초록 ▼

A method and apparatus reduces current consumption of a mobile communication unit, such as a cellular or mobile telephone that communicates with a base station by disabling a temperature controlled crystal oscillator and a code generator while the mobile communication unit is in a sleep mode of oper

A method and apparatus reduces current consumption of a mobile communication unit, such as a cellular or mobile telephone that communicates with a base station by disabling a temperature controlled crystal oscillator and a code generator while the mobile communication unit is in a sleep mode of operation, thereby reducing the sleep mode current consumed by the mobile communication unit. Prior to entering sleep mode, the mobile communications unit stores the state of the code generator and disables the temperature controlled crystal oscillator. Upon waking from sleep mode, the mobile communication unit calculates what the state of its code generator would have been if its temperature controlled crystal oscillator had not been disabled, and uses this calculated state to achieve synchronization with a code generator in the base station.

대표청구항 ▼

[ What is claimed is:] [1.]1. A method of reducing current consumption in a mobile communication unit having an oscillator driving a first pseudorandom code generator, wherein the mobile communication unit is adapted to communicate with a base station having a second pseudorandom code generator, the

[ What is claimed is:] [1.]1. A method of reducing current consumption in a mobile communication unit having an oscillator driving a first pseudorandom code generator, wherein the mobile communication unit is adapted to communicate with a base station having a second pseudorandom code generator, the method comprising the steps of:storing a first state of the first pseudorandom code generator that is substantially synchronized to the second pseudorandom code generator at a first time;entering a sleep mode for a predetermined period of time during which the oscillator and the first pseudorandom code generator are stopped;entering an awake mode wherein the oscillator and the first pseudorandom code generator are started;calculating a second state of the first pseudorandom code generator that is substantially synchronized to the second pseudorandom code generator at a second time, wherein the second state of the first pseudorandom code generator is calculated based on the first state of the first pseudorandom code generator;determining an estimated error between the second state of the first pseudorandom code generator and a state of the second pseudorandom code generator at the second time; andsearching a range of pseudorandom noise (PN) states dependent on the estimated error between the second state of the first pseudorandom code generator and the state of the second pseudorandom code generator at the second time to synchronize the first pseudorandom code generator to the second pseudorandom code generator.