Abstract: A battery type detector for battery-using and battery-charging equipment is disclosed. Operational characteristics of the using and charging equipment are modified in accordance with the battery type detected.

Abstract: A single sync field (501) and multiple messages or message segments (503, 507, 511, and 515) are chained (407) together and encrypted (407) as a whole. When this encrypted chained message is received, it is decrypted as a whole (605), or in part (613) by setting up (609) and filling (611) a holding register with the encryption state of the encrypting device.

Abstract: A charging apparatus for a multiunit system includes a portable unit (101) and a base unit (103). The portable unit (101) includes first and second conductive contacts (119, 120) disposed on the portable unit (101) essentially opposite each other, and rechargable energy storage means (311) electrically coupled to the first and second conductive contacts (119, 120). The base unit (103) includes an indentation (124) formed in the base unit (103) and having a receiving surface shaped to receive at least a portion of the portable unit (101), first and second conductive protrusions (127, 129) extending outwardly beyond the receiving surface essentially opposite each other, and energy source means (131) electrically coupled to the first and second conductive protrusions (127, 129). The first and second conductive protrusions (127, 129) contact the first and a second conductive contacts (119, 120), respectively when at least a portion of the portable unit (101) is placed in the indentation (124).

Abstract: A method of controlling a receiver's on-time (313). The radio receiver (109) receives radio frequency signals (309) of a predetermined duration (305) at an interval having a predetermined time period (301). The method varies the receiver's on-time (415, 417) until the data detector (205) is on the verge of failing to detect all of the data.

Abstract: This method of key distribution locates (401,501) an individual communication unit (107) within an encrypted communication system with over-the-channel rekeying and then rekeys (415, 515) the unit. The method uses a key management controller (101) to manage and distribute keys (1541) and handle acknowledgments that are either immediate or delayed from receipt of the rekeying message.

Abstract: A multiplexed synchronous/asynchronous data bus is disclosed in which three bus lines are used to convey bidirectional synchronous data between at least two data devices at a relatively low data rate. Valid half duplex asynchronous data is applied at a higher data transfer rate to one of the three bus lines when only one of the bus lines is held in a logic high state.

Abstract: A portable radiotelephone with an integral voice recognition circuit is disclosed. Control of the voice recognition circuit is achieved with a foldable housing element which, in a closed position, covers an external keypad and control buttons. When the foldable housing element is in an open position, the portable radiotelephone is placed in an off-hook condition, the voice recognition circuit is activated, and the acoustic transducers are coupled to the voice recognition circuit. When the foldable element is in a closed position, the portable radiotelephone is placed in an on-hook condition, the voice recognition circuit is deactivated, and the electroacoustic transducers are coupled to the radiotelephone. A rapid closing and opening of the foldable element results in the voice recognition circuit being deactivated while the portable radiotelephone remains in the off-hook condition.

Abstract: This method of key distribution rekeys (605) a group of communication units (107) within an encrypted communication system with over-the-channel rekeying. The method uses a key management controller (101) to manage and distribute keys (1541) to a plurality of communication units and handle acknowledgments from the plurality of communication units that are delayed from receipt of the rekeying message. The rekeying message (615) is sent to any of the group of communication units (107) when an acknowledgment is not received (611) from one or more of the group of communication units (107).

Abstract: In frequency-hopping spread-spectrum systems, it is necessary to maintain frequency and bit synchronization (sync) between the transmitter and receiver in order to maintain quality data recovery at the receiver. Two transmissions in adjacent hop-time intervals may overlap because of various time delays within the system. Collision bits (203 and 207) are used to realign the transmitted messages in time. The base station (103) manufactures (401) the collision bits (203 and 207) and transmits them to the communication unit (101), which echoes back (503) the bits on its next transmission. If the bits received at the base station do not match the bits sent (407), the base station (103) initiates (409) collision maintenance such that the communication unit (101) can adjust its DPLL (331) to realign its transmissions in time.

Abstract: A convolutional decoder which assigns bit metrics to at least one bit of a symbol in a multilevel system. This decoder uses soft-decision Viterbi decoding with channel state information of a convolutionally-encoded communication transmitted using multilevel modulation.

Abstract: A channel bank speech synthesizer for reconstructing speech from externally-generated acoustic feature information without using externally-generated voicing or pitch information is disclosed. An N-channel pitch-excited channel bank synthesizer (340) is provided having a first low-frequency group of channel gain values (1 to M) and a second high-frequency group of channel gain values (+1 to N). The first group controls a first group of amplitude modulators (950) excited by a periodic pitch pulse source (920), and the second group controls amplitude modulators excited by a noise source (930). Both groups of modulated excitation signals are applied to the bandpass filters (960) to reconstruct the speech channels, and then combined at the summation network (970) to form a reconstructed synthesized speech signal. Additionally, the pitch pulse source (920) varies the pitch pulse period such that the pitch pulse rate decreases over the length of the word.

Abstract: A method and apparatus for remotely loading a telephone number into a mobile unit is disclosed. A registration computer in a credit card payment radiotelephone system places a call to a mobile radiotelephone unit and conveys a telephone number to the mobile unit which is stored at the mobile unit. This telephone number may later be recalled and transmitted by the mobile unit to accomplish a telephone call.

Abstract: A fractional-N synthesizer realizes automatic frequency control by adding (509) a digital representation of a determined frequency offset to a digital representation of applied modulation to create the modulus control of a programmable frequency divider (203).

Abstract: A digital cellular time-division multiple access (TDMA) system including a cellular switch and at least one base site employing 6:1 packing of transcoded information. The system incorporates the VSELP speech encoding algorithm to transcode data input from a cellular switch and a unique packing scheme to compress six messages channels worth of transcoded data into one 20 msec, 160 frame information block for transmission in one TDM timeslot. The compressed transcoded data is transmitted to a base-site on a T1 link where the six message channels worth of transcoded data is un-packed and coded. The coded information is then separated into two groups of three air-interface timeslots where two separate transmitters transmit one group each of three air-interface timeslots on two separate radio carrier frequencies.

Abstract: Orienting air-wound coils for placement by an automatic pick-and-place machine has been a problem for small electronic coils. Extracting damaged or deformed coils on a one-by-one basis is expensive and time-consuming. A feeder for air-wound coils uses a rod (101), a track (103), and a two-segment guide (105, 107) and has built-in mechanisms for rejecting damaged coils while feeding undamaged coils (111, 113) in the proper orientation to a pick-and-place machine.

Abstract: A latched accumulator fractional-N synthesizer having reduced residual error for use in digital radio transcievers is disclosed. The divisor of the frequency divider (103) of the synthesizer is varied with time by the summation of accumulator carry output digital sequences which result in frequency increments equal to a fraction of the reference frequency. The accumulators (615,617) are latched such that upon the occurrence of a clock pulse, data is transferred through each accumulator one clock pulse step at a time, such that the delay through the system is equal to that of only one accumulator. The latched output of the second highest order accumulator (619) is subtracted from the latched output of the highest order accumulator (621) and differentiated before being applied to the loop filter (109).

Abstract: A mechanism using a convertible mounting apparatus (103 and 105) for installing a communication device in both a horizontal and vertical configuration is described. The position of a wedge shaped platform (103) on the installation interface of the communications device (105) may be changed without separating the wedge shaped platform (103) from the installation interface of the communication device (105). In a vertical installation configuration, an aperture disposed in the installation interface of the communication device (105) further encompassed by the wedge shaped platform (103) provides a volume of space to store excess electrical cord (205) used for the communication device.