication using one of these, and thus the above method can be applied.

The fourth embodiment of the present invention improves the efficiency of notification of interference signals. FIG. 14 is a schematic block diagram of the interference notification signal device 140 according to the embodiment of the present invention. The setting recording unit 141 stores a band or the like for which usage restriction is requested, and is connected to the interference notification signal generation unit 142. The radio circuit unit 143 is connected to the antenna, the interference signal receiving unit 145, and the interference notification signal generating unit 142. The radio circuit unit 143 amplifies the radio signal received from the antenna and sends it to the interference signal receiving unit 145. The interference signal receiving unit 145 amplifies a signal in a band to be monitored among the received signals and sends the amplified signal to the transmission control unit 144. The interference notification signal generation unit 142 generates a transmission signal of the interference notification signal based on information from the transmission control unit 144 and the setting recording unit 141, and sends the signal to the radio circuit unit 143. The radio circuit unit 143 modulates the transmission signal to a predetermined frequency and transmits it.

In the interference notification signal transmitting apparatus, the interference notification signal is transmitted only when the interference signal is received. Here, whether or not an interference signal is received is determined by measuring not only the frequency band currently used by the existing system receiver but also the interference signal reception power in the frequency band of the entire new system. .

As shown in FIG. 15, it is assumed that the interference notification signal transmission apparatus monitors only the frequency band B received by the existing system receiver. In this case, the following situations are possible:
1. The interference notification signal transmission is notified to the new system base station.

  2. The new system base station stops transmitting in the band (usage limited band B) specified by the interference notification signal.

  3. In the limited use band A, no interference signal is received. As a result, the interference notification signal transmitter stops transmitting the interference notification signal.

  4). Since the new system base station does not receive the interference notification signal prohibiting the use of the use restriction band B, the new system base station resumes transmission using the use restriction band A.

  5). The interference notification signal transmitting apparatus detects that interference has occurred in the use restricted band B, and transmits the interference notification signal to the new system base station again.

  As described above, there is a concern that the existing system receiver may periodically receive interference in the use restricted band A due to the inefficient transmission of the interference notification signal.

  The fourth embodiment tries to cope with such a problem. Not only the band currently received by the existing system receiver but also received signals in other bands are included in the monitoring target. As a result, it is possible to determine whether or not there is a transceiver of the new system around the existing system (whether or not communication is performed). When there is a transmitter / receiver of a new system, even if there is no interference signal in the band used for reception by the existing system receiver, an interference notification signal for prohibiting use of that band is periodically sent to the new system base. By transmitting to the station, the above concerns can be addressed.

  Further, by allowing the interference notification signal transmitting apparatus to recognize the interference level, the transmission output of the interference notification signal, the spreading factor of the interference notification signal, and the like may be adaptively determined. For example, at the initial transmission, a predetermined level or spreading factor is used, but if the received interference signal level does not fall to an allowable level, the transmission power may be increased or transmission may be increased. May be.

  The measurement of the interference level may be performed by the interference notification signal transmission device, or the existing system receiver may measure the interference level and notify the interference notification signal transmission device.

  There is a concern that interference may occur when a mobile terminal belonging to a new system that has moved from outside the service area of the interference notification signal newly starts transmission.

  This problem can be solved by giving the mobile terminal a provisional transmission period described in Example 7 to be described later. A mobile terminal that intends to transmit a signal transmits a signal in advance during this temporary transmission period. The signal transmission in this temporary transmission period may be in a frequency band that is not used by the existing system receiver, or may be received in advance in the frequency band that is used by the existing system receiver. A time when the machine is not in use may be provided and transmitted during this time period. In the temporary transmission period, each existing system receiver observes the signal and determines whether or not to transmit the interference notification signal depending on whether or not the signal is transmitted in the temporary transmission period. .

  There may be only one interference notification signal transmitter, or a plurality of interference notification signal transmitters. The fifth embodiment of the present invention relates to efficiently reporting an interference notification signal to a new system when there are a plurality of interference notification signal transmitters. For example, it is assumed that there are two interference notification signal transmitters A and B and one new system base station C. If the interference notification signals prepared by the interference notification signal transmitters A and B are the same, it is not efficient to separately notify the interference notification signals to the new system base station. Therefore, for example, when the interference notification signal transmitted from the interference notification signal transmitter A is received by the interference notification signal transmitter B and indicates the same band as the interference notification signal transmitter B, the interference notification signal The transmitting apparatus B may not transmit the interference notification signal. However, in this method, depending on the positional relationship between the interference notification signal transmitter and the new system base station, interference that cannot be ignored may occur in the existing system.

  As shown in FIG. 16, it is assumed that there are two interference notification signal transmitters and one new system base station. The new system base station cannot receive the interference notification signal emitted from the interference notification signal transmitter A, but can receive the interference notification signal emitted from the interference notification signal transmitter B. When the interference notification signal from the interference notification signal transmitting apparatus B indicates the same band X as the interference notification signal transmitting apparatus B intends to notify as in the above operation, the interference notification signal transmitting apparatus B Suppose you decide not to send a signal. In that case, the new system base station C will not receive the interference notification signal, and may perform some communication using the band X. As a result, there is a concern that interference from the new system may occur in the band X.

  The fifth embodiment of the present invention addresses this problem. The interference notification signal transmission device B confirms the reception level of the interference notification signal received from the interference notification signal transmission device A. When this reception level is high, the interference notification signal transmitter B does not transmit the interference notification signal. When the reception level is low, the interference notification signal transmission apparatus B transmits an interference notification signal. The magnitude relationship between the reception levels may be made by comparing with a predetermined threshold. By deciding whether or not to transmit an interference notification signal from the own device based on the magnitude relationship of the reception levels of interference notification signals from other devices, the above problem can be effectively dealt with. When the interval between the interference notification signal transmission devices A and B is close to some extent, the interference notification signal transmission device B refrains from transmitting the interference notification signal. The interference notification signal is transmitted from the interference notification signal transmitting apparatus B only when the interval is considerably separated.

  Further, the interference notification signal transmission apparatus B may determine whether or not to transmit the interference notification signal in consideration of the reception level of the interference signal. For example, when the reception level of the interference notification signal received from the other device A is low and the interference level at the own device B is high, the interference notification signal is transmitted. Otherwise, the interference notification signal is not transmitted. You may do it. For example, in the case shown in FIG. 16, when the interference notification signal transmitter B and the new system base station C are largely separated and the interference level from the new system is low, the interference notification signal transmitter B The broadcast signal is not transmitted. By doing so, the limitation of the band used in the new system can be narrowed down to only what is really necessary, while the transmission of the interference notification signal can be limited to only what is really necessary.

  Note that, as shown in FIG. 17, the interference notification signal transmission device B has already transmitted the interference notification signal Y with respect to the use of the use restriction band X (band X) (not shown). When transmission of an interference notification signal is refrained, the following situation can be considered. Even when the transmission of the interference notification signal Y from the interference notification signal transmission device A is stopped, the interference notification signal transmission for which the existing system has refrained from transmitting the interference notification signal in order to continue using the band X. In some cases, the device B has to start transmission of the interference notification signal, but before that, the new system base station C may start transmission. That is, as shown in FIG. 18, before the interference notification signal transmitting apparatus B transmits the interference notification signal, a signal is transmitted from the new system base station C. As a result, interference from the new system base station C in the band X occurs. There is a concern that it will occur.

  In order to cope with such a problem, as shown in FIG. 19, the interference notification signal transmitter B always monitors the interference notification signal Y transmitted from the adjacent interference notification signal transmitter A, and the new system base The station C may proceed to an operation of starting signal transmission after waiting for a predetermined period (“transmission waiting time” in FIG. 19) after stopping the reception of the interference notification signal Y. In this way, the interference notification signal transmission apparatus B can transmit the interference notification signal before starting the signal transmission of the new system base station C, and the new system base station C The existing system can continue to receive the desired signal without suffering from the interference.

  In each of the above-described embodiments, an interference notification signal transmission apparatus different from the new system base station creates and transmits an interference notification signal. However, the present invention is not limited to such a form. For example, the new system base station may determine whether or not the band can be used, or may create and transmit an interference notification signal. By providing such a function in the new system base station, the number of interference notification signals is reduced (reducing collisions) when the geographical arrangement density and operating rate of the interference notification signal transmitters are high, and the existing system and the new system The effective use of the frequency is planned.

  First, it is assumed that the interference notification signal transmitting apparatuses (for example, A and B in FIG. 16) already described in the above embodiment and the new system base station of this embodiment are mixed. The base station according to the present embodiment broadcasts a band that is refrained from use in the area of the base station (usage limited band X) as a limited band notification signal based on the current state of interference notification and information set in advance. The new system uses a band other than the limited use band X. When the band X actually used in the existing system is included in the use restricted band, the interference notification signal transmission apparatus does not transmit an interference notification signal for requesting prohibition of use of the band X. This is because the notification has already been made with the limited band broadcast signal from the new system base station. On the other hand, the interference notification signal transmitting apparatus transmits the interference notification signal only when the band used in the existing system is not included in the use restricted band.

  In the present embodiment, the interference notification transmission apparatus operates as follows.

  1. It is determined whether or not an interference notification signal for requesting prohibition of use of the band X actually used in the existing system is transmitted from the base station (whether or not it is in the limited band notification mode). The operation mode may be determined based on whether or not a limited band notification signal is received from the new system base station.

  2. When the operation mode of the base station is not the limited band notification mode, the operation already described in the above embodiment is executed, and the interference notification signal is transmitted.

  3. When the operation mode of the base station is the limited band notification mode, the interference notification signal transmitting apparatus analyzes the limited band notification signal from the new system base station and identifies a band that is refrained from being used in the new system. It is determined whether or not the band corresponds to a band for which prohibition is requested by the interference notification signal transmitting apparatus. If not applicable, the interference notification signal transmitting apparatus performs the operation already described, and transmits the interference notification signal. When it corresponds, an interference alert signal transmission device does not transmit an interference alert signal.

  FIG. 20 shows a device configuration example of an interference notification signal transmitting device used in this embodiment.

  The limited band broadcast signal receiving unit receives the limited band broadcast signal transmitted from the new system base station, confirms the presence and content of the limited band broadcast signal, and notifies the transmission control unit of the result.

  The limited band broadcast signal may be broadcast in a dedicated band, or may be transmitted in the same band as the interference broadcast signal.

  The transmission control unit determines the necessity of transmission of the interference notification signal based on the information input from the limited band notification signal reception unit and the information from the setting storage unit, and controls the operation of the interference notification signal generation unit To do.

  In this embodiment, the base station (or terminal) of the new system needs to perform the following operation in addition to the above operation.

  1. Determining the necessity of transition to the limited band notification mode.

  2. Stop the bandwidth allocation.

  3. Notifying a surrounding base station and / or an interference notification signal transmitting apparatus of a band limitation notification signal (interference notification signal).

  4). Confirming the operation mode switching event (for example, determining the end of the limited band notification mode).

  The determination of when to start the limited band notification mode may be determined by the following determination criteria as an example.

  The timing and frequency band for starting the limited band notification mode are manually determined in advance.

  Determined according to the transmission status (number of sources, transmission period, etc.) of detected interference notification signals.

  -Determined by the collision frequency of the detected interference notification signal.

  ・ Determine based on the system load of the new system.

  The determination of when to end the limited band notification mode may be canceled after a certain time after the start of the limited band notification mode, for example. However, in this method, in addition to the possibility that the limited bandwidth notification mode may be set unnecessarily for a long time, on the other hand, if it is short, the frequency of starting and ending the limited bandwidth notification mode is high. There is a possibility of becoming. This is because the interference notification signal related to the band is not transmitted from the interference notification signal transmitting device during the limited-band notification mode, so the operation status of the existing system cannot be properly determined, and the mode switching timing is appropriately set. It is because it becomes impossible to judge.

  From the viewpoint of dealing with such concerns, even when the new system base station is in the limited band notification mode, the interference notification signal may be transmitted from the interference notification signal transmission device at a constant interval. . The fixed interval in this case should be set longer than the interval at which the normal interference notification signal is transmitted. This fixed interval needs to be set in consideration of the interval for determining the timing at which the base station cancels the limited band notification mode. Further, regarding a certain interval, a signal transmitted from another interference notification signal transmitting device A around the interference notification signal transmitting device B is requested to prohibit use of the same band that is actually used by the interference notification signal transmitting device B. In such a case, the signal may be transmitted from the interference notification signal transmitting apparatus B after a predetermined time from the transmission time of the signal. The determination of surrounding interference notification signal transmitters may be made using the method described above. In addition, the base station may notify the predetermined interval. In this case, the interference notification signal transmitting apparatus needs a function of receiving the notification signal in addition to the function of analyzing the content of the limited band notification signal.

  Further, the interference notification signal transmission apparatus may transmit the interference notification signal at regular intervals during the limited band notification mode, or transmit the interference notification signal irregularly or as necessary. For example, the new system base station may transmit a signal “prompt an interference notification signal related to a limited band”, and each interference notification signal transmission device may transmit the interference notification signal in response to this signal. At this time, in the interference notification signal transmitting apparatus, in order to determine the operating status of the terminals of the surrounding new system, as described above, the reception signal level in a band other than the limited band may be checked.

  The transmission of the limited band notification signal may be performed by a device other than the base station, but is preferably performed by the new system base station.

  In the seventh embodiment, as shown in FIG. 21, there is a concern that a signal is transmitted from a new system base station D other than the new system base station C that has transmitted the limited band notification signal and suffers interference. That is, as shown in FIG. 22, there is a possibility that a signal is also transmitted from the new system base station D during a period in which the new system base station C is transmitting the limited band notification signal.

  There are several ways to address these concerns: That is, a certain temporary transmission period may be provided as shown in FIG. The new system base station D that intends to transmit a signal transmits a signal in advance during this temporary transmission period. The signal transmission in this temporary transmission period may be in a frequency band that is not used by the existing system receiver, or may be received in advance in the frequency band that is used by the existing system receiver. A time when the machine is not in use may be provided and transmitted during this time period. In the temporary transmission period, each existing system receiver observes the signal and determines whether or not to transmit the interference notification signal depending on whether or not the signal is transmitted in the temporary transmission period. . In this way, signal transmission from the new system base station D can be suppressed after the temporary transmission period, and interference can be avoided.

  When a certain interference notification signal transmission apparatus transmits an interference notification signal and another surrounding interference notification signal transmission apparatus transmits an interference notification signal, the signals collide. This collision also occurs between the limited band notification signal and the interference notification signal transmitted from the new system. Hereinafter, a description will be given of a collision between interference notification signals as an example. If an interference notification signal is to be detected, it may not be detected correctly. In the above, the method of reducing the probability that the interference notification signal collides has been described. The seventh embodiment of the present invention improves the probability that the interference notification signal can be correctly received even after the interference notification signal collides. For this reason, the interference notification signal is spread and transmitted. The spreading code used here may be selected as follows as an example.

  ・ Select at random.

  -Detect spreading codes used in the surroundings and use unused codes.

  Detects spreading codes used in the surroundings, and selects a code taking into account the band X in which the device requests use restriction and the band Y in which use prohibition is required in the surroundings (details are shown below) ).

  Further, as described above, when the transmission timing is standardized and the transmission is successful once, the same signal is transmitted at a constant interval, and the spreading code may be selected as follows. .

  FIG. 24 shows an interference notification signal transmitter 240 used in the seventh embodiment of the present invention. The interference notification signal transmission device 240 detects a spreading code used around its own device and determines a spreading code to be used. In the present embodiment, in addition to the configuration of the interference notification signal transmitting apparatus 30 described above, a spreading unit 245, a spreading code selection unit 242, and a notification signal receiving unit 243 are separately required.

  The radio circuit unit 246 is connected to the antenna, the spreading unit 245, and the notification signal receiving unit 243. The radio circuit unit 246 amplifies the radio signal received from the antenna and sends it to the notification signal receiving unit 243. The broadcast signal receiving unit 243 detects a band whose use is restricted by these signals, in addition to detecting spreading codes used in the surroundings, from the received broadcast signal.

  The setting recording unit 241 stores a band or the like for which the interference notification signal transmission device 240 requests use restriction. Further, the setting recording unit 241 is connected to the spreading code selection unit 242 and the interference notification signal generation unit 244.

  The spread code selection unit 242 selects a spread signal to be used by the interference notification signal transmission device 240 from the detected spread code, the detected limit request band, and the limit band requested by the setting recording unit 241 by a method described later.

Spreading section 245 spreads the transmission signal input from interference notification signal generating section 244 using the spreading code selected by spreading code selecting section 242 and outputs the spread signal to radio circuit section 246. The radio circuit unit 246 modulates the transmission signal to a predetermined frequency and transmits it.

  Regarding the code selection and transmission timing, when the interference notification signal transmitted in the surroundings and the band for limiting the new system base station are the same, the same spreading code is selected and the interference notification transmitted in the surroundings is selected. Transmit the signal and timing in synchronization. In this case, individually set fields such as a sender ID may be spread twice. Further, in this case, when there is a limit on the usable spreading codes, when a predetermined number of spreading codes is exceeded, a predetermined common ID and a predetermined spreading code may be used.

  On the other hand, when the interference notification signal transmitted in the surroundings requires the new system base station to use a different band, a different spreading code is selected. Furthermore, the timing at which the amount of transmission of the interference notification signal is expected to be the smallest is found, and the interference notification signal may be transmitted at that timing.

  When selecting a spreading code to be used depending on the usage situation of surrounding spreading codes, unless it is detected that the same spreading code is newly used in the surroundings or unless it is determined that the notification of the interference notification signal has failed, The same spreading code may be used. The fact that the transmission of the interference notification signal has failed (not properly received on the receiving side) is because, for example, a large amount of interference signal is still received after the transmission of the interference signal notification signal. You may guess.

  Further, a predetermined value may be provided for the spreading factor, or may be determined adaptively. For example, a prescribed value is used at the time of initial transmission, but the spreading factor may be increased when the received interference level exceeds the allowable level, and the spreading factor may be reduced when the interference level is lowered.

  In the above, a method for avoiding collision of interference notification signals has been described. However, in practice it is very difficult to completely avoid interference collisions. That is, even if the actual interference notification signal detector can detect the presence of the interference notification signal, the content of the interference notification signal may not be detected normally. For example, the success or failure of reception may be determined by using an error detection code attached to the interference notification signal. An example of a countermeasure for such a situation is to prevent signal transmission from starting for a predetermined period of time. Here, when the interval for transmitting the interference notification signal is determined, for example, the predetermined fixed time may be set to the interval.

  Moreover, the cause of the problem that the content of the interference notification signal cannot be received normally is not necessarily the collision of the interference notification signal, the reception level (reception quality) of the interference notification signal is very low, and the influence of noise In some cases, the determination of the signal is erroneous. In such a case, the new system base station and the existing system receiver are considered to be considerably separated. Therefore, in this case, when the interference notification signal is detected and cannot be normally received, if the reception level of the interference notification signal is equal to or lower than the specified value, it may not be necessary to respond to a request for prohibition of band use. .

  By the way, it is expected that the situation will not be (completely) improved even after the interference notification signal transmitting apparatus transmits the interference notification signal. In an actual communication environment, existing interference notification signals are transmitted due to radio wave propagation conditions, positional relationship of base stations, etc., equipment malfunctions, inappropriate operation at new system base stations, etc. The amount of interference signal received by the system may not (sufficiently) decrease.

  As a countermeasure in such a case, when the interference notification system is duplicated (interference notification systems A and B) and the situation is not completely improved by the interference notification system A, the interference notification system B is used to improve the situation. You may make it show.

  When the interference notification system is duplexed, the content required by one interference notification system A and the content required by the other interference notification system B may be different.

  For example, after the notification by the interference notification system A, the new system base station that receives the notification from the interference notification system B may immediately stop the allocation of the corresponding band and analyze the cause.

  Alternatively, the following processing may be performed.

  The interference notification signal detection unit (or the entire transmission / reception device) of the interference notification system A may be restarted.

  -Notification to a maintenance person or an operator may be performed.

  The ID of the new system base station that is the cause of the interference (interfering source) may be specified and notified together with the ID.

  Furthermore, when the cause that the interference level is not improved is in the uplink, the user apparatus that is the cause (typically a mobile station, but may be a fixed station) may be specified. The operation side grasps the user equipment that frequently causes the problem of inter-system interference, and the new system operator performs appropriate processing such as testing or replacing the user equipment for such user equipment. You may make it perform.

  Regarding the identification of the link (uplink, downlink) and user equipment that cause interference, the interference detection apparatus analyzes the control signal of the new system in addition to the detection of the interference signal, and the frame number, the type of uplink and downlink, It is preferable that identification is possible by grasping the terminal identification number and the like.

  The interference detected by the interference notification system B may be notified to an authority or an organization that intends to appropriately operate the frequency. Furthermore, the notification of interference by the interference notification system B may be not a radio notification but may use a line of another public wireless communication system, or may use a wired telephone communication network or an Internet line.

  Although the present invention has been described above with reference to specific embodiments, each embodiment is merely illustrative, and those skilled in the art will appreciate various variations, modifications, alternatives, substitutions, and the like. Let's go. For example, in a system that transmits interference notification signals in synchronization, a terminal whose transmission timing should be synchronized with other interference notification signals may operate asynchronously. When the interference notification should be performed in accordance with the operation of the existing system receiver, an abnormality such as the continuous transmission of the interference notification signal may be detected to take measures when the abnormality is detected. Furthermore, not only abnormal operations but also terminals that transmit radio waves illegally may be monitored.

  In the above embodiment, a terminal that receives a broadcast signal has been described as an example. However, the present invention may be applied to a hospital or the like when it is desired to restrict communication using a specific frequency due to an influence on an electronic device. Good. In this specification, an example in which the new system is a communication system has been described. However, the new system may be a broadcast system. As for the interference notification signal transmission device, in preparation for renewal of a new system sharing a frequency or a specification change system change, a control unit or the like can receive a program through a wireless or wired line and can update a reception algorithm (so-called SDR is applied) ) You may keep it like this.

  Although specific numerical examples have been described in order to facilitate understanding of the invention, these numerical values are merely examples and any appropriate values may be used unless otherwise specified. The division of each embodiment is not essential to the present invention, and two or more embodiments may be used as necessary. For convenience of explanation, an apparatus according to an embodiment of the present invention has been described using a functional block diagram, but such an apparatus may be realized by hardware, software, or a combination thereof. The present invention is not limited to the above embodiments, and various modifications, modifications, alternatives, substitutions, and the like are included in the present invention without departing from the spirit of the present invention.

  Further, in the claims, the terms “prohibition signal” and “prohibition signal transmitter” are used. These terms correspond to “interference notification signal” and “interference notification signal transmitter” in the specification and drawings, respectively. The terms in the claims should not be interpreted more restrictively than the terms in the specification and drawings.

The system block diagram which can be used by this invention is shown. It is a figure which shows the example of a format of an interference alerting | reporting signal. It is a figure which shows the structure of an interference alerting signal transmission apparatus. It is a figure which shows the structural example of the base station of a new system. It is a figure which shows the structural example of an interference alerting signal detection part. It is a figure which shows the example 1 of a method which synchronizes locally. It is a figure which shows the example 2 of a method which takes synchronization locally. FIG. 6 shows how to use both CSMA and slotting. FIG. 6 shows how to use both CSMA and slotting. It is a figure which shows a mode that the operation condition of a receiver is notified to an interference alert signal transmission apparatus. It is a figure which shows a mode that the operation condition of a receiver is notified to an interference alert signal transmission apparatus. It is a figure which shows a mode that a zone | band is restrict | limited based on the operating state of a receiver. It is a figure which shows a mode that a zone | band is restrict | limited based on the use zone | band of the receiver in operation. It is a figure which shows the interference alerting signal transmission apparatus used in 4th Example. It is a figure which shows the band for new systems, and the band currently used in the existing system. It is a figure which illustrates the positional relationship of an interference alert signal transmission apparatus and a new system base station. FIG. 2 is a diagram illustrating an arrangement of interference notification signal transmission apparatuses A and B and a new system base station C. It is a figure of the interference generation | occurrence | production by the interference alert signal stop of an adjacent interference alert signal transmission apparatus. It is a figure of the method of solving the interference generation | occurrence | production by the interference alert signal stop of an interference alert signal transmission apparatus. It is a figure which shows the apparatus structural example of an interference alerting signal transmission apparatus. It is a figure which shows arrangement | positioning of the new system base stations C and D and the existing system receiver. It is a figure of interference generation at the time of detecting reception of a limit zone information signal and stopping transmission of an interference information signal. It is a figure of the method of avoiding "the situation which suffers temporary interference" by a temporary transmission period. It is a figure which shows the apparatus structural example of an interference alerting signal transmission apparatus.

Explanation of symbols

31, 141, 241 Setting recording unit 32, 142, 244 Interference notification signal generation unit 33, 143, 246 Radio circuit unit 144 Transmission control unit 145 Interference signal reception unit 242 Spreading code selection unit 243 Notification signal reception unit 245 Spreading unit

Claims (32)

A prohibition signal transmitting apparatus used in a complex system in which at least a part of a system band of an old communication system overlaps a system band of a new communication system,
Means for monitoring what band is actually used in communication among the bands allocated to the old communication system;
Means for creating a prohibition signal indicating that the use band should not be used in the new communication system;
Means for notifying the prohibition signal to a communication device of the new communication system;
A prohibition signal transmitting apparatus having   The prohibition signal transmitting apparatus according to claim 1, wherein the use band is monitored based on an operating state of a receiver used in the old communication system.   The prohibition signal transmission device according to claim 2, wherein the use band is monitored by determining an operating state of the receiver based on a reception power of a signal received by the receiver.   The prohibition signal transmission apparatus according to claim 1, further comprising means for measuring an interference amount received by the old communication system from the new communication system in a band other than the use band.   The prohibition signal transmitting apparatus according to claim 4, wherein a spreading factor when code-spreading the prohibition signal is determined according to the amount of interference.   The prohibition signal transmitting apparatus according to claim 4 or 5, wherein transmission power for transmitting the prohibition signal is determined according to the amount of interference.   When a prohibition signal for requesting prohibition of use of a specific band is received from a device different from the prohibition signal transmitting device, a band that should not be used when the specific band and the use band are the same The prohibition signal transmission device according to claim 1, wherein the prohibition signal is inhibited from being transmitted to the communication device.   When a prohibition signal for requesting the prohibition of use of a specific band is received from a device different from the prohibition signal transmitting device, the use prohibition of the use band is determined when the specific band differs from the use band. The prohibition signal transmitting apparatus according to claim 1, wherein the prohibition signal is transmitted to the communication apparatus.   Even if the specific band is the same as the use band, if the reception quality of the prohibit signal indicating the specific band is worse than a predetermined value, the prohibit signal indicating the use band is transmitted to the communication device. The prohibition signal transmitting apparatus according to claim 1. Received from the communication device broadcast information indicating a band reserved for use in the communication device of the new communication system among the bands allocated to the new communication system,
The prohibition signal transmission device according to claim 1, wherein the prohibition signal transmission is suppressed when the use band is included in the band that is refrained from use, which is transmitted by the broadcast information. Received from the communication device broadcast information indicating a band reserved for use in the communication device of the new communication system among the bands allocated to the new communication system,
The prohibition signal transmission device according to claim 1, wherein the prohibition signal is notified to the communication device when the use band is not included in the band that is refrained from use, which is transmitted by the broadcast information.   9. The prohibition signal transmitting apparatus according to claim 8, wherein a spreading code used for the prohibition signal indicating the use band is determined according to whether the specific band and the use band are the same.   2. The prohibition signal transmitting apparatus according to claim 1, wherein the prohibition signal transmitting apparatus is synchronized with another prohibition signal transmitting apparatus having the same function so as to recognize the same slot boundary. The sum of the period of the prohibition signal from the prohibition signal transmitter, the backoff period after the slot boundary preceding the prohibition signal, and the postamble period from the prohibition signal to the next slot boundary is one slot. No period,
14. The prohibition signal transmission device according to claim 13, wherein the prohibition signal transmission device and the other prohibition signal transmission device are set to have different back-off periods.   The transmission timing of the prohibition signal is set so that the preamble in the prohibition signal transmitted from the prohibition signal transmission apparatus and the other preamble in the other prohibition signal from the other prohibition signal transmission apparatus are transmitted simultaneously. The prohibition signal transmitting apparatus according to claim 13. A communication device in a new communication system having a system band that overlaps at least a part of a system band of an old communication system,
Means for receiving, from the old system, a prohibition signal indicating a band that refrains from use in the new communication system among usable bands usable by the new communication system;
After the prohibition signal is no longer received, it is monitored whether the prohibition signal can be received for a predetermined period. If the prohibition signal cannot be received during the predetermined period, the band that is refrained from use is used. Communication device. A communication device in a new communication system having a system band that overlaps at least a part of a system band of an old communication system,
Means for receiving, from the old system, a prohibition signal indicating a band that refrains from use in the new communication system among usable bands usable by the new communication system;
When the prohibition signal is not received, a signal is transmitted during a predetermined provisional transmission period to monitor whether the prohibition signal can be received. When the prohibition signal cannot be received during the provisional transmission period, use is prohibited. A communication device using the band. A base station apparatus used in a new mobile communication system having a system band that overlaps at least a part of a system band of an old communication system,
Scheduling means for scheduling radio resources;
Means for creating a control signal indicating the contents of scheduling;
Means for transmitting the control signal to a mobile station device;
The base station apparatus further includes means for receiving a prohibition signal indicating a use band actually used for communication among bands allocated to the old communication system,
The base station apparatus that performs scheduling so that a band other than the used band among bands allocated to the new mobile communication system is allocated to the mobile station apparatus.   The base station apparatus according to claim 18, wherein a band that is refrained from being used by the base station apparatus among bands allocated to the mobile communication system is notified to the mobile station apparatus.   The base station apparatus according to claim 18, wherein a signal indicating that the prohibition signal should be transmitted is notified to a communication apparatus of an old communication system.   The base station apparatus according to claim 18, wherein the base station apparatus is synchronized with another base station apparatus having the same function so as to recognize the same slot boundary. The sum of the period of the prohibition signal from the base station apparatus, the back-off period after the slot boundary preceding the prohibition signal, and the postamble period from the prohibition signal to the next slot boundary is one slot. ,
The base station apparatus according to claim 21, wherein the base station apparatus and the other base station apparatus are set to have different back-off periods.   The transmission timing of the prohibition signal is set so that the preamble in the prohibition signal transmitted from the base station apparatus and the other preamble in the other prohibition signal from the other base station apparatus are transmitted simultaneously. The base station apparatus according to claim 21. A complex system including a plurality of old and new communication systems in which at least part of a system band overlaps each other,
Means for monitoring what band is actually used in communication among the bands allocated to the old communication system;
Means for notifying the base station apparatus of a prohibition signal indicating that the use band should not be used in the mobile communication system;
The base station device of the new communication system has a prohibition signal transmission device having
Means for receiving the prohibition signal;
Scheduling means for scheduling radio resources so that a band other than the used band among bands allocated to the new communication system is allocated to the mobile station device;
Means for transmitting a control signal indicating the contents of scheduling to the mobile station device;
A composite communication system.   If at least the first and second prohibition signal transmitters exist and the reception quality of the prohibition signal from the first prohibition signal transmitter is less than a predetermined value, the prohibition signal is transmitted from the second prohibition signal transmitter. 25. The composite communication system according to claim 24, wherein is transmitted.   26. The decoding communication system according to claim 25, wherein the second prohibition signal transmitting apparatus transmits a prohibition signal when an amount of interference received from the base station apparatus is a predetermined value or more.   26. The composite communication system according to claim 25, wherein the transmission timing of the prohibition signal transmitted from each of the plurality of old communication systems is adjusted so as not to collide with each other.   28. The composite communication system according to claim 27, wherein a plurality of old communication systems are synchronized with each other so that a certain prohibition signal transmitter recognizes the same slot boundary as another prohibition signal transmitter having the same function. The sum of the period of the prohibition signal from the prohibition signal transmitter, the backoff period after the slot boundary preceding the prohibition signal, and the postamble period from the prohibition signal to the next slot boundary is one slot. No period,
29. The composite communication system according to claim 28, wherein back-off periods are set to be different from each other in the prohibition signal transmitter and the other prohibition signal transmitter.   The transmission timing of the prohibition signal is set so that the preamble in the prohibition signal transmitted from the prohibition signal transmission device and the other preamble in the other prohibition signal from the other prohibition signal transmission device are transmitted simultaneously. 29. A composite communication system as claimed in claim 28. A method used in a prohibition signal transmission apparatus of a composite system in which at least a part of a system band of an old communication system overlaps with a system band of a new communication system,
Monitoring what bandwidth is actually used in communication among the bands allocated to the old communication system; and
Creating a forbidden signal indicating that the use band should not be used in the new communication system;
Notifying the prohibition signal to a communication device of the new communication system;
Having a method. A method used in a base station apparatus of a new mobile communication system having a system band that overlaps at least a part of a system band of an old communication system,
Receiving a prohibition signal indicating a use band actually used for communication among bands allocated to the old communication system;
A scheduling step for scheduling radio resources;
Creating a control signal indicating the contents of scheduling;
Transmitting the control signal to a mobile station device;
And the scheduling step performs scheduling so that a band other than the used band among bands allocated to the new mobile communication system is allocated to the mobile station apparatus.

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