Abstract: An apparatus linearizing and technique for linearizing a nonlinear power amplifier used in transmitters of systems for digital wireless communications. Linearization of the nonlinear amplifier is achieved by adding additional signals generated from a specification-given input data stream to the output of the nonlinear power amplifier. The invention allows use of nonlinear power amplifier, which typically enjoys a lower current consumption than that of a linear power amplifier, thus increasing the time between batteries recharges (for user transmitter equipment) and/or reducing the overall size, electric bill expenses, and cooling requirements (for network transmitter equipment). Input data, generated by a given digital wireless standard, is raised to a mathematical power by a required number and converted to RF of a transmitted signal frequency. Then all obtained RF waveforms are added with the same amplitude and the opposite phase to the spectrum of sidelobes generated by nonlinearity of a power amplifier.

Abstract: A apparatus linearizing and technique for linearizing a non-linear power amplifier used in a transmitter of, e.g., a TDMA mobile wireless telephone. Linearization of the non-linear amplifier by changing the shape of the input signal is performed when the input signal level is high, thus increasing efficiency or reducing power consumption at that time, albeit at the cost of increased inter-symbol interference (ISI). However, since the input signals at that time are at a high level, the increased ISI can be tolerated and adjacent symbols can still be distinguished from one another. The invention allows use of a non-linear power amplifier which typically enjoys a lower current consumption than that of a linear power amplifier, thus increasing the time between battery recharges and/or reducing the overall size of the wireless telephone device. The power amplifier is operated in a linear mode when transmitted power is low, thus allowing differentiation between adjacent symbols (i.e., improvement of ISI).

Abstract: A power level determination device provides an output voltage usable as a specific reference power level corresponding to each RF input power level. The device includes a peak detector, which detects a pulse-type signal at its input and provides a non-pulse-type signal at its output. N comparators are provided, where N is an integer. Each of the N comparators has an output, a first input coupled to the output of the peak detector, and a second input coupled to a respectively different threshold voltage. The first one of the N comparators has a maximum threshold voltage. The threshold voltages decrease monotonically from No. 1 to No. N. N exclusive-OR components are provided. A first one of the N exclusive-OR components is coupled to ground and to the output of a first one of the N comparators.

Abstract: A booster for amplifying the signal of a mobile unit of a cellular telephone system. The booster includes a level determination device which produces a reference level based on a power level of a signal received from the mobile unit. The level determination device includes a step voltage circuit which produces a step voltage based on the power level of the signal received from the mobile unit. The step voltage is supplied to a resulting voltage circuit which produces a resulting voltage based on the step voltage, the resulting voltage suitably providing a reference level for the booster.

Abstract: In a wireless communications system, an RF booster provided intermediate an antenna device for receiving RF signals and a receiver device for providing a predetermined amount of gain to said received RF signals and converting said RF signals to audio frequency signals, the RF booster comprising a first amplifier device for receiving input signals from the antenna via a first cable connecting device, the first low noise amplifier providing a first gain equal to the predetermined amount of gain of the receiver device; a second amplifier device connected in series with the first amplifier device, the second amplifier device connected via a second cable connecting device to the receiver device and providing a second amount of gain of a value sufficient to compensate for signal loss provided by the first and second cable means; and a switch element capable of switching out the first gain of the first amplifier device, the switch element controlled by a control signal in accordance with a sensed level of received i