Standby power savings with cumulative parity check in mobile phones

In a radio communication system having at least one base station serving one or more mobile stations a receiver circuit in a mobile station comprising:

• a receiver section for receiving and demodulating messages from said at least one base station, said messages comprising repeated blocks of information bits, each block including a number of data bits and a number of check bits whose value depend on said data bits;
• a message check circuit for generating, upon reception of each repeated message, a check indication when said data bits are consistent with said check bits, wherein said message check circuit includes a cumulative majority vote circuit;
• and
• a power-down timer for turning off portions of said receiver circuit when a substantially error-free check indication is generated.

In a radio communications system having at least one base station serving one or more portable stations, a method to reduce standby power consumption of said portable stations comprising the steps of:

• transmitting messages from a base station, each message including a number of words and each word being repeated a number of times, at least one word including a number of data bits representing at least part of a identification number of any of said portable stations and including a number of check bits that depend on said data bits;
• resetting in a portable station a number of accumulators corresponding to said number of data bits and check bits;
• receiving first of said repeated words at said portable station and adding the values of each bit to a corresponding one of said accumulators;
• processing the values of said accumulator contents to determine if values corresponding to said data bits are consistent with values corresponding to said check bits and generating a check or no-check indication;
• if said no-check indication is generated, receiving another repeat of said word and adding its bit values to corresponding accumulators;
• repeating said processing step until all word-repeats have been accumulated or until said check indication is generated;
• upon a substantially error-free check indication being generated, powering down parts of said portable station for the remainder of said repeats of said word and then further processing said accumulator values to determine if part of said word matches a corresponding part of the said portable station's identification number and generating a match or no-match indication;
• and
• upon said no-match indication being generated, holding parts of said portable station powered down for a duration of transmission of the rest of the words in the same message.

In a radio telephone system having at least one base station serving one or more portable stations, a method to reduce standby power consumption of said portable stations comprising the steps of:

• transmitting messages from a base station in the form of blocks of information bits which are repeated a number of times, each block including a number of data bits and a number of check bits values of which depend on said data bits;
• determining majority values of said repeated blocks in a cumulative majority voting circuit;
• processing said majority values of said repeated blocks sequentially to determine whether said data bits in any block are consistent with said check bits and to generate a check or no-check indication correspondingly;
• and
• switching off parts of said portable phone upon generation of a substantially error-free check indication until the beginning of the next set of repeat blocks transmitted by said base station in order to save power.