Sharp Kabushiki Kaisha Corporation

Sharp Microelectronics Technology, Inc.

Bryan Severt Hallberg

A system and method of information correction using the independently derived parity of a received (n,k) cyclic digital codeword as a means for error checking so that error bursts of up to �(n-k)-.left brkt-top.log.sub.2 n.right brkt-top.! bit positions are corrected, where n is the number of bits in the codeword and k is the number of information bits in the codeword. The method incorporates prior art techniques of burst error correction using a generating polynomial and the generation of n syndromes, in which the bit positions of potential error bits in the received codeword are identified and replaced to generate potential replacement codewords for the received codeword. The method of correcting burst errors comprises the step of classifying replacement codewords with respect to their calculated parity. The method also comprises the step of using prior art error trapping techniques to supply a replacement codeword, as the corrected received codeword, when a single replacement codeword is generated. The method further comprises the step of matching the independently derived parity of the received codeword to the calculated parity of replacement codewords to select the corrected codeword when multiple replacement codewords are generated. An apparatus to correct burst errors is also disclosed.

System and method for correcting burst errors in digital information

A battery power supply transposition circuit has been provided to control the use of batteries in a power source supplying multiple voltages from multiple batteries that share a least one common battery. The transposition circuit includes switches to provide selective interconnections between the battery terminals which allow the order of the series connected batteries to be changed. A battery interconnection controller is also included to control interconnections between batteries, and so allow alternate batteries to be used as the at least one common battery. Changing the selection of the at least one common battery provides a means for minimizing differences in the rate at which the batteries are depleted.

Battery transposition system and method

A pager decoding system is provided which is compatible with the POCSAG encoding standard and which improves battery savings. The disclosed pager includes a baud rate detector for evaluating incoming transmissions to determined if the baud rate is compatible with the decoder, and a preamble detector for determining if preamble code is being transmitted. Baud rate information and preamble code information are sampled frequently when the pager's radio receiver is tuned on, to evaluate whether a valid transmission is being received and whether the pager's internal clock is synchronized with the transmission. In the methodology of the invention, when the pager is on standby and waiting to receive a transmission the radio receiver is periodically energized to search for valid data having the correct baud rate, and to search for POCSAG preamble code. Signals with the incorrect baud rate are quickly detected and the radio circuit is shut off to save battery power. Once a valid transmission has been acquired, the pager verifies that it is synchronized with the transmission by confirming the absence of preamble code and the presence of the correct baud rate. The pager's radio circuit does not need to be turned on to receive any of the synchronization signals after the pager's clock is initially synchronized. The invention maximizes battery savings by allowing the radio receiver to be shut off as soon as there is confirmation that the pager's address is not being sent, even before an entire code word has been received. A decoding method is also disclosed.

Growing community of inventors

Vancouver, WA, United States of America

Bryan Severt Hallberg