Directivity control antenna apparatus for shaping the radiation pattern of antenna of base station in mobile communication system in accordance with estimated directions or positions of mobile stations with which communication is in progress

In a mobile communication system having at least one base station and a plurality of mobile stations, a directivity control antenna apparatus for said base station, comprising:

• an array antenna having an array of antenna elements, for transmitting and receiving radio waves to and from a mobile station which is located within a predetermined service area of the base station,
• frequency conversion means for converting respective received signals from said antenna elements to corresponding intermediate frequency signals or baseband signals during a receiving mode of operation of said base station, and for converting a transmission signal at the intermediate frequency or baseband frequency to transmission signals respectively corresponding to said antenna elements, at a transmission frequency, and supplying said transmission signals to said antenna elements during a transmission mode of operation of said base station,
• incoming direction estimation means for operating on said intermediate frequency signals or baseband signals from said frequency converter means during said receiving mode to estimate an incoming direction of radio waves from said mobile station, to thereby derive an estimated direction of said mobile station with respect to said base station, and for generating direction data indicative of said estimated direction,
• antenna directivity control means for controlling the phase and amplitude of said received signals corresponding to said antenna elements during said receiving mode and of said transmission signals respectively corresponding to said antenna elements during said transmission mode such as to determine a directivity of said array antenna, and
• peak generating means responsive to said direction data for generating control signals during said transmitting mode and said receiving mode to control said antenna directivity control means such as to form a peak of said directivity, oriented in said estimated direction of said mobile station;
• further comprising means for controlling said antenna directivity control means to establish a substantially uniform directivity of said antenna, wherein said incoming direction estimation means derives said estimated direction only while said condition of uniform directivity is established, and wherein said antenna directivity control means comprises means responsive to said control signals from said peak generating means for directly controlling the phase and amplitude of respective transmission signals and received signals of said antenna elements, which are at said transmission frequency.

In a mobile communication system having a base station and a plurality of mobile stations, a directivity control antenna apparatus for said base station, comprising

• a first array antenna having an array of antenna elements, for receiving radio waves from one or more mobile stations which are located within a predetermined service area of the base station,
• a second array antenna having an array of antenna elements, for transmitting and receiving radio waves for communication with a selected one of said mobile stations,
• frequency conversion means for converting respective received signals from said antenna elements of said first and second array antennas to corresponding intermediate frequency signals or corresponding baseband frequency signals during a receiving mode of operation of said base station, and for converting a transmission signal at the intermediate frequency or baseband frequency to transmission signals at a transmission frequency, respectively corresponding to said antenna elements of said second array antenna, and supplying said transmission signals to the corresponding antenna elements of said second array antenna during a transmission mode of operation of said base station,
• incoming direction estimation means for operating on said intermediate frequency signals or baseband signals derived by said frequency converter means from said received signals of the antenna elements of said first array antenna to thereby estimate respective incoming directions of radio waves from said mobile stations which are within the service area, for generating direction data indicative of said estimated directions, and for utilizing said direction data to estimate a total number of said mobile stations which are within said service area,
• antenna directivity control means for controlling the phase and amplitude of said received signals corresponding to said antenna elements of the second array antenna during said receiving mode and of said transmission signals respectively corresponding to said antenna elements of the second array antenna during said transmission mode such as to determine a directivity of said second array antenna, and
• peak generating means responsive to said direction data for generating control signals during said transmission mode and said receiving mode, to control said antenna directivity control means such as to form a peak of directivity of the second array antenna, oriented in an estimated direction of said selected mobile station.

In a mobile communication system having a base station and a plurality of mobile stations, a directivity control antenna apparatus for said base station, comprising

• a linear array antenna, having elements thereof spaced along an array axis,
• at least one offset antenna element, having directivity in a direction which is offset from said array axis of said array antenna by a fixed angle,
• incoming direction estimation means for receiving respective received signals of said offset antenna element and of a set of elements of the array antenna as received signals of a first antenna element set and receiving respective received signals of remaining elements of the array antenna as received signals of a second antenna element set, during a receiving mode of operation of said base station, for combining the received signals of the elements of the first antenna set and combining the received signals of respective elements of the second antenna set to thereby obtain two combined received signals, for obtaining the magnitude of the difference between these combined received signals, for estimating the direction at which a mobile station is located, based on that difference between the magnitudes, and generating direction data indicative of said direction,
• antenna directivity control means for controlling the phase and amplitude of said received signals corresponding to said antenna elements of the array antenna during said receiving mode and of transmission signals respectively corresponding to said antenna elements during a transmission mode of operation of said base station, such as to determine a directivity of said array antenna, and
• peak generating means responsive to said direction data for generating control signals during said transmission mode and said receiving mode, to control said antenna directivity control means such as to form a peak of directivity of said array antenna, oriented in said estimated direction.

In a mobile communication system having at least one base station and a plurality of mobile stations, a directivity control antenna apparatus for said base station, comprising:

• an array antenna having an array of antenna elements, for transmitting and receiving radio waves to and from a mobile station which is located within a predetermined service area of the base station,
• frequency conversion means for converting respective received signals from said antenna elements to corresponding intermediate frequency signals or baseband signals during a receiving mode of operation of said base station, and for converting a transmission signal at the intermediate frequency or baseband frequency to transmission signals respectively corresponding to said antenna elements, at a transmission frequency, and supplying said transmission signals to said antenna elements during a transmission mode of operation of said base station,
• incoming direction estimation means for operating on said intermediate frequency signals or baseband signals from said frequency converter means during said receiving mode to estimate an incoming direction of radio waves from said mobile station, to thereby derive an estimated direction of said mobile station with respect to said base station, and for generating direction data indicative of said estimated direction,
• antenna directivity control means for controlling the phase and amplitude of said received signals corresponding to said antenna elements during said receiving mode and of said transmission signals respectively corresponding to said antenna elements during said transmission mode such as to determine a directivity of said array antenna, and
• peak generating means responsive to said direction data for generating control signals during said transmitting mode and said receiving mode to control said antenna directivity control means such as to form a peak of said directivity, oriented in said estimated direction of said mobile station,
• wherein said mobile communication system includes a plurality of base stations and wherein said base stations are connected by communication lines for interchange of data, wherein each of said base stations has a fixed number of communication channels available thereto for communication with mobile stations, wherein each of said base stations further comprises means for deriving respective identification information for mobile stations which are within said service area of the base station, wherein said incoming direction estimation means utilizes said estimated incoming directions of radio waves from mobile stations to estimate a total number of said mobile stations which are currently located within said service area of said base station, wherein said incoming direction estimation means of each base station is further capable of deriving estimated direction data for mobile stations which are located within service areas which are outside said service area of said base station, and wherein each of said base stations further comprises
• mobile station position estimating means for receiving said direction data from said incoming direction estimation means, and for utilizing said direction data to estimate respective positions of mobile stations and generate position data indicative of said positions, and
• antenna directivity pattern selection means for receiving said estimated number of mobile stations from said incoming direction estimation means and said position data from said mobile station position estimating means, and for operating on said number of mobile stations and position data by
• based on said estimated number of mobile stations and allocated number of communication channels, determining a number of communication channels which are currently available to said base station or a number of mobile stations for which no communication channels are available,
• when it is found that that one or more communication channels are available, receive data from one or more other base stations specifying respective identification information for selected mobile stations which are located within service areas of said other base stations, obtain from said mobile station position estimating means respective position data for said selected mobile stations in addition to position data for the mobile stations which are located within the service area, and generate and supply to said antenna directivity control means control signals for controlling said antenna directivity control means to produce peaks of antenna directivity as required for communication by said base station with said mobile stations which are within the service area and with said selected mobile stations which are located within said service areas of the other base stations, and
• when it is found from said judgement operation that there is an insufficient number of communication channels available, sending to other base stations identification information for selected mobile stations which are within the service area of said base station.

In a mobile communication system having at least one base station and a plurality of mobile stations, a directivity control antenna apparatus for said base station, comprising:

• an array antenna having an array of antenna elements, for transmitting and receiving radio waves to and from a mobile station which is located within a predetermined service area of the base station,
• frequency conversion means for converting respective received signals from said antenna elements to corresponding intermediate frequency signals or baseband signals during a receiving mode of operation of said base station, and for converting a transmission signal at the intermediate frequency or baseband frequency to transmission signals respectively corresponding to said antenna elements, at a transmission frequency, and supplying said transmission signals to said antenna elements during a transmission mode of operation of said base station,
• incoming direction estimation means for operating on said intermediate frequency signals or baseband signals from said frequency converter means during said receiving mode to estimate an incoming direction of radio waves from said mobile station, to thereby derive an estimated direction of said mobile station with respect to said base station, and for generating direction data indicative of said estimated direction,
• antenna directivity control means for controlling the phase and amplitude of said received signals corresponding to said antenna elements during said receiving mode and of said transmission signals respectively corresponding to said antenna elements during said transmission mode such as to determine a directivity of said array antenna, and
• peak generating means responsive to said direction data for generating control signals during said transmitting mode and said receiving mode to control said antenna directivity control means such as to form a peak of said directivity, oriented in said estimated direction of said mobile station,
• wherein each of said mobile stations further comprises control signal transmitting means, for executing radio transmission using randomly selected frequency channels in randomly determined fixed duration time slots which are selected from a fixed sequence of time slots, said frequency channels being selected from a number N of frequency channels where N is a fixed integer, wherein said incoming direction estimation means of said base station performs said direction estimation based on respective received signals from said antenna elements after conversion to an intermediate frequency by said frequency converter means, and
• wherein said base station further comprises
• a set of variable-frequency bandpass filters for respectively transferring said intermediate frequency signals of said antenna elements to said incoming direction estimation means, and
• means for successively changing a passband of each of said variable-frequency filters in successive ones of N fixed-duration sub-intervals of each of said time slots, to enable said each variable-frequency filter to sequentially pass intermediate frequency values which corresponding to successive ones of said frequency channels, in successive ones of said sub-intervals, in each of said time slots.

In a mobile communication system having at least one base station and a plurality of mobile stations, a directivity control antenna apparatus for said base station, comprising:

• an array antenna having an array of antenna elements, for transmitting and receiving radio waves to and from a mobile station which is located within a predetermined service area of the base station,
• frequency conversion means for converting respective received signals from said antenna elements to corresponding intermediate frequency signals or baseband signals during a receiving mode of operation of said base station, and for converting a transmission signal at the intermediate frequency or baseband frequency to transmission signals respectively corresponding to said antenna elements, at a transmission frequency, and supplying said transmission signals to said antenna elements during a transmission mode of operation of said base station,
• incoming direction estimation means for operating on said intermediate frequency signals or baseband signals from said frequency converter means during said receiving mode to estimate an incoming direction of radio waves from said mobile station, to thereby derive an estimated direction of said mobile station with respect to said base station, and for generating direction data indicative of said estimated direction,
• antenna directivity control means for controlling the phase and amplitude of said received signals corresponding to said antenna elements during said receiving mode and of said transmission signals respectively corresponding to said antenna elements during said transmission mode such as to determine a directivity of said array antenna, and
• peak generating means responsive to said direction data for generating control signals during said transmitting mode and said receiving mode to control said antenna directivity control means such as to form a peak of said directivity, oriented in said estimated direction of said mobile station,
• wherein said incoming direction estimation means estimates said incoming direction of radio waves from said mobile station by utilizing a method that is based upon phase relationships and values of amplitude of said intermediate frequency signals or baseband signals respectively corresponding to individual ones of said antenna elements.

In a mobile communication system having at least one base station and a plurality of mobile stations, a directivity control antenna apparatus for said base station, comprising:

• an array antenna having an array of antenna elements, for transmitting and receiving radio waves to and from a mobile station which is located within a predetermined service area of the base station,
• frequency conversion means for converting respective received signals from said antenna elements to corresponding intermediate frequency signals or baseband signals during a receiving mode of operation of said base station, and for converting a transmission signal at the intermediate frequency or baseband frequency to transmission signals respectively corresponding to said antenna elements, at a transmission frequency, and supplying said transmission signals to said antenna elements during a transmission mode of operation of said base station,
• incoming direction estimation means for operating on said intermediate frequency signals or baseband signals from said frequency converter means during said receiving mode to estimate an incoming direction of radio waves from said mobile station, to thereby derive an estimated direction of said mobile station with respect to said base station, and for generating direction data indicative of said estimated direction,
• antenna directivity control means for controlling the phase and amplitude of said received signals corresponding to said antenna elements during said receiving mode and of said transmission signals respectively corresponding to said antenna elements during said transmission mode such as to determine a directivity of said array antenna, and
• peak generating means responsive to said direction data for generating control signals during said transmitting mode and said receiving mode to control said antenna directivity control means such as to form a peak of said directivity, oriented in said estimated direction of said mobile station,
• wherein, in said transmission mode of operation, said antenna directivity control means controls the phase and amplitude of said transmission signals corresponding to and respectively provided to said respective antenna elements by applying to each individual transmission signal input to said frequency conversion means for output to a respective one of said antenna elements a respective phase relationship and amplitude control value.

In a mobile communication system having at least one base station and a plurality of mobile stations, a directivity control antenna apparatus for said base station, comprising:

• an array antenna having an array of antenna elements, for transmitting and receiving radio waves to and from a mobile station which is located within a predetermined service area of the base station,
• frequency conversion means for converting respective received signals from said antenna elements to corresponding intermediate frequency signals or baseband signals during a receiving mode of operation of said base station, and for converting a transmission signal at the intermediate frequency or baseband frequency to transmission signals respectively corresponding to said antenna elements, at a transmission frequency, and supplying said transmission signals to said antenna elements during a transmission mode of operation of said base station,
• incoming direction estimation means for operating on said intermediate frequency signals or baseband signals from said frequency converter means during said receiving mode to estimate an incoming direction of radio waves from said mobile station, to thereby derive an estimated direction of said mobile station with respect to said base station, and for generating direction data indicative of said estimated direction,
• antenna directivity control means for controlling the phase and amplitude of said received signals corresponding to said antenna elements during said receiving mode and of said transmission signals respectively corresponding to said antenna elements during said transmission mode such as to determine a directivity of said array antenna, and
• peak generating means responsive to said direction data for generating control signals during said transmitting mode and said receiving mode to control said antenna directivity control means such as to form a peak of said directivity, oriented in said estimated direction of said mobile station,
• wherein in said receiving mode of operation, each of said respective antenna elements provides only a single received signal to said frequency conversion circuit, said frequency conversion circuit converting said received signals from each of said respective antenna elements into a plurality of intermediate frequency signals or baseband signals each respectively corresponding to only one of said received signals.