CDMA mobile telephone
AssigneeNEC Corporation
InventorOsamu Hasegawa
Life of this patent
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Abstract
A CDMA mobile telephone allowing the drive mode to be automatically set and canceled without increasing the amount of hardware is disclosed. A frequency offset for each of N fingers is detected from despread data which are obtained by despreading received spectrum-spread data of M branches. Based on the detected N frequency offsets, it is determined whether the mobile telephone Is moving at speeds higher than a predetermined speed. An operation mode of the mobile telephone switches between a drive mode and a normal mode depending on whether the mobile telephone is moving at speeds higher than the predetermined speed.
Claims13
A mobile telephone apparatus operable in a CDMA (code division multiple access) communications system, comprising:
- a despreading circuit for despreading received spectrum-spread data of a plurality of branches to produce despread data each corresponding a plurality of fingers;
- a frequency offset detector for detecting a frequency offset for each of the fingers from the despread data:
- a movement determiner for determining whether the mobile telephone is moving at speeds higher than a predetermined speed, based on frequency offsets received from the frequency offset detector;
- and
- a mode controller for switching an operation mode between a drive mode and a normal mode depending on whether the mobile telephone apparatus is moving at speeds higher than the predetermined speed.
A method for detecting movement of a mobile telephone which Is operable in a CDMA (code division multiple access) communications system, comprising the steps of:
- a) detecting a frequency offset for each of N fingers from despread data which are obtained by despreading received spectrum-spread data of M branches, wherein N and M are integers greater than 1;
- and
- b) determining whether the mobile telephone is moving at speeds higher than a predetermined speed, based on N frequency offsets detected by the step (a).
Dependencies are inferred from the claim text.