CDMA radiotelephone having optimized slotted mode and long code operation

A radiotelephone, comprising:

• a receiver for receiving a wireless transmission;
• means for periodically activating at least said receiver to receive the wireless transmission during an assigned transmission period for operating said radiotelephone in a discontinuous reception mode, wherein the assigned transmission period is predetermined to have a duration that is a first integer multiple of a radiotelephone system time constant and also a second integer multiple of a partition of the assigned transmission period;
• and
• means, having an input coupled to an output of said receiver, for demodulating the wireless transmission that is received during at least a portion of the assigned transmission period.

A radiotelephone including a control mechanism for operating said radiotelephone in a discontinuous reception mode within a Code Division Multiple Access (CDMA) radiotelephone system, comprising:

• a receiver for receiving a CDMA transmission;
• a system time pseudonoise (PN) generator means;
• means for periodically activating at least said receiver to receive the CDMA transmission during an assigned slot of a paging channel, wherein the assigned slot is comprised of a plurality of frames and is predetermined to have a duration that is three times the duration of a rollover period of said system time pseudonoise (PN) generator means and four times the duration of one frame;
• and
• means, having an input coupled to said receiver, for despreading the CDMA transmission received during at least a portion of the assigned slot.

A Code Division Multiple Access (CDMA) radiotelephone system, comprising:

• at least one base station for transmitting a paging channel having a plurality of repeating paging channel slots each of which is comprised four frames;
• a radiotelephone comprising circuit means and control means for operating said radiotelephone within the CDMA radiotelephone system, said radiotelephone comprising,
• a receiver for receiving the paging channel transmission;
• a system time pseudonoise (PN) generator means;
• means, having an input coupled to said receiver, for despreading the paging channel transmission received during at least a portion of the assigned slot, wherein the assigned slot is predetermined to have a duration that is three times the duration of a rollover period of said system time pseudonoise (PN) generator and four times the duration of one frame.

A method for use in a CDMA radiotelephone for initializing a Long Code pseudonoise (PN) generator, comprising the steps of:

• determining a multi-bit mask that, when Exclusive-ORed with a current state of a Long Code PN generator, produces a state that the Long Code PN generator is known to assume at a predetermined future time;
• storing the mask in a memory of the radiotelephone;
• and
• in response to a requirement to initialize the Long Code PN generator at the predetermined future time, accessing the memory to retrieve the mask;
• and
• Exclusive-ORing the retrieved mask with a previous state of the Long Code PN generator to obtain a correct state.

A CDMA radiotelephone that includes a pseudonoise (PN) generator, comprising:

• memory means for storing a multi-bit mask that, when Exclusive-ORed with a current state of said PN generator, produces a state that said PN generator is known to assume at a predetermined future time;
• means, responsive to a requirement to initialize said PN generator at the predetermined future time, for accessing said memory means to retrieve the stored multi-bit mask;
• and
• means for Exclusive-ORing the retrieved multi-bit mask with a previous state of said PN generator to obtain a correct state.