Method for multi-mode handoff using preliminary time alignment of a mobile station operating in analog mode
AssigneeQUALCOMM Incorporated
InventorsEdward G. Tiedemann, Jr., Alejandro Raul Holcman
Life of this patent
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AssigneeQUALCOMM Incorporated
InventorsEdward G. Tiedemann, Jr., Alejandro Raul Holcman
Estimating the term…
A method for handoff of an analog connection within a cellular communication system which relies upon mobile station synchronization to a system time is disclosed herein. In order to reduce the acquisition time for a mobile station commencing operation in a digital mode, an estimate of master system time is transferred to the mobile station in analog mode before entering digital mode. The alignment operates within the protocols of existing analog systems, and hence requires only minimal changes in the mobile station. Time alignment may be initiated upon the base station sending to the mobile station a command to continually transmit a periodic signaling tone. The base station compares the phase of the signaling tone from the mobile station to a master system clock and determines an error signal. The base station notifies the mobile station to delay or advance in time the transmitted signaling tones based on the error signal. This procedure may continue until the calculated error falls below a predetermined level. Having attained time alignment, the base station is able to transfer to the mobile station absolute time of day information with increased accuracy. The mobile station is then commanded into digital mode where transition time is reduced to a level tolerable by the end user due to the performed alignment.
In a multi-channel communication system in which a mobile station is designed for communication with one or more base stations over analog and digital communication channels using analog and digitally modulated communication signals, respectively, a method for maintaining a connection initiated on the analog communication channel comprising the steps of:
In a code division multiple access (CDMA) spread spectrum communication system in which a mobile station is designed for communication with a base station over a digital communication channel using spread spectrum communication signals and over an analog communication channel using analog communication signals, a method for directing communications between said mobile station and said base station comprising the steps of:
In a multi-channel communication system in which a mobile station is designed for communication over an analog communication channel with a first base station using analog modulated communication signals, and for communication over a digital communication channel with a second base station using digitally modulated communication signals, a method for transferring a connection initiated on the analog communication channel to the digital communication channel comprising the steps of:
In a multi-channel communication system in which a mobile station is designed for communication with one or more base stations over analog and code division multiple access (CDMA) communication channels using analog and spread spectrum communication signals, respectively, wherein each base station transmits a common pilot signal of a different code phase with respect to other base stations in said system, a method for directing communications between said mobile station and said base stations comprising the steps of:
In a multi-channel communication system in which a mobile station is designed for communication with one or more base stations over analog and digital communication channels using analog and digitally modulated communication signals, respectively, a system for maintaining a connection initiated on the analog communication channel comprising:
In a code division multiple access (CDMA) spread spectrum communication system in which a mobile station is designed for communication with a base station over a digital communication channel using spread spectrum communication signals and over an analog communication channel using analog communication signals, a system for directing communications between said mobile station and said base station comprising:
Dependencies are inferred from the claim text.