Beamforming and distributed opportunistic scheduling in wireless networks
AssigneesToshiba America Research, Inc., Telcordia Inc.
InventorsPraveen Gopalakrishnan, David Famolari, Shuichi Obayashi, Raziq Yaqub
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Abstract
A system and method that addresses the issue of inducing and exploiting multi-user diversity in, e.g., a WLAN system in a fully distributed and opportunistic manner. In some embodiments, the system includes: an access point having a variable beamformer configured to fluctuate signal strength as perceived by stations within a range of the access point; and a plurality of stations having modified distributed-MAC protocol such as to be channel-aware and opportunistic.
Claims21
A method for improving performance and/or energy utilization in a WLAN system, comprising:
- a) inducing fluctuations in signal strength transmitted from an access point to stations within a transmission range of the access point;
- and
- b) exploiting the induced fluctuations to make the stations channel aware and opportunistic.
A system for enhancing the performance of a WLAN system, comprising:
- a) an access point having a variable beamformer configured to fluctuate signal strength as perceived by stations within a range of the access point;
- b) a plurality of stations having modified distributed-MAC protocol such as to be channel-aware and opportunistic.
A method for enhancing a WLAN infrastructure system, comprising:
- using Distributed Opportunistic Scheduling (DOS) to exploit an access point radiation-beam induced multi-user diversity, providing variations in channel conditions among users, by transmitting back-to-back packets when channel conditions are favorable to reduce inter-transmission delays and by withholding transmission when channel conditions are un-favorable to reduce collision probability.
An improved WLAN system, comprising:
- a) an access point including:
- a distributed opportunistic scheduling unit configured to make scheduling decisions about which station to transmit packets to and which medium access mode to operate in;
- a poll control unit configured to send messages to stations and to receive responses from stations and to report to said distributed opportunistic scheduling unit based on said responses;
- and
- a beamform controller unit configured to control an antenna to form specific beam patterns;
- and
- b) at least one mobile station including:
- a distributed opportunistic scheduling unit configured to make scheduling decisions, which computes quality metrics with the access point and decides the mode of operation before starting a transmission process.
Dependencies are inferred from the claim text.