JP4718395B2 - Base station apparatus and antenna pattern control method - Google Patents

Description

  The present invention is characterized in that a service area is divided into a plurality of cells, and a mobile station in the cell and a base station forming the cell share a frequency band allocated to the system by a multiple access method and perform communication. The present invention relates to a cellular mobile communication system.

  In particular, a TDMA that allocates a set of a plurality of narrowband frequency channels for each cell within a frequency band allocated to the system, and adjusts so that channels of the same or adjacent frequencies are allocated only in cells that are separated from each other. -In the case of an FDM cellular mobile communication system or a CDMA cellular mobile communication system in which the frequency band allocated to the system is shared among users of all cells by code division multiple access, the vertical pattern of the base station antenna is narrowed Of beam tilting, or beam directing when the horizontal pattern of the base station antenna is beamed, and area shaping, reducing the same or adjacent frequency interference between cells, and , Tilt angle and azimuth angle for effective use of radio resources Automatic setting, as well as antenna pattern control method for automatically updating, and to the base station apparatus.

  The radio signal transmitted to the space on the ground surface gradually attenuates as the distance from the transmission point increases due to the diffusion of energy accompanying the propagation process, absorption by vegetation, and shielding by terrain and features. The degree of attenuation is expressed as a propagation loss by the ratio between the transmission power at the transmission point and the reception power at the measurement point. In general, it is known that the propagation loss increases from 8 times to 16 times when the propagation distance is doubled in an urban environment. Therefore, there is a physical lower limit to the thermal noise power level of the receiver, and considering whether or not radio signals can be received based on the relative ratio of the received power and the thermal noise power, the upper limit value of the transmission power of the transmitter It can be seen that the receivable distance is limited.

  The cellular mobile communication system is characterized in that a wide service area is divided into cells, which are relatively narrow areas, and a base station installed for each cell is in charge of communication with a mobile station located in the cell. This is because, as described above, the receivable distance of the radio signal is limited by the upper limit value of the transmission power of the transmitter. Therefore, when trying to handle one base station without dividing a wide service area, the device This is because a transmission power value that cannot be realized in the configuration is required. In order to realize the base station apparatus, it is preferable to reduce the cell size (small cell size). On the other hand, the number of cells necessary to cover the service area, that is, the number of base stations to be installed increases.

  In a cellular mobile communication system to which a finite frequency band is allocated, downsizing also has the effect of increasing the system capacity, specifically the number of mobile stations that can be accommodated simultaneously. The capacity of the uplink of code division multiple access (CDMA) is determined by the amount of uplink interference, which is the sum of interference due to the delay wave of the demodulation target channel itself that has arrived at the receiver, interference due to other channels, and receiver thermal noise. . The interference due to other channels includes interference coming from a cell transmitting the demodulation target channel (own cell interference) and interference coming from a cell other than the cell transmitting the demodulation target channel (other cell interference).

  When the cell size is reduced, the mobile station is distributed and accommodated in each cell, so that self-cell interference is reduced. Further, by reducing other cell interference, interference due to other channels is reduced, and uplink capacity is increased. In the downlink, the transmission power of the base station is finite. In a mobile station, if the amount of downlink interference, which is the sum of interference due to a delayed wave of the channel to be demodulated, own cell interference, other cell interference, and receiver thermal noise, is large, in order to maintain the required communication quality, The transmission power of the base station increases. That is, in order to accommodate a large number of mobile stations, it is necessary to reduce the amount of downlink interference, and it is important to reduce interference from other cells.

  Further, in order to reduce interference from other cells, it is important to determine the pattern of the antenna installed in the base station. While a relatively high gain is obtained in the main lobe direction of the antenna pattern, the gain in the side lobe direction is kept relatively low. Therefore, the other cell interference can be reduced by directing the main lobe of the antenna pattern toward the own cell and the side lobe toward the other cell. Here, directing the main lobe of the antenna vertical pattern to the own cell and directing the side lobe to other cells is called beam tilting, and the main lobe of the antenna horizontal pattern is directed to the own cell and the side lobe is directed to the other cell. This is called beam directing.

  Beam tilting (beam directing) that maximizes system capacity in the assigned frequency band is set by an appropriate half-width and tilt angle (azimuth angle). Here, the half width is an angle (main lobe width) formed by a direction in which the gain is within 3 dB with respect to the maximum gain of the vertical (horizontal) pattern, and indicates the degree of narrowing of the beam. Also, the tilt angle is the angle between the maximum gain direction of the vertical pattern and the horizontal direction, and becomes a positive number when the maximum gain direction is directed toward the ground side, and the azimuth angle is the maximum gain direction of the horizontal pattern and the true north direction. It is an angle to make. When the cell arrangement, that is, the cell edge (cell boundary) is fixed in advance by design, the following can be said qualitatively about optimum beam tilting.

  In a base station that forms a cell with a small cell radius (distance between the base station and the cell edge), when the half-width of the vertical pattern of the antenna is small, sufficient antenna gain is ensured in the main lobe direction (usually the cell edge). Since the side lobe is directed in the direction where the expected angle is larger than the main lobe direction, it becomes impossible to secure the necessary antenna gain in the cell.

  On the other hand, if the vertical pattern half-width of the antenna is large in a base station that forms a cell with a large cell radius, sufficient antenna gain is secured in the cell, but it is necessary in the main lobe direction (usually the cell edge). A large antenna gain cannot be secured.

  In addition, if the tilt angle of the antenna vertical pattern is small in the base station, the antenna gain increases with respect to the area (other cells) other than the area that the base station is responsible for because the directing direction of the main lobe approaches horizontal. At the same time as the interference to be given increases, the interference from mobile stations located in other cells also increases.

  On the contrary, if the tilt angle of the antenna vertical pattern is large in the base station, the directivity direction of the main lobe approaches vertical, so that the antenna gain to the cell edge decreases and deterioration due to thermal noise (coverage loss) occurs. These relationships are shown in Non-Patent Document 1.

  In addition, an appropriate base station antenna type (beam tilting, beam directing) is manually designed by simulating and calculating the radio wave propagation state between each point and each base station using a cell design system using an electronic map. A method is shown in Non-Patent Document 2.

  Non-Patent Document 3 discloses a specific method for manually designing an appropriate beam tilting based on data obtained by measuring each point in an actual service area using a measuring device. In Non-Patent Document 3, a radio wave propagation state estimation simulation is possible based on actual measurement values when only the tilt angle is changed without changing the half width, and the cell designer cuts and tilts the tilt angle. Adjust to. By doing so, it is possible to improve the reception level degradation in the service area, increase the tolerance to interference from neighboring cells using the same frequency band or adjacent frequency band, and to design an appropriate tilt angle manually. it can.

  Further, Patent Document 1 appropriately sets an appropriate tilt angle and vertical pattern half-value width that are manually designed in advance for each state based on at least one of the state of the service area and the instruction from the outside. A method of appropriately controlling communication quality and system capacity by automatic selection or instruction selection is disclosed.

  Specifically, the traffic volume is monitored as a service area state, and when the traffic volume is in a full load state, base station antennas that supply transmission signals are vertically stacked by placing them at regular intervals. By reducing the number of radiating elements, the half width of the vertical pattern is widened, and at the same time, the tilt angle is increased by setting the difference in phase shift amount between adjacent radiating elements to the maximum value.

  Alternatively, as the amount of traffic decreases, the vertical pattern half-value width is narrowed by gradually increasing the number of vertically stacked radiating elements of the base station antenna that supplies the transmission signal, and at the same time, the amount of phase shift between adjacent radiating elements is reduced. The tilt angle is reduced by gradually reducing the difference. Here, the optimum tilt angle and vertical pattern half-value width corresponding to each service area state are designed manually by the cell designer in advance so that they can be appropriately selected. As a result, a vertical pattern is formed to ensure a large system capacity in a cell with a smaller cell radius and a smaller coverage as the traffic volume increases, and a smaller system capacity is secured in a cell with a larger cell radius and wider coverage as the traffic volume decreases. Thus, a vertical pattern is formed. In this way, it is possible to improve the system capacity and coverage as a whole following changes in the service area.

  In addition, the tilt angle of the vertical pattern and the azimuth angle of the horizontal pattern in the base station antenna for reducing the same and adjacent frequency interference between cells and effectively using radio resources can be set regardless of the cell designer's manual design. There is a method of automatically generating and automatically updating following a change in the state of the service area.

  Specifically, the mobile station reports the reception level of the common pilot channel associated with the transmission base station measured at the time of handover as a monitor set to the handover source base station. The monitor set is a set of base stations in a cell that is a candidate for a handover destination for which the mobile station has measured the reception level.

The base station calculates the degree of adjacency of neighboring cells from the reported monitor set, that is, the degree of sharing of electromagnetic space between the neighboring cells. Based on the degree of adjacency, beam tilting and beam directing of the own base station and neighboring base stations are optimally set.
Hayashi, Mori et al., 2003 Shingaku Sodai B-5-35, “Optimization of base station antenna vertical half-value angle and tilt angle in cellular mobile communications”, March 2003. Fujii, Asakura et al., NTT DoCoMo Technical Journal Vol. 2 No. 4. “Cell design system for mobile communications”, January 1995. Asakura, Fujii et al., IEICE Technical Report RCS95-130, “Mobile Communication Cell Design System Using Real Propagation Data”, January 1996. JP 2005-109690 A

  However, the background art described above has the following problems.

  The mainstream macro cells (area radius of 10 km or less) and micro cells (area radius of 3 km or less), such as street micro cells (area radius of 1 km or less) and pico cells (area radius of 0.5 km or less), which are expected to become mainstream in the future. ) In a cell with a smaller area than that of), estimation calculation is performed by simulating the radio wave propagation state between each point and each base station as shown in the above conventional method, or a point in the actual service area is measured by a measuring device. It is more difficult to manually design appropriate beam tilting and beam directing by measuring the received power every time. This is explained as follows.

  In conventional macro and micro cells, antennas are installed at high positions such as towers, high-rise buildings, and the tops of mountains, so that a wide cell coverage is formed and the propagation distance to the cell edge is relatively long. The influence of individual buildings is statistically averaged for each direction seen from Therefore, it was possible to form an area close to a hexagon centered on a base station in which the area ends are smoothly continuous.

  For this reason, it is possible to accurately estimate the propagation loss in the cell by using the propagation estimation formula defined for each rough city structure, while receiving support from the cell design system that takes into account the rough city structure using the electronic map. In addition, it was possible to design appropriate beam tilting and beam directing by simulating and calculating the radio wave propagation state between each point and each base station.

  The macro / micro cell has a larger area radius than the street micro cell and pico cell described above, so the influence of individual buildings is statistically averaged, and all service areas (roads, plazas, etc.) in the area are averaged. Even if it was not actually measured with a measuring device, representative data could be obtained by roughly measuring a part of it, and based on this, appropriate beam tilting and beam directing could be designed.

  On the other hand, in a street micro cell or a pico cell, a narrow cell coverage is formed by installing an antenna at a position lower than a building around a base station, and a propagation distance to an area edge is relatively short. From this, it is easy to be influenced by individual buildings and features for each azimuth viewed from the base station, and a cell having a complex shape (amoeba shape) is formed with discontinuous area edges. For this reason, it is difficult to accurately estimate the state of radio wave propagation in the area using the propagation estimation formula defined for each rough urban structure, and beam tilting and beam directing can be performed accurately using conventional cell design systems. It becomes difficult to design.

  In the cell design system that estimates the propagation loss by the ray tracing method, it is possible to consider individual buildings and features when estimating the radio wave propagation state by allowing a large amount of calculation. However, the electronic map cannot fully describe the real environment such as the detailed shape of the building, and since the real environment changes with time, the information on the electronic map is not real-time, so the estimation accuracy is sufficient It can not be said.

  In addition, in the method of designing the tilt angle by actual measurement using a measuring device, appropriate beam tilting is required unless the actual measurement of the majority of the service area (roads, plazas, etc.) due to the complicated shape of the area. And beam directing cannot be designed. Furthermore, the number of base stations to be installed increases dramatically with the downsizing of the cell, which may greatly complicate the cell design work.

  Patent Document 1 automatically selects an appropriate tilt angle and vertical pattern half-value width that are manually designed in advance for each state based on at least one of the state of the service area and the instruction from the outside. Alternatively, a method for appropriately controlling communication quality and system capacity by selecting an instruction is disclosed. However, the optimum tilt angle and vertical pattern half-value width corresponding to each service area state must be designed manually in advance by the cell designer so that they can be selected as appropriate.

  In addition, the tilt angle in beam tilting at the base station and the azimuth angle in beam directing are automatically generated regardless of the cell designer's manual design, and automatically updated following the service area state change. In this case, since the degree of adjacency with the next adjacent cell (cell adjacent to the adjacent cell) is controlled within a certain range, interference with the adjacent cell and interference from the adjacent cell cannot be effectively reduced. .

  Therefore, an object of the present invention is to provide a base station apparatus and an antenna pattern control method for automatically setting an antenna pattern that can effectively reduce interference from other cells and automatically updating the antenna pattern following a change in the service area state. To do.

This based on Chikyoku device,
A base station apparatus in a cellular mobile communication system comprising:
Based on the statistics of the usage of radio resources including the uplink interference amount and the total transmit power observed in the base station apparatus, a radio resource use status determining means for determining the usage of radio resources in the base station apparatus;
Antenna pattern control means for designating an antenna pattern on the basis of the radio resource usage status determined by the radio resource usage status determination means;
An antenna that emits radio waves with an antenna pattern specified by the antenna pattern control means;
Equipped with a,
The radio resource usage status determining unit determines that the radio resource usage status of the base station apparatus is “tight” when the statistical value of the uplink interference amount in the base station apparatus for a certain period is equal to or greater than a first specified value. When the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and the second prescribed value. If it is above, it is judged as “appropriate”,
When the antenna pattern control means designates the depression angle of the main lobe of the antenna vertical pattern based on the determination result of the radio resource usage status by the radio resource usage status determination means, the radio resource usage status of the base station apparatus Is “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is increased, and when the usage status of the radio resource of the base station apparatus is “surplus”, the antenna vertical direction of the base station apparatus When the depression angle of the main lobe of the pattern is reduced and the usage status of the radio resource of the base station apparatus is “appropriate”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus is not updated, As the radio resource and the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus after updating for a certain period using the uplink interference amount of the base station apparatus Comparing the main lobe angle of the antenna vertical pattern of the base station apparatus after updating for a certain period using the total transmission power of the base station apparatus, the larger angle of depression is determined as the antenna vertical angle of the base station apparatus. Set to the depression angle of the pattern.
This base station device
A base station apparatus in a cellular mobile communication system comprising:
Radio resource usage status determining means for determining radio resource usage status in the base station apparatus based on statistics of radio resource usage including the amount of uplink interference and total transmission power observed in the base station apparatus;
Antenna pattern control means for designating an antenna pattern on the basis of the radio resource usage status determined by the radio resource usage status determination means;
An antenna that emits radio waves with an antenna pattern specified by the antenna pattern control means;
With
The radio resource usage status determining unit determines that the radio resource usage status of the base station apparatus is “tight” when the statistical value of the uplink interference amount in the base station apparatus for a certain period is equal to or greater than a first specified value. When the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and the second prescribed value. If it is above, it is judged as “appropriate”,
When the antenna pattern control means designates the depression angle of the main lobe of the antenna vertical pattern based on the determination result of the radio resource usage status by the radio resource usage status determination means, the radio resource usage status of the base station apparatus Is “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is increased, and when the usage status of the radio resource of the base station apparatus is “surplus”, the antenna vertical direction of the base station apparatus When the depression angle of the main lobe of the pattern is reduced and the usage status of the radio resource of the base station apparatus is “appropriate”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus is not updated, The depression angle of the main lobe of the antenna vertical pattern of the base station apparatus after updating for a certain period using the uplink interference amount of the base station apparatus is equal to or greater than a predetermined specified value In some cases, the depression angle is set to the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus, and when the depression angle is less than the specified value, the total transmission power of the base station apparatus is used as a radio resource for a certain period of time. After the update, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus is set to the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus.
This base station device
A base station apparatus in a cellular mobile communication system comprising:
Radio resource usage status determining means for determining radio resource usage status in the base station apparatus based on statistics of radio resource usage including the amount of uplink interference and total transmission power observed in the base station apparatus;
Antenna pattern control means for designating an antenna pattern on the basis of the radio resource usage status determined by the radio resource usage status determination means;
An antenna that emits radio waves with an antenna pattern specified by the antenna pattern control means;
With
The radio resource usage status determining unit determines that the radio resource usage status of the base station apparatus is “tight” when the statistical value of the uplink interference amount in the base station apparatus for a certain period is equal to or greater than a first specified value. When the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and the second prescribed value. If it is above, it is judged as “appropriate”,
The antenna pattern control means uses the uplink interference amount of the base station apparatus when designating the depression angle of the main lobe of the antenna vertical pattern based on the determination result of the radio resource usage status by the radio resource usage status determination means. If at least one of the usage status of the radio resource determined in step S1 and the usage status of the radio resource determined using the total transmission power of the base station device is "tight", the main lobe of the antenna vertical pattern of the base station device Both the usage status of the radio resource determined using the uplink interference amount of the base station device and the usage status of the radio resource determined using the total transmission power of the base station device are “surplus”. The base station apparatus antenna vertical pattern main lobe depression angle is reduced, and the radio resource usage status determined using the uplink interference amount of the base station apparatus and If at least one of the usage statuses of the radio resources determined using the total transmission power of the base station apparatus is “appropriate” and the other is not “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is Do not update.
This base station device
A base station apparatus in a cellular mobile communication system comprising:
Radio resource usage status determining means for determining radio resource usage status in the base station apparatus based on statistics of radio resource usage including the amount of uplink interference and total transmission power observed in the base station apparatus;
Antenna pattern control means for designating an antenna pattern on the basis of the radio resource usage status determined by the radio resource usage status determination means;
An antenna that emits radio waves with an antenna pattern specified by the antenna pattern control means;
With
The radio resource usage status determining means determines that the radio resource usage status of the base station apparatus is “tight” when a statistical value of the total transmission power in the base station apparatus for a certain period is equal to or greater than a first specified value. When the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and greater than or equal to the second prescribed value. If it is
When the antenna pattern control means designates the depression angle of the main lobe of the antenna vertical pattern based on the determination result of the radio resource usage status by the radio resource usage status determination means, the radio resource usage status of the base station apparatus Is “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is increased, and when the usage status of the radio resource of the base station apparatus is “surplus”, the antenna vertical direction of the base station apparatus When the depression angle of the main lobe of the pattern is reduced and the usage status of the radio resource of the base station apparatus is “appropriate”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus is not updated, As the radio resource and the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus after updating for a certain period using the uplink interference amount of the base station apparatus Comparing the main lobe angle of the antenna vertical pattern of the base station apparatus after updating for a certain period using the total transmission power of the base station apparatus, the larger angle of depression is determined as the antenna vertical angle of the base station apparatus. Set to the depression angle of the pattern.
This base station device
A base station apparatus in a cellular mobile communication system comprising:
Radio resource usage status determining means for determining radio resource usage status in the base station apparatus based on statistics of radio resource usage including the amount of uplink interference and total transmission power observed in the base station apparatus;
Antenna pattern control means for designating an antenna pattern on the basis of the radio resource usage status determined by the radio resource usage status determination means;
An antenna that emits radio waves with an antenna pattern specified by the antenna pattern control means;
With
The radio resource usage status determining means determines that the radio resource usage status of the base station apparatus is “tight” when a statistical value of the total transmission power in the base station apparatus for a certain period is equal to or greater than a first specified value. When the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and greater than or equal to the second prescribed value. If it is
When the antenna pattern control means designates the depression angle of the main lobe of the antenna vertical pattern based on the determination result of the radio resource usage status by the radio resource usage status determination means, the radio resource usage status of the base station apparatus Is “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is increased, and when the usage status of the radio resource of the base station apparatus is “surplus”, the antenna vertical direction of the base station apparatus When the depression angle of the main lobe of the pattern is reduced and the usage status of the radio resource of the base station apparatus is “appropriate”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus is not updated, The depression angle of the main lobe of the antenna vertical pattern of the base station apparatus after updating for a certain period using the uplink interference amount of the base station apparatus is equal to or greater than a predetermined specified value In some cases, the depression angle is set to the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus, and when the depression angle is less than the specified value, the total transmission power of the base station apparatus is used as a radio resource for a certain period of time. After the update, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus is set to the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus.
This base station device
A base station apparatus in a cellular mobile communication system comprising:
Radio resource usage status determining means for determining radio resource usage status in the base station apparatus based on statistics of radio resource usage including the amount of uplink interference and total transmission power observed in the base station apparatus;
Antenna pattern control means for designating an antenna pattern on the basis of the radio resource usage status determined by the radio resource usage status determination means;
An antenna that emits radio waves with an antenna pattern specified by the antenna pattern control means;
With
The radio resource usage status determining means determines that the radio resource usage status of the base station apparatus is “tight” when a statistical value of the total transmission power in the base station apparatus for a certain period is equal to or greater than a first specified value. When the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and greater than or equal to the second prescribed value. If it is
The antenna pattern control means uses the uplink interference amount of the base station apparatus when designating the depression angle of the main lobe of the antenna vertical pattern based on the determination result of the radio resource usage status by the radio resource usage status determination means. If at least one of the usage status of the radio resource determined in step S1 and the usage status of the radio resource determined using the total transmission power of the base station device is "tight", the main lobe of the antenna vertical pattern of the base station device Both the usage status of the radio resource determined using the uplink interference amount of the base station device and the usage status of the radio resource determined using the total transmission power of the base station device are “surplus”. The base station apparatus antenna vertical pattern main lobe depression angle is reduced, and the radio resource usage status determined using the uplink interference amount of the base station apparatus and If at least one of the usage statuses of the radio resources determined using the total transmission power of the base station apparatus is “appropriate” and the other is not “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is Do not update.

  By adopting such a configuration, the antenna pattern is controlled so that the use state of the radio resources of the base station becomes appropriate, so that it comes from other cell interference, that is, a cell other than the cell communicating with the demodulation target channel. The coverage area of the base station can be set to an appropriate range while effectively reducing the interference by the channel.

This antenna pattern control method is
An antenna pattern control method in a base station apparatus in a cellular mobile communication system comprising:
The step of observing the amount of radio resources including the uplink interference amount and the total transmission power in the base station apparatus;
Based on the amount of radio resources that have been observed by the step of said monitoring, calculating a predetermined statistics;
Determining the usage status of the radio resource from the statistical value of the radio resource usage;
Specifying antenna patterns based on radio resource usage;
Emitting radio waves with the antenna pattern designated by the step of designating the antenna pattern;
I have a,
In the determining step, when the statistical value of the uplink interference amount in the base station apparatus in a certain period is equal to or more than a first specified value, the usage status of the radio resource of the base station apparatus is determined as “tight”, If the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and greater than or equal to the second prescribed value. If it is determined to be “appropriate”,
In the step of designating the antenna pattern, when the depression angle of the main lobe of the antenna vertical pattern is designated based on the determination result of the radio resource usage status in the determining step, the radio resource usage status of the base station apparatus Is “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is increased, and when the usage status of the radio resource of the base station apparatus is “surplus”, the antenna vertical direction of the base station apparatus When the depression angle of the main lobe of the pattern is reduced and the usage status of the radio resource of the base station apparatus is “appropriate”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus is not updated, The angle of the main lobe of the antenna vertical pattern of the base station apparatus and the radio resource after updating for a certain period using the uplink interference amount of the base station apparatus Then, comparing the main lobe angle of the antenna vertical pattern of the base station apparatus after updating for a certain period using the total transmission power of the base station apparatus, the larger depression angle of the base station apparatus Set the vertical angle of the antenna vertical pattern.
This antenna pattern control method is
An antenna pattern control method in a base station apparatus in a cellular mobile communication system comprising:
Observing the usage of radio resources including uplink interference and total transmission power in the base station apparatus;
Calculating a predetermined statistical value based on the radio resource usage observed in the observing step;
Determining the usage status of the radio resource from the statistical value of the radio resource usage;
Specifying antenna patterns based on radio resource usage;
Emitting radio waves with the antenna pattern designated by the step of designating the antenna pattern;
Have
In the determining step, when the statistical value of the uplink interference amount in the base station apparatus in a certain period is equal to or more than a first specified value, the usage status of the radio resource of the base station apparatus is determined as “tight”, If the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and greater than or equal to the second prescribed value. If it is determined to be “appropriate”,
In the step of designating the antenna pattern, when the depression angle of the main lobe of the antenna vertical pattern is designated based on the determination result of the radio resource usage status in the determining step, the radio resource usage status of the base station apparatus Is “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is increased, and when the usage status of the radio resource of the base station apparatus is “surplus”, the antenna vertical direction of the base station apparatus When the depression angle of the main lobe of the pattern is reduced and the usage status of the radio resource of the base station apparatus is “appropriate”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus is not updated, The angle of inclination of the main lobe of the antenna vertical pattern of the base station apparatus after updating for a certain period using the uplink interference amount of the base station apparatus is a predetermined regulation In the case of the above, the depression angle is set to the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus, and when the depression angle is less than the specified value, the total transmission power of the base station apparatus is used as a radio resource. The depression angle of the main lobe of the antenna vertical pattern of the base station apparatus after updating for a certain period is set to the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus.
This antenna pattern control method is
An antenna pattern control method in a base station apparatus in a cellular mobile communication system comprising:
Observing the usage of radio resources including uplink interference and total transmission power in the base station apparatus;
Calculating a predetermined statistical value based on the radio resource usage observed in the observing step;
Determining the usage status of the radio resource from the statistical value of the radio resource usage;
Specifying antenna patterns based on radio resource usage;
Emitting radio waves with the antenna pattern designated by the step of designating the antenna pattern;
Have
In the determining step, when the statistical value of the uplink interference amount in the base station apparatus in a certain period is equal to or more than a first specified value, the usage status of the radio resource of the base station apparatus is determined as “tight”, If the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and greater than or equal to the second prescribed value. If it is determined to be “appropriate”,
In the step of designating the antenna pattern, the uplink interference amount of the base station apparatus is used when designating the depression angle of the main lobe of the antenna vertical pattern based on the determination result of the radio resource usage status in the determining step. If at least one of the usage status of the radio resource determined in step S1 and the usage status of the radio resource determined using the total transmission power of the base station device is "tight", the main lobe of the antenna vertical pattern of the base station device Both the usage status of the radio resource determined using the uplink interference amount of the base station device and the usage status of the radio resource determined using the total transmission power of the base station device are “surplus”. In this case, the usage state of the radio resource determined by reducing the angle of depression of the main lobe of the antenna vertical pattern of the base station apparatus and using the uplink interference amount of the base station apparatus And when at least one of the usage statuses of the radio resources determined using the total transmission power of the base station apparatus is “appropriate” and the other is not “tight”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus Do not update.
This antenna pattern control method is
An antenna pattern control method in a base station apparatus in a cellular mobile communication system comprising:
Observing the usage of radio resources including uplink interference and total transmission power in the base station apparatus;
Calculating a predetermined statistical value based on the radio resource usage observed in the observing step;
Determining the usage status of the radio resource from the statistical value of the radio resource usage;
Specifying antenna patterns based on radio resource usage;
Emitting radio waves with the antenna pattern designated by the step of designating the antenna pattern;
Have
In the determining step, when the statistical value in a certain period of the total transmission power in the base station apparatus is greater than or equal to a first specified value, the usage status of the radio resource of the base station apparatus is determined as “tight”, When the statistical value is less than the first specified value and less than the second specified value, it is determined as “surplus”, and the statistical value is less than the first specified value and greater than or equal to the second specified value. Is determined to be “appropriate”
In the step of designating the antenna pattern, when the depression angle of the main lobe of the antenna vertical pattern is designated based on the determination result of the radio resource usage status in the determining step, the radio resource usage status of the base station apparatus Is “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is increased, and when the usage status of the radio resource of the base station apparatus is “surplus”, the antenna vertical direction of the base station apparatus When the depression angle of the main lobe of the pattern is reduced and the usage status of the radio resource of the base station apparatus is “appropriate”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus is not updated, The angle of the main lobe of the antenna vertical pattern of the base station apparatus and the radio resource after updating for a certain period using the uplink interference amount of the base station apparatus Then, comparing the main lobe angle of the antenna vertical pattern of the base station apparatus after updating for a certain period using the total transmission power of the base station apparatus, the larger depression angle of the base station apparatus Set the vertical angle of the antenna vertical pattern.
This antenna pattern control method is
An antenna pattern control method in a base station apparatus in a cellular mobile communication system comprising:
Observing the usage of radio resources including uplink interference and total transmission power in the base station apparatus;
Calculating a predetermined statistical value based on the radio resource usage observed in the observing step;
Determining the usage status of the radio resource from the statistical value of the radio resource usage;
Specifying antenna patterns based on radio resource usage;
Emitting radio waves with the antenna pattern designated by the step of designating the antenna pattern;
Have
In the determining step, when the statistical value in a certain period of the total transmission power in the base station apparatus is greater than or equal to a first specified value, the usage status of the radio resource of the base station apparatus is determined as “tight”, When the statistical value is less than the first specified value and less than the second specified value, it is determined as “surplus”, and the statistical value is less than the first specified value and greater than or equal to the second specified value. Is determined to be “appropriate”
In the step of designating the antenna pattern, when the depression angle of the main lobe of the antenna vertical pattern is designated based on the determination result of the radio resource usage status in the determining step, the radio resource usage status of the base station apparatus Is “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is increased, and when the usage status of the radio resource of the base station apparatus is “surplus”, the antenna vertical direction of the base station apparatus When the depression angle of the main lobe of the pattern is reduced and the usage status of the radio resource of the base station apparatus is “appropriate”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus is not updated, The angle of inclination of the main lobe of the antenna vertical pattern of the base station apparatus after updating for a certain period using the uplink interference amount of the base station apparatus is a predetermined regulation In the case of the above, the depression angle is set to the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus, and when the depression angle is less than the specified value, the total transmission power of the base station apparatus is used as a radio resource. The depression angle of the main lobe of the antenna vertical pattern of the base station apparatus after updating for a certain period is set to the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus.
This antenna pattern control method is
An antenna pattern control method in a base station apparatus in a cellular mobile communication system comprising:
Observing the usage of radio resources including uplink interference and total transmission power in the base station apparatus;
Calculating a predetermined statistical value based on the radio resource usage observed in the observing step;
Determining the usage status of the radio resource from the statistical value of the radio resource usage;
Specifying antenna patterns based on radio resource usage;
Emitting radio waves with the antenna pattern designated by the step of designating the antenna pattern;
Have
In the determining step, when the statistical value in a certain period of the total transmission power in the base station apparatus is greater than or equal to a first specified value, the usage status of the radio resource of the base station apparatus is determined as “tight”, When the statistical value is less than the first specified value and less than the second specified value, it is determined as “surplus”, and the statistical value is less than the first specified value and greater than or equal to the second specified value. Is determined to be “appropriate”
In the step of designating the antenna pattern, the uplink interference amount of the base station apparatus is used when designating the depression angle of the main lobe of the antenna vertical pattern based on the determination result of the radio resource usage status in the determining step. If at least one of the usage status of the radio resource determined in step S1 and the usage status of the radio resource determined using the total transmission power of the base station device is "tight", the main lobe of the antenna vertical pattern of the base station device Both the usage status of the radio resource determined using the uplink interference amount of the base station device and the usage status of the radio resource determined using the total transmission power of the base station device are “surplus”. In this case, the usage state of the radio resource determined by reducing the angle of depression of the main lobe of the antenna vertical pattern of the base station apparatus and using the uplink interference amount of the base station apparatus And when at least one of the usage statuses of the radio resources determined using the total transmission power of the base station apparatus is “appropriate” and the other is not “tight”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus Do not update.

  By adopting such a control method, the antenna pattern is controlled so that the radio resource usage of the base station becomes appropriate, so that the coverage area of the base station is appropriately reduced while effectively reducing interference from other cells. Range.

  According to the embodiment of the present invention, it is possible to realize a base station apparatus and an antenna pattern control method that automatically set an antenna pattern that can effectively reduce interference of other cells and automatically update following the service area state change. ,

Next, the best mode for carrying out the present invention will be described based on the following embodiments with reference to the drawings.
In all the drawings for explaining the embodiments, the same reference numerals are used for those having the same function, and repeated explanation is omitted.

  A base station in a radio communication system to which a base station apparatus and an antenna pattern control method according to an embodiment of the present invention are applied will be described with reference to the drawings.

  As a wireless communication system, a set of a plurality of narrowband frequency channels is assigned to each cell within a frequency band assigned to the system, and channels of the same or adjacent frequencies are assigned only to cells arranged separately. A TDMA-FDM cellular mobile communication system that adjusts to CDMA and a CDMA cellular mobile communication system that shares the frequency band assigned to the system among users of all cells by code division multiple access are applied.

  First, the configuration of the base station according to the present embodiment will be described. FIG. 1 is a configuration diagram of the base station according to the present embodiment.

  The base station 100 according to the present embodiment includes a radio resource usage status determination unit 102, an antenna pattern control unit 104, and an antenna 106.

  The base station apparatus 100 automatically sets an antenna pattern in order to reduce interference between the frequency assigned to the own cell and the frequency assigned to the adjacent cell and effectively use radio resources. Specifically, beam tilting when the vertical pattern of the base station antenna is narrowed, beam directing when the horizontal pattern of the base station antenna is beamed, and area shaping are performed. A set consisting of a plurality of narrowband frequency channels is assigned to each cell. Specifically, channels of the same or adjacent frequencies are allocated only in cells arranged in isolation. By doing so, the same or adjacent frequency interference between cells is reduced, and radio resources are effectively used.

  The radio resource usage status determination unit 102 observes, for example, radio resource usage, such as uplink interference, that is, uplink interference and total transmission power, for a certain period of time, for example, average value, median, variance, Calculate its statistical values, such as standard deviation. The uplink interference amount is indicated, for example, by the sum of receiver thermal noise.

  As shown in FIG. 2, when the statistical value of the radio resource usage amount for a certain period is equal to or greater than the first specified value, the usage status of the radio resource of the own station is determined as “tight”. When the statistical value is less than the first specified value and less than the second specified value, it is determined as “surplus”. If the statistical value is less than the first specified value and greater than or equal to the second specified value, it is determined as “appropriate”.

  The reason for such determination will be described in the case where the uplink interference amount or the total transmission power is used as the radio resource usage.

  The first specified value is set to a value 1 dB to 5 dB lower than the call admission control threshold value specified in the CDMA cellular system. Here, the call admission control threshold is a threshold used in call admission control for preventing the cell radius from being reduced. Specifically, when the amount of uplink interference or the total transmission power exceeds this threshold, acceptance of a new channel is rejected.

  The second specified value is set to a value 2 dB to 7 dB lower than the call admission control threshold. That is, it is set to a value 1 dB to 2 dB lower than the first specified value.

  If the statistical value of the amount of uplink interference or the total transmission power is less than the second specified value, the radio resource is surplus and the user can be accommodated.

  Also, when the amount of uplink interference from a mobile station located in another cell that cannot be rejected by call admission control, that is, a cell other than the cell transmitting the demodulation target channel, is large, the uplink interference amount is close to the call admission control threshold value. become. In this way, when the uplink interference amount is equal to or greater than the first specified value, the other cell interference is in a large state, and thus the radio resource usage status is determined to be “tight”. With respect to the total transmission power, if the interference from other cells is large, a large transmission power is required for the mobile station at the cell edge. Furthermore, since the large transmission power to the mobile station at the cell edge causes interference in other mobile stations, a large transmission power is required for other mobile stations. Thus, when the total transmission power is a value close to the call admission control, the other-cell interference is in a large state, and thus the radio resource usage status is determined to be “tight”. If the wireless usage status is neither “surplus” nor “tight”, it is determined as “appropriate”.

  The radio resource usage status determination unit 102 calculates the statistical value of the usage amount of the radio resource observed in the own base station apparatus, and determines the determination result determined based on the calculation result of the statistical value of the radio resource usage amount. Input to the antenna pattern control unit 104.

  The antenna pattern control unit 104 receives the determination result of the radio resource usage status from the radio resource usage status determination unit 102, and determines the antenna pattern based on the result. FIG. 3 shows a method of updating the tilt angle of the antenna vertical pattern of the own base station according to the determination result of the radio resource usage status of the own base station. Here, the tilt angle is an angle formed between the maximum gain direction of the vertical pattern and the horizontal direction as described above, and becomes a positive number when the maximum gain direction is directed to the ground side.

  If the determination result of the radio resource usage status is “tight”, the antenna pattern control unit 104 increases the tilt angle. If the radio resource usage status is “appropriate”, the antenna pattern control unit 104 does not update the tilt angle. If the radio resource usage status is “surplus”, the antenna pattern control unit 104 decreases the tilt angle.

  The reason for controlling the tilt angle in this way will be described in the case where the uplink interference amount or the total transmission power is used as the radio resource usage.

FIG. 4 shows that the amount of accommodated traffic can be increased by reducing the tilt angle when the amount of uplink interference or the usage status of the total transmission power is “surplus”. Since when usage of the uplink interference amount or the total transmission power of the base station 100 ₀ is "surplus" may reserve capacity to accommodate the upstream traffic, to enlarge the charge area to reduce the tilt angle. Thus, it is possible to accommodate the mobile station 108 ₁ has not been accommodated ever, the system capacity increases.

5, by increasing the tilt angle when the usage of uplink interference level of the base station 100 ₀ is "tight", indicating that can reduce the interference from other cells. When the usage state of the uplink interference amount is “tight”, the interference with other cells is large, so the tilt angle is increased to reduce the interference area. As a result, other cell interference can be reduced, and the system capacity can be increased.

FIG. 6 shows that the interference of other cells can be reduced by increasing the tilt angle when the usage status of the total transmission power is “tight”. When the usage status of the total transmission power is “tight”, interference from other cells is large, so the tilt angle is increased to reduce the cover area. Thus, the mobile station 108 ₂ that had suffered large interference from the base station 100 ₁ is handed over to the base station 100 _1. As a result, interference from other cells is reduced, and the system capacity increases.

  Which of the usage status of the uplink interference amount and the usage status of the total transmission power can be achieved as a determination result depends on the total transmission power, cell radius, and traffic distribution of the base station 100. For example, when the total transmission power of the base station 100 is large or the cell radius is small, the uplink interference amount is higher than the total transmission power, as in the case where the uplink traffic is larger than the downlink traffic. In a situation where there is a high possibility of being tight, it is better to use the usage status of the uplink interference amount as a determination result.

  On the other hand, for example, when the total transmission power of the base station is small or the cell radius is large, the total transmission power is larger than the amount of uplink interference as in the case where the downlink traffic is larger than the uplink traffic. In a situation where there is a high possibility that the user will be more strained, it is better to use the usage status of the total transmission power as a determination result.

  A case will be described in which it is impossible to predict in advance which of the uplink interference amount and the total transmission power is more likely to be tight because the cell radius and traffic distribution cannot be predicted.

  As shown in FIG. 7, in this case, the tilt of the antenna vertical pattern of the own base station is determined according to the judgment result of the usage status of the uplink interference amount of the own base station and the judgment result of the usage status of the total transmission power of the own base station. Update corners.

  If at least one of the usage status of the uplink interference amount and the usage status of the total transmission power is “tight”, the tilt angle is increased. If both the usage status of the uplink interference amount and the usage status of the total transmission power are “surplus”, the tilt angle is decreased. If at least one of the usage status of the uplink interference amount and the usage status of the total transmission power is “appropriate” and the other is “tight”, the tilt angle is not updated.

  As described above, the system capacity can be improved in any cell radius and traffic distribution by performing control giving priority to the more constrained of the uplink interference amount and the total transmission power.

  Next, a method for controlling the tilt angle of the antenna vertical pattern will be described with reference to FIG.

  Initial setting is performed (step S802).

  Next, the antenna pattern control unit 104 performs an update for a certain period using the uplink interference amount of the local station as a radio resource (step S804).

  Next, the antenna pattern control unit 104 performs an update for a certain period using the total transmission power of the local station as a radio resource (step S806).

  Next, the antenna pattern control unit 104 updates the tilt angle after updating for a certain period using the uplink interference amount of the local station as a radio resource and the total transmission power of the local station as a radio resource. The tilt angle after the comparison is compared, and the larger one is set as the tilt angle of the own station (step S808).

  As described above, by setting the tilt angle according to the tighter one of the uplink interference amount and the total transmission power, the system capacity can be improved in any cell radius and traffic distribution.

  Next, another tilt angle control method of the antenna vertical pattern will be described with reference to FIG.

  The antenna pattern control unit 104 updates the tilt angle for a certain period using the uplink interference amount of the local station as a radio resource (step S902).

  Next, the antenna pattern control unit 104 determines whether or not the tilt angle after a certain period of update is greater than or equal to a specified value (step S904).

  If the updated tilt angle is equal to or greater than the preset specified value (step S904: YES), the antenna pattern control unit 104 sets the updated tilt angle as the tilt angle of the local station and ends the update (step S906). .

  On the other hand, when the updated tilt angle is less than the preset specified value (step S904: NO), the antenna pattern control unit 104 updates the tilt angle again using the total transmission power of the local station as a radio resource. (Step S908), the update is terminated after a certain period of time (Step S910).

  Here, the specified value is set to about 1 degree to 5 degrees in accordance with a cell radius range assumed in advance. If the tilt angle after updating using the amount of uplink interference is less than the specified value, the system capacity is limited due to the “downcompression” of the total downlink transmission power, so control is performed using the total downlink transmission power. I do. First, the control is performed using the uplink interference amount because the uplink interference amount decreases as the tilt angle increases, and the uplink interference amount increases as the tilt angle decreases.

  On the other hand, when the total downlink transmission power is used, when the tilt angle is increased, the transmission power control is performed to compensate for the factor that the total downlink transmission power decreases because the cover area decreases and the decrease in antenna gain. There is a factor that the total downlink transmission power increases. For this reason, since stable control can be realized by using the uplink interference amount as a reference, control based on the uplink interference amount is performed first.

  The antenna 106 emits radio waves with the antenna pattern designated by the antenna pattern control means 104.

  With this configuration, it is possible to construct a cellular mobile communication system that achieves high system capacity by achieving automatic setting and automatic update of antenna patterns and effectively reducing interference with other cells.

  An operation step of a base station in a radio communication system to which an antenna pattern control method according to an embodiment of the present invention is applied will be described with reference to the drawings.

  FIG. 10 is a flowchart illustrating the antenna pattern control method according to the present embodiment, that is, the operation of the base station according to the present embodiment.

  The radio resource usage status determining unit 102 observes the radio resource usage (uplink interference amount, total transmission power, etc.) of the base station 100 for a certain period (step S1002), and calculates a statistical value, for example, an average value (step S1002). S1004).

  Next, the radio resource usage status determination unit 102 determines the radio resource usage status (step S1006).

  A method for determining the radio resource usage status will be described. As described with reference to FIG. 2, when a statistical value, for example, an average value, a median value, a variance, a standard deviation, etc. of a radio resource usage amount for a certain period is equal to or greater than a first specified value, The usage status is determined as “tight”. When the statistical value is less than the first specified value and less than the second specified value, it is determined as “tight”. If the statistical value is less than the first specified value and greater than or equal to the second specified value, it is determined as “appropriate”.

  For example, in the CDMA cellular system, the first specified value is set to a value 1 dB to 5 dB lower than the call admission control threshold. The second specified value is set to a value 2 dB to 7 dB lower than the call admission control threshold.

  Next, the antenna pattern control unit 104 receives the determination result of the radio resource usage status from the radio resource usage status determination unit 102, and determines the antenna pattern based on the result (step S1008). As described with reference to FIG. 3, the antenna pattern control unit 104 updates the tilt angle of the antenna vertical pattern of the own base station according to the determination result of the radio resource usage status of the own base station.

  If the wireless resource usage status is “tight”, the tilt angle is increased. If the radio resource usage status is “appropriate”, the tilt angle is not updated. If the wireless resource usage status is “surplus”, the tilt angle is decreased.

  As described above, whether the usage status of the uplink interference amount or the usage status of the total transmission power can be achieved as a result of the determination depends on the total transmission power, cell radius, and traffic distribution of the base station. Dependent. For example, when the total transmission power of the base station is large or the cell radius is small, the uplink interference amount is higher than the total transmission power, as in the case where the uplink traffic is larger than the downlink traffic. In a situation where there is a high possibility of tightness, it is better to use the usage status of the uplink interference amount as a determination result.

  On the other hand, for example, when the total transmission power of the base station is small or the cell radius is large, the total transmission power is larger than the amount of uplink interference as in the case where the downlink traffic is larger than the uplink traffic. In a situation where there is a high possibility that the user will be more strained, it is better to use the usage status of the total transmission power as a determination result.

  If the cell radius or traffic distribution cannot be predicted, and it is not possible to predict in advance which of the uplink interference amount and the total transmission power is more likely to be tight, as described with reference to FIG. The tilt angle of the antenna vertical pattern of the own base station is updated according to the judgment result of the usage situation of the uplink interference amount of the base station and the judgment result of the usage situation of the total transmission power of the own base station.

  If at least one of the usage status of the uplink interference amount and the usage status of the total transmission power is “tight”, the tilt angle is increased. If at least one of the usage status of the uplink interference amount and the usage status of the total transmission power is not “tight” and the usage status of the uplink interference amount and the usage status of the total transmission power are both “surplus”, the tilt angle is decreased. . The tilt angle is not updated unless at least one of the usage status of the uplink interference amount and the usage status of the total transmission power is “appropriate” and the other is “tight”. As described above, the system capacity can be improved in any cell radius and traffic distribution by performing control giving priority to the more constrained of the uplink interference amount and the total transmission power.

  Further, as described with reference to FIG. 8, the tilt angle after updating for a certain period using the uplink interference amount of the local station as a radio resource and the total transmission power of the local station as the radio resource is constant. The tilt angle after the period update is compared, and the larger one is set as the tilt angle of the own station. As described above, by setting the tilt angle according to the tighter one of the uplink interference amount and the total transmission power, the system capacity can be improved in any cell radius and traffic distribution.

  Further, as described with reference to FIG. 9, the tilt angle is first updated for a certain period using the uplink interference amount of the own station as a radio resource. At this time, if the updated tilt angle is equal to or greater than a preset specified value, it is set as the tilt angle of the own station. If the updated tilt angle is less than the preset specified value, the tilt angle is updated again using the total transmission power of the local station as a radio resource, and the update is terminated after a predetermined period. Here, the specified value is set to about 1 degree to 5 degrees in accordance with a cell radius range assumed in advance. If the tilt angle after updating using the amount of uplink interference is less than the specified value, the system capacity is limited due to the “downcompression” of the total downlink transmission power, so control is performed using the total downlink transmission power. I do. In this way, the system capacity can be improved in any cell radius and traffic distribution.

  Next, the antenna 106 transmits a signal with the antenna pattern designated by the antenna pattern control means 104 (step S1010).

  According to the embodiment of the present invention, it is possible to construct a cellular mobile communication system that achieves high system capacity by achieving automatic setting and updating of antenna patterns and effectively reducing interference with other cells.

  The base station apparatus and antenna pattern control method according to the present invention can be applied to a radio communication system.

It is a partial block diagram which shows the base station apparatus concerning one Example of this invention. It is explanatory drawing which shows the method of determining the radio | wireless resource usage condition concerning one Example of this invention. It is explanatory drawing which shows the tilt angle control method of the antenna vertical pattern concerning one Example of this invention. It is explanatory drawing which shows an example of the increase in system capacity | capacitance by antenna vertical pattern control. It is explanatory drawing which shows an example of the reduction of the other cell interference by antenna vertical pattern control. It is explanatory drawing which shows an example of the reduction of the other cell interference by antenna vertical pattern control. It is explanatory drawing which shows the tilt angle control method of the antenna vertical pattern concerning one Example of this invention. It is a flowchart which shows the tilt angle control method of the antenna vertical pattern concerning one Example of this invention. It is a flowchart which shows the tilt angle control method of the antenna vertical pattern concerning one Example of this invention. It is a flowchart which shows the antenna pattern control method concerning one Example of this invention.

Explanation of symbols

100, 100 ₀ , 100 ₁ Base station 102 Radio resource usage status determination unit 104 Antenna pattern control unit 106 Antenna 108, 108 ₀ , 108 ₁ , 108 ₂ Mobile station

Claims (12)

A base station apparatus in a cellular mobile communication system comprising:
Based on the statistics of the usage of radio resources including the uplink interference amount and the total transmit power observed in the base station apparatus, a radio resource use status determining means for determining the usage of radio resources in the base station apparatus;
Antenna pattern control means for designating an antenna pattern on the basis of the radio resource usage status determined by the radio resource usage status determination means;
An antenna that emits radio waves with an antenna pattern specified by the antenna pattern control means;
Equipped with a,
The radio resource usage status determining unit determines that the radio resource usage status of the base station apparatus is “tight” when the statistical value of the uplink interference amount in the base station apparatus for a certain period is equal to or greater than a first specified value. When the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and the second prescribed value. If it is above, it is judged as “appropriate”,
When the antenna pattern control means designates the depression angle of the main lobe of the antenna vertical pattern based on the determination result of the radio resource usage status by the radio resource usage status determination means, the radio resource usage status of the base station apparatus Is “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is increased, and when the usage status of the radio resource of the base station apparatus is “surplus”, the antenna vertical direction of the base station apparatus When the depression angle of the main lobe of the pattern is reduced and the usage status of the radio resource of the base station apparatus is “appropriate”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus is not updated, As the radio resource and the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus after updating for a certain period using the uplink interference amount of the base station apparatus Comparing the main lobe angle of the antenna vertical pattern of the base station apparatus after updating for a certain period using the total transmission power of the base station apparatus, the larger angle of depression is determined as the antenna vertical angle of the base station apparatus. the base station apparatus characterized that you set the depression angle of the pattern. A base station apparatus in a cellular mobile communication system comprising:
  Radio resource usage status determining means for determining radio resource usage status in the base station apparatus based on statistics of radio resource usage including the amount of uplink interference and total transmission power observed in the base station apparatus;
  Antenna pattern control means for designating an antenna pattern on the basis of the radio resource usage status determined by the radio resource usage status determination means;
  An antenna that emits radio waves with an antenna pattern specified by the antenna pattern control means;
  With
  The radio resource usage status determining unit determines that the radio resource usage status of the base station apparatus is “tight” when the statistical value of the uplink interference amount in the base station apparatus for a certain period is equal to or greater than a first specified value. When the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and the second prescribed value. If it is above, it is judged as “appropriate”,
  When the antenna pattern control means designates the depression angle of the main lobe of the antenna vertical pattern based on the determination result of the radio resource usage status by the radio resource usage status determination means, the radio resource usage status of the base station apparatus Is “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is increased, and when the usage status of the radio resource of the base station apparatus is “surplus”, the antenna vertical direction of the base station apparatus When the depression angle of the main lobe of the pattern is reduced and the usage status of the radio resource of the base station apparatus is “appropriate”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus is not updated, The depression angle of the main lobe of the antenna vertical pattern of the base station apparatus after updating for a certain period using the uplink interference amount of the base station apparatus is equal to or greater than a predetermined specified value In some cases, the depression angle is set to the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus, and when the depression angle is less than the specified value, the total transmission power of the base station apparatus is used as a radio resource for a certain period of time. A base station apparatus characterized in that the angle of inclination of the main lobe of the antenna vertical pattern of the base station apparatus after updating is set to the angle of depression of the main lobe of the antenna vertical pattern of the base station apparatus. A base station apparatus in a cellular mobile communication system comprising:
  Radio resource usage status determining means for determining radio resource usage status in the base station apparatus based on statistics of radio resource usage including the amount of uplink interference and total transmission power observed in the base station apparatus;
  Antenna pattern control means for designating an antenna pattern on the basis of the radio resource usage status determined by the radio resource usage status determination means;
  An antenna that emits radio waves with an antenna pattern specified by the antenna pattern control means;
  With
  The radio resource usage status determining unit determines that the radio resource usage status of the base station apparatus is “tight” when the statistical value of the uplink interference amount in the base station apparatus for a certain period is equal to or greater than a first specified value. When the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and the second prescribed value. If it is above, it is judged as “appropriate”,
  The antenna pattern control means uses the uplink interference amount of the base station apparatus when designating the depression angle of the main lobe of the antenna vertical pattern based on the determination result of the radio resource usage status by the radio resource usage status determination means. If at least one of the usage status of the radio resource determined in step S1 and the usage status of the radio resource determined using the total transmission power of the base station device is "tight", the main lobe of the antenna vertical pattern of the base station device Both the usage status of the radio resource determined using the uplink interference amount of the base station device and the usage status of the radio resource determined using the total transmission power of the base station device are “surplus”. The base station apparatus antenna vertical pattern main lobe depression angle is reduced, and the radio resource usage status determined using the uplink interference amount of the base station apparatus and If at least one of the usage statuses of the radio resources determined using the total transmission power of the base station apparatus is “appropriate” and the other is not “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is A base station apparatus that is not updated.   A base station apparatus in a cellular mobile communication system comprising:
  Radio resource usage status determining means for determining radio resource usage status in the base station apparatus based on statistics of radio resource usage including the amount of uplink interference and total transmission power observed in the base station apparatus;
  Antenna pattern control means for designating an antenna pattern on the basis of the radio resource usage status determined by the radio resource usage status determination means;
  An antenna that emits radio waves with an antenna pattern specified by the antenna pattern control means;
  With
  The radio resource usage status determining means determines that the radio resource usage status of the base station apparatus is “tight” when a statistical value of the total transmission power in the base station apparatus for a certain period is equal to or greater than a first specified value. When the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and greater than or equal to the second prescribed value. If it is
  When the antenna pattern control means designates the depression angle of the main lobe of the antenna vertical pattern based on the determination result of the radio resource usage status by the radio resource usage status determination means, the radio resource usage status of the base station apparatus Is “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is increased, and when the usage status of the radio resource of the base station apparatus is “surplus”, the antenna vertical direction of the base station apparatus When the depression angle of the main lobe of the pattern is reduced and the usage status of the radio resource of the base station apparatus is “appropriate”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus is not updated, As the radio resource and the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus after updating for a certain period using the uplink interference amount of the base station apparatus Comparing the main lobe angle of the antenna vertical pattern of the base station apparatus after updating for a certain period using the total transmission power of the base station apparatus, the larger angle of depression is determined as the antenna vertical angle of the base station apparatus. A base station apparatus that is set to a depression angle of a pattern. A base station apparatus in a cellular mobile communication system comprising:
Based on the statistics of the usage of radio resources including the uplink interference amount and the total transmit power observed in the base station apparatus, a radio resource use status determining means for determining the usage of radio resources in the base station apparatus;
Antenna pattern control means for designating an antenna pattern on the basis of the radio resource usage status determined by the radio resource usage status determination means;
An antenna that emits radio waves with an antenna pattern specified by the antenna pattern control means;
With
The radio resource use status determining means determines the usage of radio resources when statistics over a period of time of the total transmission power in the base station apparatus is a first predetermined value or more, the base station apparatus as "tight" When the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and greater than or equal to the second prescribed value. If it is
The antenna pattern control means, on the basis of wireless resource use status determining unit in the determination result of the wireless resource use status, when specifying the depression angle of the main lobe of the antenna vertical pattern, the usage of radio resources of the base station apparatus If There is a "tight", increasing the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus, when the use status of radio resources of the base station device is "excess", the antenna vertical of the base station apparatus reduce the depression angle of the pattern main lobe of the case usage of radio resources of the base station device is "properly", without updating the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus, the as radio resources The depression angle of the main lobe of the antenna vertical pattern of the base station apparatus after updating for a certain period using the uplink interference amount of the base station apparatus is equal to or greater than a predetermined specified value In some cases, the depression angle is set to the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus, when the depression angle is smaller than the specified value for a certain period using the total transmission power of the base station apparatus as a radio resource A base station apparatus characterized in that the angle of inclination of the main lobe of the antenna vertical pattern of the base station apparatus after updating is set to the angle of depression of the main lobe of the antenna vertical pattern of the base station apparatus. A base station apparatus in a cellular mobile communication system comprising:
Based on the statistics of the usage of radio resources including the uplink interference amount and the total transmit power observed in the base station apparatus, a radio resource use status determining means for determining the usage of radio resources in the base station apparatus;
Antenna pattern control means for designating an antenna pattern on the basis of the radio resource usage status determined by the radio resource usage status determination means;
An antenna that emits radio waves with an antenna pattern specified by the antenna pattern control means;
With
The radio resource use status determining means determines the usage of radio resources when statistics over a period of time of the total transmission power in the base station apparatus is a first predetermined value or more, the base station apparatus as "tight" When the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and greater than or equal to the second prescribed value. If it is
The antenna pattern control means, on the basis of the determination result of the wireless resource use status by the wireless resource use status determining means, when specifying the depression angle of the main lobe of the antenna vertical pattern, using the uplink interference amount of the base station apparatus at least one of the usage of radio resources determined using the total transmit power usage and the base station device of a wireless resource determined Te be a "tight", the antenna vertical pattern main lobe of the base station apparatus depression increases, both the usage of the radio resources determined using the total transmit power usage and the base station device of a wireless resource determined by using an uplink interference amount of the base station device is "surplus" If, to reduce the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus, the usage of radio resources determined by using an uplink interference amount of the base station apparatus and If at least one of the usage of the radio resources determined using the total transmission power of the base station device is "properly" other is not "tight", the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus A base station apparatus that is not updated. An antenna pattern control method in a base station apparatus in a cellular mobile communication system comprising:
The step of observing the amount of radio resources including the uplink interference amount and the total transmission power in the base station apparatus;
Based on the amount of radio resources that have been observed by the step of said monitoring, calculating a predetermined statistics;
Determining the usage status of the radio resource from the statistical value of the radio resource usage;
Specifying antenna patterns based on radio resource usage;
Emitting radio waves with the antenna pattern designated by the step of designating the antenna pattern;
I have a,
In the determining step, when the statistical value of the uplink interference amount in the base station apparatus in a certain period is equal to or more than a first specified value, the usage status of the radio resource of the base station apparatus is determined as “tight”, If the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and greater than or equal to the second prescribed value. If it is determined to be “appropriate”,
Wherein in the step of specifying the antenna pattern, based on the determination result usage of the radio resources by the step of determining, when specifying the depression angle of the main lobe of the antenna vertical pattern, the usage of radio resources of the base station apparatus Is “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is increased, and when the usage status of the radio resource of the base station apparatus is “surplus”, the antenna vertical direction of the base station apparatus When the depression angle of the main lobe of the pattern is reduced and the usage status of the radio resource of the base station apparatus is “appropriate”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus is not updated, The angle of the main lobe of the antenna vertical pattern of the base station apparatus and the radio resource after updating for a certain period using the uplink interference amount of the base station apparatus Then, comparing the main lobe angle of the antenna vertical pattern of the base station apparatus after updating for a certain period using the total transmission power of the base station apparatus, the larger depression angle of the base station apparatus An antenna pattern control method, wherein the angle of the antenna vertical pattern is set.   An antenna pattern control method in a base station apparatus in a cellular mobile communication system comprising:
  Observing the usage of radio resources including uplink interference and total transmission power in the base station apparatus;
  Calculating a predetermined statistical value based on the radio resource usage observed in the observing step;
  Determining the usage status of the radio resource from the statistical value of the radio resource usage;
  Specifying antenna patterns based on radio resource usage;
  Emitting radio waves with the antenna pattern designated by the step of designating the antenna pattern;
  Have
  In the determining step, when the statistical value of the uplink interference amount in the base station apparatus in a certain period is equal to or more than a first specified value, the usage status of the radio resource of the base station apparatus is determined as “tight”, If the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and greater than or equal to the second prescribed value. If it is determined to be “appropriate”,
  In the step of designating the antenna pattern, when the depression angle of the main lobe of the antenna vertical pattern is designated based on the determination result of the radio resource usage status in the determining step, the radio resource usage status of the base station apparatus Is “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is increased, and when the usage status of the radio resource of the base station apparatus is “surplus”, the antenna vertical direction of the base station apparatus When the depression angle of the main lobe of the pattern is reduced and the usage status of the radio resource of the base station apparatus is “appropriate”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus is not updated, The angle of inclination of the main lobe of the antenna vertical pattern of the base station apparatus after updating for a certain period using the uplink interference amount of the base station apparatus is a predetermined regulation. In the case of the above, the depression angle is set to the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus, and when the depression angle is less than the specified value, the total transmission power of the base station apparatus is used as a radio resource. An antenna pattern control method, comprising: setting a depression angle of a main lobe of an antenna vertical pattern of a base station apparatus after updating for a certain period to be a depression angle of a main lobe of the antenna vertical pattern of the base station apparatus.   An antenna pattern control method in a base station apparatus in a cellular mobile communication system comprising:
  Observing the usage of radio resources including uplink interference and total transmission power in the base station apparatus;
  Calculating a predetermined statistical value based on the radio resource usage observed in the observing step;
  Determining the usage status of the radio resource from the statistical value of the radio resource usage;
  Specifying antenna patterns based on radio resource usage;
  Emitting radio waves with the antenna pattern designated by the step of designating the antenna pattern;
  Have
  In the determining step, when the statistical value of the uplink interference amount in the base station apparatus in a certain period is equal to or more than a first specified value, the usage status of the radio resource of the base station apparatus is determined as “tight”, If the statistical value is less than the second prescribed value defined below the first prescribed value, it is determined as “surplus”, and the statistical value is less than the first prescribed value and greater than or equal to the second prescribed value. If it is determined to be “appropriate”,
  In the step of designating the antenna pattern, the uplink interference amount of the base station apparatus is used when designating the depression angle of the main lobe of the antenna vertical pattern based on the determination result of the radio resource usage status in the determining step. If at least one of the usage status of the radio resource determined in step S1 and the usage status of the radio resource determined using the total transmission power of the base station device is "tight", the main lobe of the antenna vertical pattern of the base station device Both the usage status of the radio resource determined using the uplink interference amount of the base station device and the usage status of the radio resource determined using the total transmission power of the base station device are “surplus”. In this case, the usage state of the radio resource determined by reducing the angle of depression of the main lobe of the antenna vertical pattern of the base station apparatus and using the uplink interference amount of the base station apparatus And when at least one of the usage statuses of the radio resources determined using the total transmission power of the base station apparatus is “appropriate” and the other is not “tight”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus The antenna pattern control method characterized by not updating.   An antenna pattern control method in a base station apparatus in a cellular mobile communication system comprising:
  Observing the usage of radio resources including uplink interference and total transmission power in the base station apparatus;
  Calculating a predetermined statistical value based on the radio resource usage observed in the observing step;
  Determining the usage status of the radio resource from the statistical value of the radio resource usage;
  Specifying antenna patterns based on radio resource usage;
  Emitting radio waves with the antenna pattern designated by the step of designating the antenna pattern;
  Have
  In the determining step, when the statistical value in a certain period of the total transmission power in the base station apparatus is greater than or equal to a first specified value, the usage status of the radio resource of the base station apparatus is determined as “tight”, When the statistical value is less than the first specified value and less than the second specified value, it is determined as “surplus”, and the statistical value is less than the first specified value and greater than or equal to the second specified value. Is determined to be “appropriate”
  In the step of designating the antenna pattern, when the depression angle of the main lobe of the antenna vertical pattern is designated based on the determination result of the radio resource usage status in the determining step, the radio resource usage status of the base station apparatus Is “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is increased, and when the usage status of the radio resource of the base station apparatus is “surplus”, the antenna vertical direction of the base station apparatus When the depression angle of the main lobe of the pattern is reduced and the usage status of the radio resource of the base station apparatus is “appropriate”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus is not updated, The angle of the main lobe of the antenna vertical pattern of the base station apparatus after updating for a certain period using the uplink interference amount of the base station apparatus, and radio resources Then, comparing the main lobe angle of the antenna vertical pattern of the base station apparatus after updating for a certain period using the total transmission power of the base station apparatus, the larger depression angle of the base station apparatus An antenna pattern control method, wherein the angle of the antenna vertical pattern is set.   An antenna pattern control method in a base station apparatus in a cellular mobile communication system comprising:
  Observing the usage of radio resources including uplink interference and total transmission power in the base station apparatus;
  Calculating a predetermined statistical value based on the radio resource usage observed in the observing step;
  Determining the usage status of the radio resource from the statistical value of the radio resource usage;
  Specifying antenna patterns based on radio resource usage;
  Emitting radio waves with the antenna pattern designated by the step of designating the antenna pattern;
  Have
  In the determining step, when the statistical value in a certain period of the total transmission power in the base station apparatus is greater than or equal to a first specified value, the usage status of the radio resource of the base station apparatus is determined as “tight”, When the statistical value is less than the first specified value and less than the second specified value, it is determined as “surplus”, and the statistical value is less than the first specified value and greater than or equal to the second specified value. Is determined to be “appropriate”
  In the step of designating the antenna pattern, when the depression angle of the main lobe of the antenna vertical pattern is designated based on the determination result of the radio resource usage status in the determining step, the radio resource usage status of the base station apparatus Is “tight”, the main lobe angle of the antenna vertical pattern of the base station apparatus is increased, and when the usage status of the radio resource of the base station apparatus is “surplus”, the antenna vertical direction of the base station apparatus When the depression angle of the main lobe of the pattern is reduced and the usage status of the radio resource of the base station apparatus is “appropriate”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus is not updated, The angle of inclination of the main lobe of the antenna vertical pattern of the base station apparatus after updating for a certain period using the uplink interference amount of the base station apparatus is a predetermined regulation. In the case of the above, the depression angle is set to the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus, and when the depression angle is less than the specified value, the total transmission power of the base station apparatus is used as a radio resource. An antenna pattern control method, comprising: setting a depression angle of a main lobe of an antenna vertical pattern of a base station apparatus after updating for a certain period to be a depression angle of a main lobe of the antenna vertical pattern of the base station apparatus.   An antenna pattern control method in a base station apparatus in a cellular mobile communication system comprising:
  Observing the usage of radio resources including uplink interference and total transmission power in the base station apparatus;
  Calculating a predetermined statistical value based on the radio resource usage observed in the observing step;
  Determining the usage status of the radio resource from the statistical value of the radio resource usage;
  Specifying antenna patterns based on radio resource usage;
  Emitting radio waves with the antenna pattern designated by the step of designating the antenna pattern;
  Have
  In the determining step, when the statistical value in a certain period of the total transmission power in the base station apparatus is greater than or equal to a first specified value, the usage status of the radio resource of the base station apparatus is determined as “tight”, When the statistical value is less than the first specified value and less than the second specified value, it is determined as “surplus”, and the statistical value is less than the first specified value and greater than or equal to the second specified value. Is determined to be “appropriate”
  In the step of designating the antenna pattern, the uplink interference amount of the base station apparatus is used when designating the depression angle of the main lobe of the antenna vertical pattern based on the determination result of the radio resource usage status in the determining step. If at least one of the usage status of the radio resource determined in step S1 and the usage status of the radio resource determined using the total transmission power of the base station device is "tight", the main lobe of the antenna vertical pattern of the base station device Both the usage status of the radio resource determined using the uplink interference amount of the base station device and the usage status of the radio resource determined using the total transmission power of the base station device are “surplus”. In this case, the usage state of the radio resource determined by reducing the angle of depression of the main lobe of the antenna vertical pattern of the base station apparatus and using the uplink interference amount of the base station apparatus And when at least one of the usage statuses of the radio resources determined using the total transmission power of the base station apparatus is “appropriate” and the other is not “tight”, the depression angle of the main lobe of the antenna vertical pattern of the base station apparatus The antenna pattern control method characterized by not updating.

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