Efficient time division duplex communication system with interleaved format and timing adjustment control
First Claim
1. A base station for use in wireless communication, comprisingstate control circuitry, said state control circuitry generating a repetitive clock signal defining a plurality of time frames, anda plurality of time slots defined by said clock signal in each time frame, each time slot defined by a base transmission interval reserved for a base station to transmit over a designated frequency band a base-to-user message to one of a plurality of user stations, and a user transmission interval reserved for one of said user stations to transmit a user-to-base message to said base station over said designated frequency band,wherein a first forward link transmission and a first reverse link transmission between said base station and a first user station of said plurality of user stations are separated by a number of intervening forward or reverse link communications, said number being variable according to a command from said base station.
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Accused Products
Abstract
A system for efficient time division duplex communication between a base station and a plurality of user stations over a single frequency band whereby guard time overhead is reduced through use of an interleaved frame structure and active adjustment of reverse link transmission timing as a function of round trip propagation time. A time frame is divided into a plurality of time slots. The base station transmits a forward link message to a first user station in a first time slot. The user station responds with a reverse link message in the following time slot. In the meantime, the base station receives a reverse link message from a second user station in the first time slot, and sends out another forward link message to a third base station in the first portion of the first time slot. The delay between transmitting the forward and reverse link messages to a particular user station allows for round trip propagation of the forward and reverse link messages. The interleaved frame structure provides for forward and reverse link messages to other user stations while the base station is waiting for a response from the user station, thereby maximizing time efficiency. The base station may, based on a measured propagation delay, command the user station to adjust its reverse link transmission timing so as to allow for reduced guard times.
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Citations
45 Claims
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1. A base station for use in wireless communication, comprising
state control circuitry, said state control circuitry generating a repetitive clock signal defining a plurality of time frames, and a plurality of time slots defined by said clock signal in each time frame, each time slot defined by a base transmission interval reserved for a base station to transmit over a designated frequency band a base-to-user message to one of a plurality of user stations, and a user transmission interval reserved for one of said user stations to transmit a user-to-base message to said base station over said designated frequency band, wherein a first forward link transmission and a first reverse link transmission between said base station and a first user station of said plurality of user stations are separated by a number of intervening forward or reverse link communications, said number being variable according to a command from said base station.
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7. A method of wireless communication comprising
transmitting, over a designated frequency band and in a first time interval of a time frame, a first base message from a base station directed to a first user station, receiving said first base message at said first user station, transmitting from a second user station, over said designated frequency band, a first user message directed to said base station, receiving said first user message at said base station in a second time interval of said time frame, transmitting, over said designated frequency band and in a third time interval of said time frame, a second base message from said base station to a third user station, transmitting from said first user station, over said designated frequency band, a second user message directed to said base station, and receiving said second user message at said base station in a fourth time interval of said time frame, wherein a number of time intervals between said first time interval and said fourth time interval is variable according to a command from said base station.
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12. A method of wireless communication comprising
transmitting, during a first time slot of a time frame, a first base-to-user message from a base station directed to a first user station, receiving, during said first time slot, a first user-to-base message at said base station from a second user station, receiving, during said first time slot after said first user-to-base message, a control pulse preamble at said base station from a third user station, transmitting, during a second time slot of said time frame, a second base-to-user message from said base station directed to said third user station, and receiving, during said second time slot, a second user-to-base message at said base station from said first user station.
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16. A method of wireless communication, comprising
receiving, over a designated frequency band, a first control pulse preamble at a base station from a first user station, transmitting, over said designated frequency band, a first base-to-user message from said base station to said first user station, and after a time interval of sufficient duration to receive a first user-to-base message at said base station from a second user station, transmitting a second base-to-user message from said base station, and receiving a second control pulse preamble at said base station from a third user station, wherein said base station is capable of responding to said third user station in an adjacent time slot.
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20. A base station for use in wireless communication, comprising
state control circuitry, said state control circuitry generating a repetitive clock signal defining a plurality of time frames, and said clock signal further defining a plurality of time slots in each time frame, each of said time slots being defined by said clock signal into a base message interval reserved for transmission of a base-to-user message over a predetermined frequency band by a base station to a first user station in established communication with said base station, a user message interval reserved for reception of a user-to-base message over said predetermined frequency band at said base station from a second user station in established communication with said base station, and a preamble interval reserved for reception of a control pulse preamble over said predetermined frequency band from a third user station in established communication with said base station, whereby said base station is configured to be able to respond to said third base station in an immediately following time slot.
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24. A base station for carrying out wireless communication, comprising
state control circuitry, said state control circuitry generating a repetitive clock signal defining a plurality of time frames, and said clock signal further defining a plurality of time slots in each of said time frames, said clock signal defining in each of said time slots a base interval, reserved for transmission of either a base-to-user message sent by said base station to a first user station in established communication with said base station during said time slot, or a general polling message transmitted by said base station indicating availability of said time slot for communication, a user interval, reserved for reception of either a user-to-base message at said base station from a second user station in established communication with said base station, or a reply message at said base station from a third user station seeking to establish communication with said base station, and a preamble interval reserved for reception of a control pulse preamble from a fourth user station in established communication with said base station, whereby said base station is capable of responding to said fourth base station in an immediately following time slot.
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30. A user station for use in wireless communication, comprising
state control circuitry, said state control circuitry generating a repetitive clock signal defining a plurality of time frames, and a plurality of time slots defined by said clock signal in each time frame, each time slot defined by a base transmission interval reserved for a base station to transmit over a designated frequency band a base-to-user message to one of a plurality of user stations, and a user transmission interval reserved for one of said user stations to transmit a user-to-base message to said base station over said designated frequency band, wherein a first forward link transmission and a first reverse link transmission between said base station and a first user station are separated by a number of intervening forward or reverse link communications, said number being variable according to a command from said base station.
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36. A user station for use in wireless communication, comprising
state control circuitry, said state control circuitry generating a repetitive clock signal defining a plurality of time frames, and said clock signal further defining a plurality of time slots in each time frame, each of said time slots being further defined into by said clock signal into a base message interval reserved for transmission of a base-to-user message over a predetermined frequency band by a base station to a first user station in established communication with said base station, a user message interval reserved for reception of a user-to-base message over said predetermined frequency band at said base station from a second user station in established communication with said base station, and a preamble interval reserved for reception of a control pulse preamble over said predetermined frequency band from a third user station in established communication with said base station, whereby said base station is configured to be able to respond to said third base station in an immediately following time slot.
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40. A user station for carrying out wireless communication, comprising
state control circuitry, said state control circuitry generating a repetitive clock signal defining a plurality of time frames, and said clock signal further defining a plurality of time slots in each of said time frames, said clock signal defining in each of said time slots a base interval, reserved for transmission of either a base-to-user message sent by said base station to a first user station in established communication with said base station during said time slot, or a general polling message transmitted by said base station indicating availability of said time slot for communication, a user interval, reserved for reception of either a user-to-base message at said base station from a second user station in established communication with said base station, or a reply message at said base station from a third user station seeking to establish communication with said base station, and a preamble interval reserved for reception of a control pulse preamble from a fourth user station in established communication with said base station, whereby said base station is capable of responding to said fourth base station in an immediately following time slot.
Specification