JP2001320318A - Gps-supported cellular communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a radio communication system for discriminating a movement machine by using space diversity, on the basis of GPS data and also improving communication performance. SOLUTION: The traveling machine 202 acquires information, showing its own location, speed and time from a GPS satellite and transmits the information to a base station 100. The base station, equipped with a beam direction variable antenna array 700 group movement machines in its area, allocates a channel/ time slot (diffusion code in the case of CDMA) to the group and directs an antenna bean 110. When a movement machine moves in the area or travels into/out of the area, the base station reallocates a channel/time slot (diffusion code).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to wireless telecommunications systems.

[0002]

BACKGROUND: Due to the widespread use of TDMA and CDMA wireless telephone systems, many parts of the world have the systems needed to support proper wireless telephone communication. One common architecture for mobile communications is the cellular telephone system. Cellular telephone systems are mobile units that can be held
And a fixed transceiver unit, or "bases". When the mobile is turned on, it establishes contact with a nearby base station, which prepares a connection to the system. As the user of the mobile station moves, the mobile station communicates with a different base station, so that the user is always connected to some base station. The communication area of each base station is a “cell”.

[0003] Cellular telephone communications are performed via RF (radio frequency) signals. Due to the regulations, cellular telephone service providers can only use a limited range of frequencies. This limits the user capacity, or number of users, that a cellular telephone system can handle at any one time. Cellular telephone service providers are constantly seeking to increase the capacity of operating systems without compromising the quality of communication for individual users. There are several ways to allow multiple users access to the limited bandwidth. Currently, two commonly practiced methods are time division multiple access (TDMA) and code division multiple access (CDMA).

[0004] Time division multiple access increases capacity by dividing system bandwidth into frequency channels using frequency division multiple access and further dividing each channel into individual time slots. Each user transmits in a given time slot of a given channel. By reading data from a given time slot in the frequency channel,
Individual mobile user data can be extracted from the system bandwidth. The capacity of this data transfer method is finite. That is, once all the time slots of the available channels are in use, the system cannot accept subsequent users.

[0005] Code division multiple access offers different communication methods. The frequency channels in CDMA are wider and each channel occupies much more system bandwidth than the individual channels in TDMA. (The bandwidth of a typical TDMA frequency channel can be 30 kHz and the bandwidth of a typical CDMA frequency channel can be 1.5 MHz.) Many users transmit and spread simultaneously on the same bandwidth. Individual users are identified by a set of codes. Each code channel in the wideband frequency channel has its own spreading code that is (ideally) orthogonal to all other spreading codes used in the system. The spreading code modulates each signal separately. Proper demodulation ("despread
ing) The predetermined signal is extracted from all the signals by applying the code ")". Signals that do not correspond to the despreading code appear as noise and are rejected.

Background: Limitations of TDMA and CDMA Both TDMA and CDMA have limitations in capacity and communication quality.

[0007] As discussed above, the capacity of a TDMA system is finite and limited. Channel and time
When the slots are all occupied, they cannot accept other users. System bandwidth can be reused only when base stations transmitting on the same frequency are far enough apart so as not to cause interfering waves of interest. TDMA systems typically divide the available bandwidth into clusters, or groups of adjacent cells. The capacity of the system can be increased by reducing the transmit power of the cell (and the area covered by the cell), which means that the available bandwidth within a given area is reused more frequently. Enable. Since the bandwidth allocated to a given cell in the cluster can only be reused by other cells that are far enough away, co-channel interference (which is the interference caused by nearby cells using the same frequency) is almost It doesn't matter. Reusing bandwidth is a TD
Required to maximize MA system capacity.

[0008] To further increase capacity, the cell is divided into multiple sectors, each transmitting a different set of frequency channels. Using a limited directional antenna (as opposed to an omni-directional antenna) means that fewer signals using the same frequency will interfere with the signal in a given cell, reducing co-channel interference. is there.

[0009] The limitations of CDMA systems are different from TDMA systems. Since all mobile stations transmit independently, their relative time delays have a random distribution. This can be attributed to, for example, variations in signal arrival times caused by multipath propagation.
A problem arises when the signal is demodulated at the base station because the set of spreading codes that remain completely orthogonal in actual use is not known). Non-orthogonal components of other signals appear as interference waves in the demodulated signal.

[0010] The way of reducing the capacity of CDMA is different from the capacity of TDMA. As the number of users increases, the number of signals to filter any given signal increases. The more signals that are transmitted, the greater the interference that will appear when the signals are decoded. Only one user can be accepted at any one time, but the signal-to-interference ratio (signal-to-in
terference ratio) (S / I) deteriorates slightly. Therefore, CDMA is limited by interference.

Background: Global Positioning System (GPS) GPS is a satellite navigation system that provides specially encoded satellite signals. Once these signals have been processed by the GPS receiver, the position, speed and time of the receiver can be determined. The Global Positioning System has three main segments: a Space segment, a Control segment, and a User segment.

The spatial segment is composed of GPS satellites that transmit radio signals from the spatial orbit of GPS satellites. These satellites are located so that at least 5 GPS satellites are visible from any point (on a flat earth) at any given time.

The control segment consists of tracking stations located around the world, which monitor signals from satellites and incorporate these signals into each satellite's orbit model. These models calculate accurate orbit data and clock correction for each satellite.

[0014] The user segment is composed of a GPS receiver and a user community. Typically, a receiver uses signals from at least four GPS satellites to calculate its position, speed, and time.

GPS-Assisted Cellular Communication This application discloses using position and speed information from a GPS receiver inside a mobile telephone unit to improve communication performance. Mobile device is GP
Upon receiving the S data (mobile station position, speed and time), the mobile station relays this data to the base station via the existing cellular background channel.

If the location and speed of the mobile terminal are known at the base station (via periodic or commanded messages transmitted on a digital control channel), the overall network performance can be improved. This data allows the use of spatial diversity in addition to frequency channels and time division diversity (in a TDMA system) or spread code diversity (in a CDMA system) to enable different mobile stations to be distinguished. Spatial diversity as a system parameter is, of course, independent of frequency, time or spreading code.

Spatial diversity is based on the multi-beam steerable antenna of a base station.
Antenna) is particularly useful when used in combination. Knowledge of the location and speed of the target mobile can be used to transmit directly from the base station to that particular mobile. This can increase the cell size without increasing the power of the base station or the transmitter of the mobile station, and can also reduce the power required by both the base station and the mobile station. Thus, mobile telephone service providers can deploy fewer cell sites to serve a given area. Since the base station receiver is more sensitive in the direction of the desired mobile, the handset can also have lower power. This increases the service life of the battery and the user's talk time. Communication is possible even in an environment where the signal-to-interference ratio is small (for example, inside an urban building) as compared with the omnidirectional antenna of the base station.

The use of spatial diversity can reduce the complexity for algorithms that reduce interference, or the same bit error rate (BER) in more noisy environments with algorithms that are equivalent in complexity. ) Performance. Each base station
Since the mobile terminal has information on the position and distance of each mobile terminal, a near-far effect can be suppressed. This reduces complexity of the handset power control algorithm and reduces the need for base station-directed power control, which ultimately simplifies the handset and further reduces power consumption .

In some embodiments, the frequency and spreading codes are dynamically reassigned to take advantage of physically grouping mobiles. A variable beam direction antenna is used for target mobiles close to each other. Reassigning frequency and spreading codes uses system capacity more efficiently and reduces interference from friendly interferers belonging to the same system.

[0020]

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described with reference to the accompanying drawings, which show important illustrative embodiments of the invention, and which are incorporated into the invention. I will.

The numerous teachings of the present invention will now be described with reference to the presently preferred embodiment in detail. It should be understood, however, that such examples are merely illustrative of many of the many uses of the teachings of the invention that follow. In general, statements made in the specification of the present application do not necessarily limit all of the various aspects claimed by the present invention. Moreover, certain statements may apply to some inventions but not to others.

The preferred embodiment is designed for orbiting the earth.
Use mobile devices equipped with GPS devices that receive position, speed and time information from GPS satellites. This information is transmitted (periodically or by command) from the mobile station to the base station serving the particular mobile station via an RF signal. The GPS data in this preferred embodiment is based on the existing background data of the cellular system.
Since it is transmitted on a channel (eg, an access channel), it is only necessary to make simple modifications to the system to capture this data.

The base station is equipped with an antenna array having a plurality of narrow beams with variable beam directions. In the preferred embodiment, although not required, there is at least one antenna beam for each mobile. Narrow beam steerable antenna arrays provide more directed gain range than omni-directional antennas.
regions of gain). The antenna beam is
Since the adjustment can be made within the range covered by the information, when the position information from the mobile device is received by the base station, the mobile device can be readjusted to compensate for the mobile device moving and the mobile device entering and exiting the system. FIG. 1 shows a beam 1 of the variable beam direction antenna.
10 shows a base station 100 having a large number of ten. Each beam can be directed in different directions. Since the area covered by each beam can be adjusted, interference sources can be reduced or avoided. FIG. 2 shows how the directional beam 110A can select a particular mobile station and how null can be placed at the interference source 204.

The use of more antennas than the number of mobile stations is due to the fact that the complex weighting parameters of the additional antennas can be used to increase the accuracy of placing nulls at various sources, and the direction of the antenna beam can be reduced. It offers certain benefits, such as less frequent changes. This will be discussed in detail in another embodiment.

The base station uses the mobile station's GPS location data to direct the antenna beam to each mobile station. As the mobile moves, the position and speed information provided by the GPS device can be used to direct the antenna beam to the new position of the mobile and to easily predict the subsequent position of the mobile.

A beam direction variable directional antenna (steerabl)
e directional antenna)
Brings many benefits. For example, the base station does not receive signals from interference sources belonging to the system (other mobile stations in different spatial regions that are not within antenna gain). The base station does not receive many signals from other base stations transmitting on the same frequency channel (for a TDMA system) or the same or adjacent spreading codes (for a CDMA system). The variable beam direction directional antenna is
Since the sensitivity of the target mobile station is increased, the radius of a predetermined cell is increased (advantageous in CDMA), or operation at lower transmission power is possible at the same radius (advantageous in CDMA and TDMA).

FIG. 3 shows the sequence of events when a mobile station enters a cell and accesses the system (step 30).
2). Next, the mobile station transmits GPS data to the base station via the standard background communication channel, and notifies the base station of the position, speed, and time of the mobile station (step 304). This data is obtained by the mobile device from a GPS receiver in the mobile device. After receiving this data, the base station assigns an antenna beam from its antenna array to that particular mobile station. This antenna beam is directed to the location of the mobile station determined by the received GPS data (step 306).

The ability to predict location greatly simplifies the tracking algorithm required for conventional adaptive antenna systems. Most cellular systems are frequency division duplex (FDD), which introduces inherent tracking errors because the transmit and receive channels are not at the same frequency, and the propagation effects of different frequencies limit the accuracy of the tracking. Have.

Although TDMA and CDMA differ in some aspects, the disclosed invention provides advantages for both systems.

As discussed above, a TDMA system operates by dividing the available bandwidth into individual frequency channels, and further dividing those channels into time slots.

Since the bandwidth in a TDMA system is reused in nearby cells (not neighboring cells), the system can accommodate more users. Signals from users at the borders of these nearby cells,
Cause co-channel interference. Prior art systems divide a cell into multiple regions and assign different frequency channels to different regions of a particular cell. As described above, the number of cells that cause co-channel interference is reduced, and the performance of the system is improved. FIG. 4a shows a cluster 400 of cells using omni-directional antennas with nearby cells 402 using the same frequency channel. The cells 402 shaded in this figure cause co-channel interference with each other. FIGS. 4b and 4c show cells divided into three or six regions, respectively, to further reduce co-channel interference. Variable beam direction directional antennas allow cells to be subdivided into more than this 60 degree sector, thus allowing for frequency and / or code reuse to further increase capacity.

The presently disclosed invention allows a cell of a base station to focus on a mobile station without directing an antenna beam to the interfering cell transmitting on the same channel, and the base station itself Co-channel interference can be further reduced by allowing its channel intended for the particular mobile station intended for the information to be transmitted to a smaller area. FIG. 5 illustrates the selectivity of a variable beam direction antenna and illustrates how a narrow beam antenna can target a desired mobile 202.

FIG. 7 illustrates a plurality of antenna elements 7 capable of simultaneously directing a plurality of antenna beams in different directions.
Beam steerable antenna array 700 comprising
Is shown.

[0034] CDMA systems utilize a second level of modulation ("spreading code") to distinguish the signals. As discussed above, the non-orthogonal components of other mobiles in the same system appear as noise in the decoded signal. By using the presently disclosed invention, very few mobile stations are received by the antenna beam dedicated to a particular mobile station, so that little interference is generated when the signal is decoded. Certain spreading codes may be used by other systems in some regions or may be used at different locations within the same system. These nearby areas that use the same spreading code can generate co-channel interference, similar to co-channel interference in TDMA systems, co-code interference. GPS data is
Providing the location of all users in the cell, the antenna array places nulls on interfering mobiles, while
Since the beam can be directed to the desired user, the signal to interference ratio for all users is increased.

Code reuse can also be performed in nearby areas due to the increased sensitivity and reduced interference made possible by the present invention. In addition, the ability to reuse the code results in little "packing" of the code. In other words, there is a very large relative Hamming distance between the different codewords used. The Hamming distance is a similarity between spreading codes. A code having a large relative Hamming distance has many symbols, among which the symbols are different. As will be appreciated by those skilled in the art, interference is reduced when the codes used are less similar.

By increasing the number of antennas, a CDMA system is also advantageous. Antenna parameters not used for transmission to the mobile station can be used to place nulls on interfering mobile stations by receiving GPS data from the desired mobile station and placing the mobile station null. Null is the area between the narrow beam antenna patterns where there is little gain. By nullifying the interfering mobile station, the communication performance is improved again.

Alternative Embodiment: Multiple Mobile Stations per Antenna Beam The presently disclosed invention may be implemented in several ways. The number of antenna beams in one of the embodiments is less than the total number of mobiles served by the cell. Utilizing the function of dynamically reallocating channels and spreading codes is combined with the location information of each mobile station to group mobile stations that are close to each other into one group.
To be able to reach one antenna beam,
Allows for frequency reassignment (in TDMA) or code (in CDMA). For example, in the case of TDMA, some time slots in a given frequency band are used by different users. Users in geographically close proximity to each other
Slots are allocated and the user is targeted for one antenna beam.

Similarly, even in CDMA, spreading codes having no similarity can be assigned to users who are geographically close to each other (the orthogonality between codes is increased to reduce interference after despreading). Codes can be dynamically reassigned. These users can be targets for one antenna beam.

FIG. 6 shows this processing. First, the mobile station accesses the cellular system (step 60).
2). Next, the mobile device transmits its own position, speed and time information obtained from its own GPS receiver to the base station (step 604). The base station classifies each mobile station for the location of other mobile stations in the system (step 606). If the system is TDMA, the base station dynamically reconfigures frequency channels and time slots during its own user so that mobile stations that are spatially close together communicate in different time slots on the same frequency channel. Assign (Step 6
08). The base station directs the antenna beam assigned to the mobile station group to the desired area (step 610). As the mobile enters and exits the area targeted by a particular antenna, the channels and time slots are dynamically reassigned again (step 612) and the process is repeated.

If the system is CDMA, the base station dynamically reassigns spreading codes so that spatially close mobiles communicate using codes with very large relative Hamming distances (step 614). . The base station directs the antenna beam assigned to contact the group of mobile stations to the desired area (step 616). When the mobile station enters and exits the area targeted by the antenna, the spreading code is dynamically re-assigned again (step 614) and the process is repeated.

Definitions: The following are definitions of the common meanings of some technical terms used in this application. (However, those skilled in the art will recognize from the context whether a different meaning is required.) Other definitions will be found in standard technical terminology dictionaries and journals. Spreading code: CDMA utilizes spreading codes to distinguish signals transmitted using the same bandwidth at the same time. Channel: A channel in TDMA is a frequency division of a specific frequency within the system bandwidth. In TDMA,
The channel is further divided into time divisions. The channel in CDMA is to assign a specific code to a predetermined frequency band. Time slot / time division: Time division within a channel. Multiple users in TDMA communicate on a given channel. Each user is assigned to a specific time slot in which data is transmitted. Base station: A fixed transceiver that communicates with a mobile device wirelessly, and ultimately connects the mobile device to another telephone system, such as a fixed-line telephone system. Cell: The area covered by a given base station. Mobile: A hand-held device for communicating with a base station via RF. It is usually called a cell phone. Spatial diversity: a function of a base station that distinguishes one mobile station from another based on location. Dynamic reassignment: In the case of TDMA processing, a function to reassign frequency channels to mobile devices and reassign time slots to the time axis so that communication is not interrupted. In the case of CDMA processing, a function to reassign the spreading code between mobile stations to the time axis so that communication is not interrupted.

Variations and Variations As will be appreciated by those skilled in the art, the inventive concepts described herein can be modified and varied over a very wide range of applications. Thus, the scope of a patented subject matter is not limited by the teachings of any particular example, but is defined only by the claims.

Although there are many ways to implement this idea, the specific embodiments described herein do not include all possible embodiments. For example,
In describing the present embodiment, TDMA and CDMA systems are referred to in detail, but GSM (Global System for Mobile Communication), FDMA, W-TDMA (Wideband TDMA), W-CDMA
(Broadband CDMA), PHS (Personal Handy Phone System), UMTS (Europe's Next Generation Mobile Phone System), PD
Other means of wireless communication, such as C (pan-Pacific or personal communication systems), wireless data systems, or analog systems, as well as future means that have not yet been developed, should incorporate the teachings of the present invention and incorporate the teachings of the present invention. Is within the intention of.

The idea of the present invention is not limited to the transmission of audio data. LMDS incorporating the disclosed ideas
(Local Multi-point Distribution Service) or MMDS (Multi-point Distribution Service)
Audio and video data transmission, such as the Microwabe Distribution System, is within the contemplation of the present application. Similarly, other forms of data transmission (eg, Internet access systems and local network remote access systems)
It is within the intent of the present application to incorporate the inventive ideas presented herein.

In other embodiments, the functions performed by the individual antenna elements may be performed by RF signal processing (eg, phase shifting between signals may be used to determine aspects of spatial diversity. May be).

The antenna used may be larger than the antenna shown in the preferred embodiment or may be driven with different dimensions.
The GPS system determines all three-dimensional physical dimensions above or below the ground. For example, in addition to changing the azimuth angle, it may be changed at a position higher than the ground surface in consideration of the topography. Antennas also have regional variations (ie, the distance from the antenna itself to the target of the antenna).

Reorienting the antenna may be performed after signal despreading (in a CDMA system). Further, the multi-element antenna may be equipped with a power amplifier that can be programmed to receive the phase and power control signals and control each element.

[0048] GPS assistance may be used to reduce multipath interference. Weakly reflected signals that interfere with the desired signal are filtered unless they emanate directly from the desired mobile.

The GPS data for the mobile device may be combined with terrain information and infrastructure information (eg, locations of major arterial roads) to more efficiently adjust the allocation of system resources. For example, knowing a particular area would make more use of the system at night, and knowing the number of mobiles that would normally occupy that area during that time would automatically allocate resources and generate the most demand. Be able to compensate for time. The time data provided by GPS satellites may be used to track the density of the mobile station during a certain time.
This provides a profile of system usage with obvious advantages in system design and resource allocation. The system itself can be designed to measure changes in system usage and automatically compensate.

With respect to the above description, the following items are further disclosed. (1) A wireless communication method including a mobile station and a base station, the method including: obtaining position information on each mobile station; and improving communication performance using the position information.

(2) The method according to item 1, wherein the position information is obtained from a positioning satellite by the mobile device.

(3) The method according to any one of (1) and (2), wherein the base station uses a beam direction variable antenna, and changes the direction of the antenna according to the position information. The method further comprising:

(4) The method according to any one of the above items (1) to (3), wherein the base station uses a variable beam direction antenna having a plurality of beams. Directing the antenna beam at the antenna.

(5) The method according to any one of the above items (1) to (4), wherein the step of acquiring speed information on each mobile station and the improvement of communication performance using the speed information And the step of causing.

(6) The method according to any one of Items 1 to 5, wherein the communication performance is partially improved by predicting the future position of the mobile station.

(7) A method of wireless communication having a mobile station and a base station, comprising: obtaining position information reported for each mobile station; and providing a beam direction variable antenna according to the position of the mobile station. Directing a beam.

(8) The method according to (7), wherein the position information is obtained by the mobile device from a positioning satellite.

(9) The method according to paragraph (7) or (8), wherein the beam of the antenna is redirected so as to null the interference source.

(10) A method of wireless communication having a mobile station and a base station, wherein the base station has a variable beam direction antenna array having a plurality of beams,
Transmitting location information from the mobile station to the base station; grouping the mobile stations according to the location of the mobile station; and wherein one antenna beam moves one or more mobile stations at similar locations. A method comprising: instructing an antenna array to contact a mobile station; and dynamically reassigning communication parameters used by the mobile station.

(11) The method according to item 10, wherein the communication parameters used by the mobile station are a channel and a time division in a time division multiple access system.

(12) The method according to item 10, wherein the communication parameter used by the mobile station is a code channel in a code division multiple access system.

(13) Item 10, Item 11 or Item 12
Clause 7. The method of clause wherein the communication parameters are reassigned to reduce communication interference.

(14) A method according to any one of clauses 10, 11, 12 or 13, wherein the antenna array is instructed to place a null at the interference source.

(15) In a wireless communication system, a mobile station communicating with a base station and a position receiver connected to the mobile station, wherein position, speed, and / or time information are transmitted.
The position receiver receiving from an external information source other than the base station, in the wireless communication system, the received information is used to improve the communication performance between the mobile station and the base station Wireless communication system.

(16) The system according to item 15, wherein the received information comprises GPS data, is transmitted to the base station, and is used by the base station.

(17) In the system according to the paragraph (15) or (16), the base station uses a variable beam direction antenna array having a plurality of beams and changes the direction of the beams according to the received information. system.

(18) Item 15, Item 16 or Item 17
Item 13. The system according to Item 1, wherein the received information is used to partially improve communication performance by predicting a future position of the mobile device.

(19) A radio communication system, comprising: a mobile station communicating with a base station; and a receiver connected to the mobile station and receiving information from a satellite, wherein the information is transmitted to the base station. In the wireless communication system including the receiver and a variable beam direction antenna at each base station, the variable beam direction antenna covers a predetermined area according to the information received by the base station. System directed.

20. The system according to claim 19, wherein the variable beam direction antenna is instructed to place a null at an interference source.

(21) In the system according to item 19 or 20, the communication system uses a communication method selected from a group consisting of time division multiple access, code division multiple access, and frequency division multiple access. system.

(22) In a radio communication method using a mobile station and a base station, the base station uses a beam direction variable antenna, and obtains position information of each mobile station. A method comprising: allocating system resources based on location information; and changing the system resource allocation based on a change in location of a mobile station.

(23) The method according to item 22, wherein the position information is acquired from a satellite by the mobile device,
A method transmitted to the base station.

(24) The method according to paragraph 22 or 23, wherein the base station uses a variable beam direction antenna array having a plurality of beams, and the base station specifies the position based on the position information. Redirecting the antenna beam to the mobile station.

(25) The method according to paragraph 22, wherein the base station uses a variable beam direction antenna array having a plurality of beams, further comprising the step of placing nulls at the interference sources. .

(26) A radio communication system that identifies a mobile station using spatial diversity based on GPS data and improves communication performance.

[Brief description of the drawings]

FIG. 1 is a diagram showing a base station provided with a plurality of variable beam direction directional antennas.

FIG. 2 illustrates a method of using a steerable beam antenna to avoid sources of interference, such as mobiles belonging to the system.

FIG. 3 shows a flowchart of a process used to transmit position data and change the direction of a variable beam direction antenna.

FIG. 4 is a diagram illustrating a cluster of cells and a method in which adjacent cells that reuse the same frequency channel cause co-channel interference and a method in which cells are subdivided to reduce co-channel interference; a shows a cluster of nearby cells using the same frequency channel and a cluster of cells using an omni-directional antenna, b shows a cell divided into three regions to reduce co-channel interference , C shows a cell divided into six regions in order to reduce co-channel interference.

FIG. 5 is a diagram illustrating a method in which a variable beam direction antenna can target a specific mobile device given position information.

FIG. 6 is a diagram showing a process of reassigning a channel or a code depending on a position of a user and an operation rate of an antenna.

FIG. 7 shows an antenna array with multiple elements that can change the direction of multiple antenna beams.

[Explanation of symbols]

REFERENCE SIGNS LIST 100 base station 110 beam steerable directional antenna beam 110A beam steerable beam 110B beam steerable beam avoiding interferer 200 antenna array 202 desired mobile station 204 interferer 400 cluster 402 first layer Reusable cell 700 Beam direction variable antenna array 702 Antenna element

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference)

Claims (2)

[Claims] 1. A method of wireless communication having a mobile station and a base station, comprising: obtaining position information on an individual mobile station; and improving communication performance using the position information. Method. 2. A wireless communication system, comprising: a mobile station that communicates with a base station; and a position receiver connected to the mobile station, wherein the mobile station transmits position, speed and / or time information to other than the base station. A wireless communication system comprising: the position receiver receiving from an external information source; the received information is used to improve communication performance between the mobile station and the base station.