Motorola Corporation

Stephen V Cahill

Thomas J Walczak

Rashid M Osmani

William Paul Alberth, Jr

Randall Wayne Rich

Rolland R Hackbart

Ketan R Jahagirdar

Steven F Gillig

Michael P Metroka

Brian David Storm

Mark Joseph Callicotte

John W Diehl

Edward M Roney, Iv

Mark E Prill

Robert I Greene

Rashid M Osman

Peter A Tomasi

A portable communication device (,) includes a housing (,), a first display area (,), and a second display area (,). The first display area (,) is disposed in and outwardly directed from a front (,) of the housing (,), and the second display area (,) is disposed in and outwardly directed from a side (,) of the housing (,). The housing (,) may include a housing portion (,) movable to an open position and a closed position, where the second display area (,) is covered by the housing portion (,) when positioned in one of the first and the second positions.

Communication device having multiple displays and method of operating the same

A portable communication device (102) includes a housing (105), a first display area (130), and a second display area (132). The first display area (130) is outwardly directed from a side (122) of the housing (105), and the second display area (132) is outwardly directed from a front (120) of the housing (105). The housing (105) may include a housing portion (114) movable to an open position and a closed position, where the second display area (132) is covered by the housing portion (114) when positioned in one of the first and the second positions.

Communication device having multiple displays and method of operating

A radiotelephone (104) in a radiotelephone system (100) enters a low power sleep mode and times the duration of the sleep mode using a sleep clock generator (205) having a coarse resolution. The radiotelephone synchronizes timing of the radiotelephone to system timing using an oscillator (116) having a fine resolution. The radiotelephone then exits the low power sleep mode synchronized with system timing.

Radiotelephone and method for clock calibration for slotted paging mode

A method and apparatus, performed by a communication unit (101), for substantially eliminating undesired noise in an audible output signal (113) while a determined quality measure (114) of a received signal (107) is below a predetermined threshold (201). At least a portion the received signal (107) is stored for a predetermined period of time to produce a stored signal (109). A measure of pitch period (111) of the stored signal (109) is determined. When the determined quality measure (114) of the received signal (107) drops below the predetermined threshold (201), a portion of the stored signal (109) is used, responsive to the determined measure of the pitch period (111), to produce the audible output signal (113). To match a boundary between an end of the received signal (107) and an end of the portion of the stored signal (109) a discontinuity between the end of the received signal (107) and the end of the portion of the stored signal (109) at the boundary is determined. Values for a predetermined correction function responsive to the measured discontinuity are determined. The predetermined correction function is applied to the end of the portion of the stored signal (109) to align the end of the portion of the stored signal (109) with the end of the received signal (107) at the boundary. When the determined quality measure (114) of the received signal (107) rises above the predetermined threshold (201), the received signal (107) is used to produce the audible output signal (113).

Apparatus and method for substantially eliminating noise in an audible

An apparatus and method generates a shaped transition between the minimum and maximum output power levels of a transmitter (500). When the transmitter is turned on a stepped transition (415) is generated at the beginning (3) of the transition region (409) followed by a shaped transition (417) to the end (6) of the transition region (409). When the transmitter (500) is turned off a shaped transition region (417') is generated at the beginning (162) of the transition region (411) followed by a stepped transition (415') at the end (3) of the transition region (411). The stepped transition (415 or 415') is generated by adjusting a voltage controlled attenuator (545) and the bias of a power amplifier (545) in the transmitter (500). The shaped transition (417 or 417') is generated by processing transmitted information through finite impulse response filters (507 or 509) before or after the time slot permitted for transmitting information.

Apparatus and method for generating a transition between the on and off

A unique method for supervising a cellular telephone call between a base station and a radio telephone of a TDMA cellular communications system includes the steps of determining (304) that the assigned time slot is expected to be received within a predetermined amount of time; detecting the presence of the assigned time slot (306) within the predetermined amount of time; detecting the presence of the assigned DVCC when the assigned time slot is detected (308); incrementing a bad slot counter (316) [if] responsive to the assigned time slot is not detected within the predetermined amount of time or [if] responsive to the assigned DVCC is not detected; and terminating the communication (322) [if] when the bad slot counter reaches a predetermined maximum value. A good slot counter is incremented (310) when the assigned DVCC is detected in a burst. The good slot counter is reset (318) [if] when the assigned DVCC is not detected in the next burst, and both counters are reset (314) [if] when the assigned DVCC is detected in consecutive bursts.

Method for supervising TDMA radio frequency communications

An apparatus and method for automatically controlling a reference frequency (120) in a receiver (104) that receives either analog (116) or digital (136) information signals. The receiver (18) includes a frequency translator (109) for translating a carrier frequency (137) to an intermediate frequency (118) and maintaining the intermediate frequency (118) at a desired value responsive to the reference frequency (120). A first measure of frequency error (211, 212) is detected between the reference frequency (120) and the intermediate frequency (118). A second measure of frequency error (125, 126) is detected between the reference frequency (120) and the intermediate frequency (118). A current signal (213) is produced responsive to the first measure of frequency error (211, 212) when the receiver receives the analog information signal (116) and responsive to the second measure of frequency error (125, 126) when receiver receives the digital information signal (136). A frequency control signal (130) is produced responsive to the current signal (213) to automatically control thereby the reference frequency (120) when the receiver (18) receives either analog (116) or digital (136) information signals.

Apparatus and method for automatically controlling a reference frequency

The process of the present invention encompasses a method for automatically controlling the gain of a transponded modulation signal. The process receives a demodulated signal, detects whether SAT is present, and transmits the SAT. Before transmission, the transmitted SAT is adjusted for the gain of the modulator and for the gain of the receiver.

Automatic gain control of transponded supervisory audio tone

A radio receiver having a variable bandwidth received channel filter (113,115) to reduce interference is disclosed. A interference is detected by comparing received signal strength and received signal BER. The bandwidth of the filter (113,115) is narrowed to improve BER when a received signal strength is greater than a threshhold value and BER is worse than a threshhold value.

Interference reduction using an adaptive receiver filter, signal

An apparatus and method therefor substantially reducing the interference of a harmonic frequency component (301) of a clock signal with a filtered received signal (302), comprises a frequency spreading signal generator (127) and a signal modulator (125). The frequency spreading signal generator (127) produces a frequency spreading signal (130). The signal modulator (125) modulates the clock signal, produced by a clock signal generator (129), with the frequency spreading signal (130) to produce a modulated clock signal (131) including a modulated harmonic frequency component (303). The power level of a modulated harmonic frequency component (303), corresponding to the harmonic frequency component interfering with the filtered signal (202-204), is spread over a frequency bandwidth (f.sub.6 -f.sub.7) greater than the predetermined frequency bandwidth (f.sub.4 -f.sub.5) causing the power level of the modulated harmonic frequency component (303) within the predetermined frequency bandwidth (f.sub.4 -f.sub.5) to decrease.

Apparatus and method for reducing harmonic interference generated by a

A system, and associated method, for measuring a signal level of a signal received by a receiver, such as a radio telephone. The signal received by the receiver is applied to a variable amplifier. The amplification of the variable amplifier is adjusted such that an amplified signal generated therefrom is within the dynamic range of an intermediate frequency circuit. The level of amplification required to position the signal level of the amplified signal within the dynamic range of the intermediate frequency circuit is measured, and the signal level of the signal received by a receiver is calculated.

Signal level measuring system for a radio receiver

A TDMA cellular telephone (600) includes in its transmit signal path, microphone (608), vocoder (612), data format circuitry (601), quadrature modulator (602), 90 MHz local oscillator (606), transmitter with mixer (604), transmitter filter (618), and antenna (620). In its receive signal path, the TDMA cellular telephone (600) includes receiver filter (622) coupled to antenna (620), quadrature demodulator (624), and data deformat circuitry (625). The channel frequency of TDMA cellular telephone (600) is loaded into synthesizer (616) by microcomputer (614) and applied to transmitter (604) and demodulator (624). TDMA cellular telephone (600) is controlled by microcomputer (614) which includes a memory with a control and signaling computer program stored therein. Transmitter (604) includes novel power control circuitry (100) comprised of variable gain stage (104), mixer (106), bandpass filter (109), and directional coupler (112) in a forward path, and detector (116), A/D converter (118 ), digital controller (120), and D/A converter (126) in a feedback path.

Power control circuitry for a TDMA radio frequency transmitter

A gain control system for controlling signal levels of the signal received by a receiver. The gain control system is operable to control the signal levels of the signal when the signal is comprised of either a conventional, constant envelope signal, such as an FM signal, or a non-constant envelope signal, such as a TDMA composite modulated signal. The gain control system may be advantageously embodied in a dual-mode radiotelephone operable to receive both conventional, FM signals and TDMA, composite modulated signals.

Dual mode automatic gain control

A frequency control system for a dual-mode radiotelephone (152-238; 252-320) operative to receive either an FM signal or a DQPSK signal. In a first embodiment, when operative to receive the FM signal, the frequency of the reference oscillator (192) of the radiotelephone (152-222) is maintained in a fixed relation with the frequency of the FM signal. When operative to receive the DQPSK signal, the reference oscillator (192) is maintained in a fixed relation with the frequency of the DQPSK signal as determined by a digital signal processor (212). In a second embodiment, when operative to receive the FM signal, the frequency of an offset control oscillator (320) is maintained in a fixed relation with the frequency of the FM signal. When operative to receive the DQPSK signal, the reference oscillator (292) is maintained in a fixed relation with the frequency of the DQPSK signal as determined by a digital signal processor (312).

Dual mode automatic frequency control

A communications receiver (103) comprising a carrier recovery apparatus having an adjustable response time loop filter (123) responsive to carrier signal parameters determined by a signal processor (141) is disclosed. Signal reception under fading conditions is improved by detecting the received signal parameters in an energy level determinator (207), a rate of change of energy level determinator (209) and a look-up table value (221) corresponding to a position of TDMA time clock (219).

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Palatine, IL, United States of America

Stephen V Cahill