Reducing shared downlink radio channel interference by transmitting to multiple mobiles using multiple antenna beams
First Claim
1. A method for use in a radio communications system with a radio base station that includes multiple antennas associated with a cell, comprising:
- selecting multiple mobile radios to receive a transmission over a shared radio channel during a predetermined transmission time interval, andtransmitting information over the shared radio channel to the multiple mobile radios in the cell during the predetermined transmission time interval using multiple antenna beams so that interference from the transmission appears as white noise in time and in space such that interference from the transmission is substantially equally distributed over frequency and in space,wherein the transmitting to the multiple mobile radios in the cell during the predetermined transmission time interval using multiple antenna beams prevents a flashlight effect from disrupting the channel quality detection performed by the mobile radios, andwherein the flashlight effect is an intense interference detected by a first mobile radio flashed by a beam transmission on the shared radio channel during one of the predetermined time intervals to another scheduled mobile radio thereby causing the first mobile radio to report a lower signal quality value for shared radio channel during the one predetermined time period, and wherein the flashlight effect negatively impacts scheduling on the shared radio channel because the first mobile radio reports the lower signal quality value for the shared radio channel which is substantially different than an actual signal quality value for the shared radio channel during the one predetermined time period as a result of the first mobile radio being flashed by a beam transmission.
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Accused Products
Abstract
A radio base station includes multiple antennas associated with a cell. Multiple mobile radios are selected to receive transmissions over a shared radio channel during a predetermined time interval. Information is transmitted over the shared radio channel to multiple mobile radios in the cell during the predetermined time interval using multiple antenna beams. As a result, interference from the transmission appears as white additive Gaussian noise in time and in space in the cell. A “flashlight effect” caused by a single beam transmission over the shared channel during a predetermined time interval that would normally detrimentally impact mobile channel quality detection is avoided. Other methods for avoiding the flashlight effect are described.
53 Citations
34 Claims
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1. A method for use in a radio communications system with a radio base station that includes multiple antennas associated with a cell, comprising:
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selecting multiple mobile radios to receive a transmission over a shared radio channel during a predetermined transmission time interval, and transmitting information over the shared radio channel to the multiple mobile radios in the cell during the predetermined transmission time interval using multiple antenna beams so that interference from the transmission appears as white noise in time and in space such that interference from the transmission is substantially equally distributed over frequency and in space, wherein the transmitting to the multiple mobile radios in the cell during the predetermined transmission time interval using multiple antenna beams prevents a flashlight effect from disrupting the channel quality detection performed by the mobile radios, and wherein the flashlight effect is an intense interference detected by a first mobile radio flashed by a beam transmission on the shared radio channel during one of the predetermined time intervals to another scheduled mobile radio thereby causing the first mobile radio to report a lower signal quality value for shared radio channel during the one predetermined time period, and wherein the flashlight effect negatively impacts scheduling on the shared radio channel because the first mobile radio reports the lower signal quality value for the shared radio channel which is substantially different than an actual signal quality value for the shared radio channel during the one predetermined time period as a result of the first mobile radio being flashed by a beam transmission. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A radio base station for use in a radio communications system, comprising:
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an adaptive antenna array including multiple antennas associated with a cell for generating multiple antenna beams, each beam covering only a portion of the cell; one or more transmit buffers; a channel scheduler for selecting multiple mobile radios to receive a transmission over a shared radio channel during a predetermined transmission time interval; and transceiving circuitry for transmitting information stored in the one or more transmission buffers over the shared radio channel via the adaptive antenna array to the multiple mobile radios in the cell during the same predetermined transmission time interval using multiple antenna beams to spread out the interference caused by the transmission so that interference from the transmission is substantially equally distributed over frequency and in space wherein the transmission via the adaptive antenna array to multiple mobile radios in the cell during the predetermined transmission time interval using multiple antenna beams prevents a flashlight effect from disrupting the channel quality detection performed by the mobile radios, wherein the flashlight effect is an intense interference detected by a first mobile radio flashed by a beam transmission on the shared radio channel during one of the predetermined time intervals to another scheduled mobile radio thereby causing the first mobile radio to report a lower signal quality value for shared radio channel during the one predetermined time period, and wherein the flashlight effect negatively impacts scheduling on the shared radio channel because the first mobile radio reports the lower signal quality value for the shared radio channel which is substantially different than an actual signal quality value for the shared radio channel during the one predetermined time period as a result of the first mobile radio being flashed by a beam transmission. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
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32. A method for use in a radio communications system with a radio base station that includes multiple antennas associated with a cell, comprising:
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selecting mobile radios to receive a transmission over a shared radio channel using a beam transmission sequence order; transmitting information over the shared radio channel using one beam to one or more mobile radios following the beam transmission sequence order for multiple predetermined time intervals; performing beam switching in accordance with the beam transmission sequence order after multiple transmission time intervals so that the flashlight effect is avoided, receiving reports from mobile radios of a detected channel quality of a pilot signal transmitted in the cell; and scheduling transmissions to one of the mobile radios over the shared radio channel for more than one transmission time interval in accordance with the beam transmission sequence based on the received reports, wherein the flashlight effect is an intense interference detected by a first mobile radio flashed by a beam transmission on the shared radio channel during one of the predetermined time intervals to another scheduled mobile radio thereby causing the first mobile radio to report a lower signal quality value for the shared radio channel during the one predetermined time period, and wherein the flashlight effect negatively impacts scheduling on the shared radio channel because the first mobile radio reports the lower signal quality value for shared radio channel which is substantially different than an actual signal quality value for the shared radio channel during the one predetermined time period as a result of the first mobile radio being flashed by a beam transmission. - View Dependent Claims (33, 34)
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Specification