Mobile station handover for base stations with adaptive antenna system
View Patent ↗Method for transferring service for a mobile station call signal from a first base transceiver station to a second base transceiver station in a wireless mobile telecommunication system, while a call is in progress. The method can include receiving at a base transceiver station an access burst from a mobile station with a call already in progress and requiring service from the base transceiver station. Based on the received access burst, the base transceiver station can electronically steer a beam of an adaptive antenna array of the base transceiver station toward a location of the mobile station.
1. A method comprising:
receiving, at a second base transceiver station, an access burst from a mobile station with a call already in progress with a first base transceiver station, and requesting service from said second base transceiver station;
electronically steering a beam of an adaptive antenna array of said second base transceiver station toward a location of said mobile station based on said access burst, wherein said beam of said adaptive antenna array exhibits gain in a first direction of said mobile station, and wherein said second base transceiver station creates an antenna pattern comprising nulls in a second direction of a second mobile station operating on a common RF carrier frequency;
receiving a predetermined number of additional access bursts by said second base transceiver station; and
determining, at said second base transceiver station, a set of weighting parameters based on said additional access bursts, wherein said set of weighting parameters is configured to produce said antenna pattern for said adaptive array.
2. The method according to claim 1 , further comprising generating a set of weighting parameters for said adaptive antenna array based on said access burst configured to produce said antenna pattern for said adaptive array exclusive of nulls intentionally positioned for avoiding interference with co-channel users.
3. The method of claim 1 , wherein said set of weighting parameters is configured to produce said antenna pattern for said adaptive array exclusive of nulls intentionally positioned for avoiding interference with co-channel users.
4. The method of claim 3 , further comprising responding, using said second base transceiver station, to said mobile station responsive to said additional access bursts.
5. A system, comprising:
a base transceiver station;
a receiver configured to receive at said base transceiver station an access burst from a mobile station with a call already in progress and requesting service from said base transceiver station;
a receiver signal processor for detecting said access burst; and
an adaptive array antenna system configured to electronically steer a beam produced by said adaptive array antenna system toward a location of said mobile station based on said access burst, wherein said beam of said adaptive antenna array system exhibits gain in a first direction of said mobile station, and wherein said base transceiver station creates an antenna pattern comprising nulls in a second direction of a second mobile station operating on a common RF carrier frequency,
wherein said receiver signal processor is configured to detect a predetermined number of additional access bursts before said base transceiver station transmits a response to said access burst,
wherein said adaptive antenna array system is configured to generate a set of weighting parameters for said adaptive antenna array based on a plurality of said predetermined number of additional access bursts,
wherein said adaptive antenna array is configured to determine said weighting parameters configured to produce said antenna pattern for said adaptive array exclusive of nulls intentionally positioned for avoiding interference with co-channel users.
6. The system according to claim 5 , wherein said adaptive array is configured to generate a set of weighting parameters configured to produce said antenna pattern for said adaptive array exclusive of nulls intentionally positioned for avoiding interference with co-channel users.