Motorola Corporation

Mark L Oliboni

George A Drapac

Stephen H Woltz

Mark H Babcock

Michael J DeLuca

Walter L Davis

Richard Alexander Erhart

James G Mittel

Daniel A Morera

Carla J Maroun

Tuan S Hoang

Mark R Whitaker

Christopher B Rausch

Carol A McKinny

A method (600) that adjusts, at a predetermined boundary of a protocol utilized in decoding information from a signal received by a receiver (122), a symbol rate of the protocol (400). A processor (208) loads into a programmable counter (306), before a first boundary (412) of the protocol (400), a count of clock cycles defined to be received in the signal between the first and predetermined boundaries (414). The counter (306) counts from the first boundary (412), for a number of clock cycles equal to the count, a recovered bit clock synchronized with the signal and having the bit rate of the signal, to detect an occurrence of the predetermined boundary (414). The processor (208) loads, between the first (412) and predetermined boundaries (414), the another symbol rate into a bit-rate selection circuit (304). An output symbol rate of the bit-rate selection circuit (304) is enabled upon detecting the occurrence of the predetermined boundary (414), thereby adjusting the output symbol rate to the other symbol rate at the predetermined boundary (414).

Method and apparatus in a communication receiver for adjusting an

A peak and valley detection system and method are shown for a selective call receiving device (10). The peak and valley detection system quickly and accurately detects and tracks to the peak and valley of a two level and/or four-level signal. A signal value representing a received signal is compared by a CPU (28) to the sum of a peak variable and attack constant. The peak variable is updated to a first value if the received signal value is less than the sum and is updated to a second value if the received signal value is not less than the sum. Similarly, the received signal is compared by the CPU (28) to a difference between a valley variable and attack constant. The valley variable is updated to a third value if the received signal value is greater than the difference value and updated to a fourth value if the received signal value is not greater than the difference value. The peak and valley variables attack and decay at non-constant rates and independently of one another.

Peak and valley detector for a selective call receiving device

A symbol detector (110) for generating data symbols from a received signal having multiple signal voltages comprises an analog-to-digital converter (115) for converting the multiple signal voltages to digital values and peak and valley counters (310, 315) coupled to the analog-to-digital converter (115) for tracking the digital values to determine peak and valley values associated with high and low voltages, respectively, of the received signal. The symbol detector (110) further comprises calculation circuitry (120) coupled to the peak and valley counters (310, 315) for calculating upper, lower, and center thresholds in accordance with the peak and valley values and a decoder (125) coupled to the analog-to-digital converter (115) and the calculation circuitry (120) for generating the data symbols in accordance with the digital values and the upper, lower, and center thresholds.

Method and apparatus for generating threshold levels in a radio

In a device having a primary battery 10, a first voltage multiplier 20 is used to power digital electrical circuits 40 from the primary battery, and a second voltage multiplier 100-136 is used to recharge a backup battery 50 from the primary battery. The backup battery is charged to a voltage greater than the voltage generated by the first voltage multiplier. Methods of controlling the second voltage multiplier reduce its interference in measurement of device parameters, and reduce the power consumed from the primary battery.

Backup battery system for a portable electronic device

A data recovery device (208) for recovering data symbols having a period T from a received data stream. The data recovery device samples at least one data symbol in the received data stream at a rate determined by an integration envelope (301) having the period T. The samples are accumulated as a weighted sample count representing a recovered data symbol that is then stored as at least one recovered data bit.

Data recovery device

A paging receiver capable of bit synchronizing to one of two data rates. The receiver has a digital phase locked loop integrated onto a single integrated circuit clocked by a single frequency crystal. The paging receiver receives and synchronizes to a POCSAG signal which may be transmitted at either 512 bits per second or 1200 bits per second. The digital phase locked loop bit synchronizes to either data rate using a single crystal frequency of 76.8 kHz. The data rate is selected by a bit in the code paging receiver's code plug. The digital phase locked loop is constructed to have a substantially constant frequency to bandwidth ratio at both data rates.

Bit synchronizer

A battery saving apparatus for supplying power to a selective call communication receiver for enabling the detection of a synchronization codeword in data received in a predetermined signaling format comprises circuits for supplying power to the receiver, and for detecting valid data received during a first portion of the first predetermined time interval. Power is maintained to the receiver for the remainder of the first predetermined time interval when valid data is detected in the first portion. A synchronization codeword detector is included for detecting a synchronization codeword. When valid data is subsequently detected following a second portion of the first predetermined time interval and the synchronization codeword is not detected in the first predetermined time interval, power is maintained to the receiver for a second predetermined time interval to further enable detection of the synchronization codeword.

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Boynton Beach, FL, United States of America

Mark L Oliboni