Abstract: A speech presence detector (101) includes a circuit input (105) to couple to a source of input signals. A control signal generator (113) generates control signals. A sampling circuit (112) samples the input signals as a function of the control signal. A processor (116, 616, or 916) is coupled to the sampling circuit to receive the signal samples. The processor is responsive to the sampled signals to identify a background noise threshold and detect the presence of speech. According to one embodiment, the method and apparatus employ a random control signal. According to another embodiment, the average frequency of the control signal is below the Nyquist rate. According to another embodiment, the processor is responsive to the received signal to count the number of samples within a predetermined amplitude range and identifies a background noise threshold from the number of samples which are in the predetermined range.

Abstract: An error detector circuit (300) for a discrete receiver indicates bad frames of binary information signals which contain distorted bits of data in numbers so great as to prevent a convolutional decoder (738) from generating, accurately, a decoded signal. A variable threshold generator (440) generates a variable threshold level according to the signal quality estimate for the received signal. When bit errors are detected in numbers beyond the variable threshold or when a first preselected value of the signal quality of a received signal combined with the detected number of bit errors forms a signal beyond a second preselected value, a bad frame is indicated.

Abstract: A communication device includes a housing (102), the housing has an opening (107) for receipt of a card having information stored therein. A card reader element (308) is positioned in the housing to communicate information from the card (108) to circuitry in the housing. A low profile ejection mechanism (402) is positioned on the housing. The ejection mechanism includes a spring (614) extending outwardly from the body toward the card reader element to push the card against the card reader element.

Abstract: A communication device (104) comprises a receiver circuit (108) receiving a modulated receive signal. A reference oscillator (132) generates a first clock signal at a first frequency, the first clock signal having harmonics. Circuitry (130) coupled to the reference oscillator and to the receiver responds to the first clock signal to produce a signal used by the receiver to reduce the frequency of the modulating signal. A frequency spreading circuit (134) is also coupled to the reference oscillator to modulate the first clock signal with a frequency spreading signal to produce a modulated clock signal including modulated harmonic frequency components. The frequency spreading circuit selectively combines the frequency spreading signal and the first clock signal. A control circuit (114) controls the frequency spreading circuit to modulate first clock signal with the frequency spreading signal when the selected received signal includes a harmonic of the first clock signal.

Abstract: A radio communication device a first housing portion (101) and second housing portion (103). The second housing portion is movably supported on the first housing portion to move between an extended position and a collapsed position. The second housing portion projects outwardly from the first housing portion in the open position. An antenna (107) is positioned in the second housing portion, the antenna includes a first component (640, 749, 859, 969) having a first tuning characteristic and a second component (647, 748, 858, 968) having a second tuning characteristic. One of the antenna components is tuned for a preferred characteristic when the radio telephone is collapsed and the other of the antenna components is tuned to the preferred characteristic when the antenna is extended.

Abstract: A microcontroller (100) with an expansion port (112) includes internal ROM (110) and EEPROM (109) and an external expansion port. The EEPROM internal to the microcontroller is programmable only when the CPU (102) is executing instructions within the internal ROM. Additionally, instructions associated with a secure operation stored in the internal ROM may not be accessed without first executing the beginning instruction of the secure operation. Attempts to begin execution of the secure operation at any point other than the legal entry address will cause the internal ROM (110) to be disabled.

Abstract: A system (100) and method of improving activation security allows a remote device (104) to identify that there is a difference between a first signal transmitted by a central site (102) and a first signal received by the remote device. A derived number is used. The derived number can be displayed to the user for verbal verification by the user, or the derived number can be used internally of the remote device, or the central site, for verification that is transparent to the user. A significant amount of security is added without substantially altering the communication protocol.

Abstract: A radio communication device menu system includes a memory (232) storing menu items. A controller (220) is coupled to the memory. A user controlled input (106) is coupled to the controller for manually inputting control signals to the controller. A display (108) is also coupled to controller to display signals from the controller. The memory includes a short menu and an extended menu. The controller is responsive to a predetermined actuation pattern of the user controlled input to select one of the extended and short menus as the active menu, and for scrolling through the selected one of the short and the extended menus. According to another aspect of the device, the user controlled input includes a clear key which is held for a first predetermined time period to return to a higher level in the active menu and the clear key is held for a second predetermined time period to exit the active menu.

Abstract: A circuit (103) for charging a battery (101) is connected to an input (126) for inputting a signal indicative of a temperature of the battery. A switch (108) selectively supplies power to the battery under the control of a control signal. A microcontroller (140) calculates a rate of change of the temperature signal and stores a peak rate of change during a battery charging interval. The microcontroller is operable to control the switch to disable charging of the battery when the temperature rate of change drops below the peak value by a rate of change threshold amount.

Abstract: An antenna assembly, and associated method, for a radio, such as a portable radiotelephone, which is of minimal physical dimensions and which is operable over a wide range of frequencies. A length of wire is helically-shaped and includes at least a portion of a winding. A capacitive top-hat is positioned at an end portion of the wire. By increasing the number of windings of the wire, the height of the antenna assembly is reduced, but such reduction also reduces the size of the bandwidth of frequencies over which the antenna assembly is operable. Increase in the size of the surface area of the capacitive top-hat increases the size of the bandwidth over which the antenna assembly is operable. Selection of the top-hat size and the number of windings permits beth physical dimensions of the antenna assembly and the size of the bandwidth to be selected.