Abstract: Provided is a power supply circuit capable of operating with low noise and low power consumption. In a power supply circuit, a power level control signal Pa for controlling a power level of a power amplifier, and an internal current control signal Pb which is a result of smoothing the power level control signal Pa at predetermined time intervals, are inputted to an operational amplifier. The operational amplifier amplifies the power level control signal Pa, and controls an internal current thereof such that the internal current has a similar characteristic to that of the internal current control signal Pb. A power transistor amplifies an output of the operational amplifier, and supplies a voltage to the power amplifier.

Abstract: A communications structure may include a ground sheet, a feed conductor, and an active antenna branch electrically coupled to the feed conductor. A parasitic antenna branch may be electrically coupled to the ground sheet, and the active and parasitic antenna branches may be spaced apart. Moreover, the parasitic antenna branch may be between portions of the active antenna branch and the ground sheet.

Abstract: A base station (BS), a subordinated station (SS) and the transmission methods thereof for use in a multi-input multi-output (MIMO) network are provided. The BS stores resource allocation information about the MIMO network and an SS list, and generate a super frame according to the resource allocation information and the SS list. The super frame comprises a pilot pattern which comprises a plurality of pilots and data. The BS and SS both considers the pilot pattern as an identifier of the SS. When there are communications occurred between the BS and the SS, the BS/SS will confirm whether the pilot pattern of the super frame matches the identifier of the SS to reduce interference from other stations in the MIMO network.

Abstract: A radio frequency (RF) receiver includes an oscillator for outputting an oscillation signal from an output port thereof, a limiter for dividing the oscillation signal output from the oscillator into a branch signal at a predetermined dividing ratio outputting the branch signal, an amplifier for amplifying the branch signal output from the limiter, a frequency multiplier for outputting a local oscillation signal having a frequency obtained by multiplying a frequency of the amplified signal by a predetermined multiplicand, a mixer for mixing the local oscillation signal and a signal supplied from an antenna, a band-pass filter for receiving a signal output from the mixer and outputting an intermediate frequency (IF) signal, a detector for producing a detected signal by detecting the IF signal, and a controller connected directly with the output port of the oscillator for performing an operation according to the detected signal based on the oscillation signal as a clock signal.

Abstract: An agile RF tuner circuit capable of converting a wide portion of RF signal into an IF signal suitable for analog-to-digital conversion. The circuit up converts a received RF signal to a high IF signal and then down converts the high IF signal to a low IF signal. Embodiments of the RF circuit incorporate harmonic reject mixers to suppress harmonies and intermodulations typically associated with the frequency conversion process.

Abstract: An rf signal transmitter for transmitting rf signals through a plurality of antennas is described, which comprises: a transmit section adapted to selectively set, with respect to an input signal, the initial phase of an output to at least one of said antennas depending on a time or frequency region used for communication and to provide delay to the output on an antenna-by-antenna basis and on the basis of a transmission timing or a transmission frequency; and a quality information receive section for receiving quality information from destination station, i.e., a wireless terminal unit, said quality information concerning the rf signal transmitted from said transmit section and received at said destination station.

Abstract: According to one embodiment, a radio frequency receiver includes a quadrature mixer for converting radio frequency signals to baseband signals or intermediate frequency signals. The quadrature mixer includes an in-phase passive mixer and a quadrature-phase passive mixer. Each passive mixer includes a mixer core having a plurality of mixer input switch transistors and a plurality of output switch transistors connected to the mixer input switch transistors. Clock circuitry generates a first set of clock signals and a second set of clock signals. The first set of clock signals has a frequency twice that of the second set of clock signals. The first set of clock signals is arranged to drive the mixer input switch transistors and the second set of clock signals is arranged to drive the output switch transistors.

Abstract: A low cost, a low power consumption and a small size are three very important factors for a mobile communication terminal. A great problem is posed by the conventional technique using a DSP and a CPU independent of each other which requires two external memory systems. Also, two peripheral units are required for data input and output of the DSP and CPU. As a result, an extraneous communication overhead occurs between the DSP and the CPU. The invention realizes a mobile communication terminal system by a DSP/CPU integrated chip comprising a DSP/CPU core (500) integrated as a single bus master, an integrated external bus interface (606) and an integrated peripheral circuit interface. The memory systems and the peripheral circuits of the DSP and the CPU can thus be integrated to realize a mobile communication terminal system low in cost and power consumption and small in size.

Abstract: A method for handing-off a mobile node (MN) from one network interface to another network interface, the network interfaces being connected to a same level 2 (L2) network. The method includes detecting at least two network interface cards (NICs) of the MN that are connected to the same L2 network by at least one of an external device and the MN. A handover decision is made to hand-off a data flow of the MN from a first of the at least two NICs to a second of the at least two NICs. L2 information about the MN in one or more related network entities connected to the same L2 network is updated so as to perform seamless handover without changing an address on level 3 (L3) or higher levels.

Abstract: A system for calibrating a closed power control loop includes an adder configured to inject a test signal into an adjustable element, a first peak detector configured to determine an amplitude of the injected test signal, a second peak detector configured to determine an amplitude of a return test signal, a comparator configured to determine the difference between the injected test signal and the return test signal, and a calibration engine configured to adjust the adjustable element so that the return test signal is offset from the injected test signal by a predetermined amount.

Abstract: A radio communication device in which the output transmission signal of a high-frequency power amplifying part is sent out to an antenna via a circulator, a high-frequency signal reflected from the antenna is transferred via the circulator to a rectifying part to obtain a direct current power, and the direct current power is supplied to a power amplifying part or another constituent part in the radio communication device as an aid to the power supply from a power supply unit.

Abstract: A radio signal detector includes first and second detector circuits. The first detector circuit has a higher detection sensitivity to detect a radio signal earlier than the second detector circuit. The second detector circuit has a lower detection sensitivity to detect the radio signal accurately. When the second detector circuit detects the radio signal, it starts up a microcomputer. When the first detector circuit detects the radio signal, a time counter starts to count time. After being started up, the microcomputer acquires a time difference between the radio signal detection by the first detector circuit and the start-up. The microcomputer determines time of radio signal transmission by a radio signal transmitter device based on the determined time difference, and outputs control information after an elapse of a predetermined time.

Abstract: A power amplifier includes a baseband modulator configured to receive a baseband amplitude component and generate a baseband modulated pulse string, an oscillator configured to receive a baseband phase component and generate phase modulated complex carrier signals, a complex up-converter configured to receive and mix the baseband modulated pulse string with the phase modulated complex carrier signals into mixed product signals, and two or more switched mode power amplifiers coupled to the complex up-converter, configured to amplify and switch the mixed product signals at the carrier frequency. The power amplifier further comprises complex filters individually coupled to one of the switch mode power amplifiers, configured to suppress image components in the amplified and switched mixed product signals, and a power combiner coupled to the two or more complex filters, configured to combine the real component of the complex filtered and amplified mixed product signals to generate an RF transmission signal.

Abstract: An IC includes a microphone interface, a speaker interface, a baseband processing module, and RF section, a processing module, an on-chip to off-chip connector structure, and a digital audio switching module coupled to: provide the inbound voice signal from the processing module to the handheld speaker interface when the IC is in a remote mode; provide the outbound voice signal from the handheld microphone interface to the processing module when the IC is in the remote mode; provide the inbound voice signal from the processing module to the on-chip to off-chip connector structure when the IC is in a docked mode; and provide the outbound voice signal from the on-chip to off-chip connector structure to the processing module when the IC is in the docked mode.

Abstract: In a radio communication station having N antennas an antenna diversity system and a gain controllable amplifier the gain of the gain controllable amplifier is set by using a first antenna, the signal levels of signals received at the antennas is measured, a group of antennas is determined having a signal level which exceeds the signal level of the first antenna by no more than a predetermined value (X), and out of said group of antennas the antenna with the highest signal level is selected out or the first antenna is selected out if said group is empty.

Abstract: A wireless network (20) participates in radio frequency communication with plural wireless terminals (30). The network (20) comprises plural transmitters (40); a precoder value processor (42) configured to develop a set of precoder values; and a precoder (44) which uses the precoder values for coding the signals transmitted from the plural transmitters. The precoder value processor (42) is configured to develop a set of frequency-independent, linear precoder values for use in precoding signals transmitted from the plural transmitters (30). Each vector of the set is associated with one wireless terminal (30). The set of precoder values is determined such that a set of target average signal to interference noise (SINR) ratios is achieved by the plural wireless terminals with a predetermined total transmit power. Preferably, the predetermined total transmit power is minimum total transmit power.

Abstract: A method of transmitting data between first and second network entities in a communications network, the method including, transmitting from the first network entity an establishment message providing a first indication which indicates whether the first network entity is capable of handling extended messages, receiving the message at the second network entity and returning to the first network entity an establishment response which provides the first indication in respect of the second network entity, and transmitting a data message from the first network entity to the second network entity, the data message selectively being an extended message in dependence on the first indication received in the response message, the data message further providing a second indication which indicates whether or not the data message is an extended message.

Abstract: In a wireless communication system (10), when a direct link mode is to be canceled, a station (200) generates a confirmation packet for confirming an unused band of the wireless communication system (10) and transmits the confirmation packet to an access point (100). At the access point (100), a band management part (130) determines the unused band, and a packet generating part (112) generates a response packet indicative of the unused band, which is then transmitted to the station (200). The station (200) determines, based on the unused band indicated by the response packet, whether the direct link mode should be canceled, and transmits a cancellation request packet to the access point (100) if the unused band is sufficient. At the access point (100), the direct link mode is switched to a normal mode for cancellation in response to the cancellation request packet.

Abstract: A remote battery replacement notification system (10) for a communication system includes a subscriber unit (12) having a battery (14). An operational support system (16) is in communication with the subscriber unit (12). The operational support system (16) periodically polls the subscriber unit (12). A compact service node (18) is in communication with the subscriber unit (12). The compact service node (18) sends a replace battery notification to the subscriber unit (12) when a replace battery message is received from the operational support system (16).

Abstract: A high linearity mixer circuit includes a commutation network comprising four switches to provide an electrical coupling between a first pair of circuit nodes and a second pair of circuit nodes, whereas the coupling has two states and is controlled by a pair of complementary logical signals. The mixer circuit further comprises a first pair of current-sourcing devices coupled to the first pair of circuit nodes and a second pair of current-sourcing devices coupled to the second pair of circuit nodes. The mixer circuit further includes a pair of capacitors to provide AC coupling, either between the first pair of circuit nodes and a first external circuit, or between the second pair of circuit nodes and a second external circuit.