Abstract: In order to rapidly control the gains of a plurality of variable gain amplifiers VGAs, each of gain control circuits is configured to determine a gain to be set therein, based on gain control information received from other gain control circuits existing in its preceding stage or stages and the signal level detected by a level detector circuit connected thereto. By carrying out such gain control, a total application gain is stabilized more quickly by gain control. Therefore, even in receiving systems that the preparation period for reception is very short, desired gain control is achieved within this period and stable data reception can be performed.

Abstract: In a diversity receiver comprising an AGC section for controlling the gain of a tuner, an equalizer equalizes an outputted signal from a fast Fourier transformer. A reliability calculator calculates the reliability value of each of carriers by an equalized pilot signal obtained from the equalizer. A reliability value corrector corrects the reliability value by outputted information from the AGC section. A carrier selecting/combining section performs one of selecting and weighting combining for the carrier in a branch in accordance with the corrected reliability value. When a Viterbi decoder is provided, the Viterbi decoder weights an output from the carrier selecting/combining section with a new reliability value to perform maximum likelihood decoding. It is possible to prevent a reliability value which does not reflect an actually received power from being calculated as a result of increasing a power by an AGC in spatial diversity for every OFDM or FDM demodulated carrier.

Abstract: Conventional digital broadcast receiving tuners normally perform identical operations regardless of whether the actual level of a signal received within a receivable frequency band remains flat or irregular, and this makes it impossible to obtain optimal performance characteristics according to the level of the received signal.

Abstract: In order to provide a variable gain amplifier of enhanced linearity and wide variable gain range, an AM-modulated signal reception circuit in which the noise of an input portion is reduced so as to improve the follow-up characteristic of an AGC circuit, and an AM-modulated signal detection circuit which produces an output precisely corresponding to a peak value envelope, the variable gain amplifier comprises a differential input amplifier which includes transistors T1 and T2 (in FIG. 8) constituting a differential pair, and a constant current circuit Is operating as an absorption current circuit of the transistors T1 and T2, and a variable impedance which is connected between the sources of the respective transistors T1 and T2, wherein the gain of the differential input amplifier is made variable by variably controlling the value of the variable impedance.

Abstract: Provided is an automatic gain controller for obtaining a high a signal-to-noise ratio (SNR), and for reducing power loss by controlling a gain until the gain reaches a maximum value, and a transmitting apparatus and method for use with a mobile communication terminal having the automatic gain controller. The automatic gain controller causes a variation of a gain at a radio frequency (RF) amplifier with respect to the variation of a control voltage to have a larger gradient than a variation of gain at an intermediate frequency (IF) amplifier with respect to the variation of the control voltage, and causes a total gain to have a decreasing gradient in accordance with the control voltage until the total gain reaches its maximum.

Abstract: The invention relates to a device for correcting a receiver signal which is associated with an emission signal transmitted in a distorted transmission system. The emission signal comprises periods which can be determined by analyzing the received signal wherein determined properties are exhibited which are suitable for adjusting the correction. According to one embodiment, the device comprises a component for adjusting the correction based upon an analysis of the received signal and a component for monitoring and enabling the adjusting component when the received signal associated with the transmission signal exhibits certain characteristics.

Abstract: A method includes amplifying the plurality of received signals, generating a plurality of time domain samples of the amplified signals with at least an analog-to-digital converter (ADC), determining at least a candidate power according to root-mean-square (RMS) powers of a first group of symbols received at the receiver antennas, and setting the gain of the amplifier according to a selected candidate power with the processor. The received RMS power for one antenna is determined as the square root of the averaged product of each received symbol and its complex conjugate for all symbols of the first group. The candidate power can be determined considering a subgroup of antennas using an RMS value, an arithmetical mean value, or a geometric mean value of this sub-group.

Abstract: A receiver generates two metrics, one that is used to control the gain of an amplifier and the other that is used to determine the presence of narrowband interference, such as IMD. The two metrics may represent analog-to-digital converter (A/D) saturation and average signal strength, either of which may be used to control gain or to detect the presence of narrowband interference.

Abstract: A transmission weight vector computing unit computes transmission weight vectors. A transmission weight vector correcting unit obtains a corrected transmission weight vector W′(t). A predicted receiving power computing unit computes a predicted receiving power value Y(t). If a difference between the predicted receiving power value Y(t) and a predicted receiving power value in the past Y(t-T) is less than a threshold value, an update unit selects the corrected transmission weight vector W′(t). If, on the other hand, the difference is greater or equal to the threshold value, the update unit selects a corrected weight vector in the past W′(t-xT). If the modulation method is QPSK, a setting unit selects the transmission weight vector W(t). If the modulation method is 16 QAM, the setting unit selects the corrected transmission weight vector W′(t) or W′(t-xT) and outputs it as a final transmission weight vector signal.

Abstract: A system for compensating radio frequency (RF) receiver gain (400) by implementing both automatic gain control (AGC) and digital normalization where the receiver includes at least one front-end configurable gain stage (401) for providing selectable gain to the receiver. An analog-to-digital converter (ADC) (407) for converting an analog input signal from the configurable gain stage (407) to a digital signal. An AGC controller (405) is then used to determine a level of gain of a received input signal and controlling the front-end configurable gain stage (401). A digital normalizer (411) then truncates the digital data from both the ADC (407) and subsequent digital stages for maximizing the dynamic range of the receiver. The invention offers advantages in controlling receiver gain when in crowded band conditions with many potentially interfering signals are present with a desired signal.

Abstract: In a direct conversion receiver, to cancel a DC offset generated in the baseband processing block, negative feedback arrangements comprising a gain control amplifier and a low-pass filter are respectively attached to the I and Q signal branches of the baseband block following mixer outputs. The gain control amplifier in each negative feedback circuit is gain adjusted so that the product G-B of the gain G of a primary gain control amplifier and its own gain B will be constant and thereby the DC offset is cancelled. This DC offset cancellation can be applied in a continuous receiving system with no intermittent time during a receiving operation. Capacitance elements located off-chip can be reduced to those to be used only in the low-pass filters in the negative feedback circuits, whereas many off-chip capacitance elements have been required to be inserted between each stage of gain control amplifiers in conventional baseband chains.

Abstract: An apparatus and method for compensating the gain of an Automatic Gain Controller (AGC) for stabilizing the reception power of discontinuously transmitted packet data in a mobile communication system are disclosed. A compensation controller receives an AGC value from the AGC, sampling the AGC value by a predetermined sample number for a predetermined period, and obtains an AGC compensation gain by comparing a predetermined value with the difference between a sampled AGC value with a reference gain for the predetermined period. A compensator compensates the AGC value with the AGC compensation gain, thereby correcting errors generated in view of the nature of the AGC.

Abstract: A transmission side device combines two independent transmission signals (S1, S2) together to produce two combined signals, i.e., a sum signal (S1+S2) and a difference signal (S1−S2), and transmits the produced signals over two radio wave propagation paths, respectively. After the sum signal and the difference signal are received by the reception side device, the sum signal and the difference signal, as received, are subjected to an AGC control operation and a complex-level multiplication operation with a weighting coefficient based on correlation control, and then separated into two, restored, independent signals.

Abstract: A method and an apparatus for automating gain control of a radio frequency communication system can adapt a radio frequency communication system to an environment where a radio channel characteristic is rapidly or slowly changed. This can be achieved by extracting a maximum absolute value of a reception signal received by a receiver of a radio frequency communication system, determining a gain control value of the reception signal on the basis of the maximum absolute value and a predetermined threshold, and controlling gain of the reception signal according to the determined gain control value.

Abstract: A transmission apparatus of a mobile communication terminal is implemented so that a modem, a gain controller and a power controlling circuit have one loop construction. In the transmission apparatus, an AGC signal of a modem is precisely adjusted according to an internal temperature of the terminal, and the adjusted AGC signal is applied to gain control in real time, so that a consumption amount of battery due to a loss of a current can be remarkably reduced.

Abstract: The invention provides systems, methods, and devices that compensate for temperature, frequency, and sampling effects in a broadband communication device's power measurements. One embodiment of a system includes a thermal device, and an automatic gain control circuit coupled to the thermal device. One method includes the acts of disabling a TOP operation, setting a RF input power, reading an AGC GAIN value, and setting the broadband communications device based on the read AGC value. Furthermore, a broadband communications device according to the invention may operate by disabling a TOP operation, setting a RF input power, reading an AGC GAIN value, and setting the broadband communications device based on the read AGC value.

Abstract: An Automatic Gain Control system (AGC) in which an adder adds a Radio Frequency (RF) signal power of only the low-frequency component of a RF signal and an intermediate-frequency (IF) signal of an output from a variable-gain intermediate-frequency amplifier, which is higher than the frequency of the low-frequency component, and outputs the result to an A/D converter. This construction makes it possible to input power data for the RF stage to a demodulation LSI. The demodulation LSI separates the low-frequency component from the input signal, and by detecting the power of the extracted signal, is able to obtain the output data for the RF signal, and it separates the IF component from the input signal, and by detecting the power of the extracted signal, is able to obtain the output data for the IF signal.

Abstract: An adaptive transmit antenna array having a reduced pilot set is disclosed. The adaptive transmit antenna array utilizes a decision-directed mechanism for the estimation of maximal ratio combining (MRC) weights to be used at a receiver rather than requiring a user-specific pilot to provide estimation information.

Abstract: An automatic gain control circuit that maximizes front-end signal attenuation is disclosed. The automatic gain control circuit comprises a keyed automatic gain control circuit and an intermodulation detector. The intermodulation detector detects signal interference and generates an intermodulation detection flag. The keyed automatic gain control circuit uses the intermodulation detection flag to control front-end signal attenuation. A method for maximizing front-end signal attenuation for the automatic gain control circuit is also disclosed.

Abstract: System and method for reducing distortion in a receiver by adjusting amplifier linearity. A preferred embodiment comprises measuring a received signal's power level and then making an adjustment the linearity of a receiver's amplifier, wherein the amplifier lies within the receiver chain. A second measurement of the received signal power level is made, followed by a calculation of the difference of the signal power levels. If the difference is less than expected, distortion is insignificant and linearity should be reduced to reduce power consumption. If the difference is greater than expected, then distortion is significant and the amplifier's linearity should be increased to reduce distortion. These measurements can be repeated to find an optimal operating point to minimize distortion and power consumption.

Abstract: A radio receiver having an FM band tuner, an AM band tuner, a controller coupled to both said tuners, and a radio data (RD) decoder for providing radio data. The RD decoder is coupled for receiving radio data from at least one of the tuners which is tuned to a radio program. The RD decoder is coupled to the controller for switching the radio receiver from FM band to AM band or vice versa based on radio program frequency correspondence data included in the radio data. The radio receiver is advantageous since it allows for automated cross switching between different frequencies whereon a same radio program is broadcast. This is particularly advantageous if the radio receiver, such as placed in a car, leaves the broadcast coverage area. User intervention is thus obviated.

Abstract: A receiver according to this invention comprises a mixing section (9) for frequency-converting a received high-frequency signal and outputting a base band signal, an amplifying section (10) for amplifying the base band signal; a load resistance (21, 22) provided between the mixing section (9) and the amplifying section (10), and a control section (3) for controlling an input signal level of the amplifying section (10) by changing a resistance value of the load resistance, thereby broadening a linear range of the receiver by simple structure and simple control.

Abstract: In a radio circuit (299) that forwards a signal pair (I,Q) by first (291, I) and second (292, Q) channels, by converting the signal pair (I,Q) from a digital form (ID, QD) to an analog form (IA, QA), a gain controller (200) monitors differences between the overall gains (GI, GQ) in the channels and corrects a gain imbalance by feeding back a gain determining control signal (W) to one of the channels. The gain controller (200) has digital comparators (221-224) at the inputs (281, 282) of the channels and analog comparators at the outputs (283, 284) of the channels. Intrinsic offsets of the analog comparators are determined and compensated by subtracting corresponding offsets from the digital comparators.

Abstract: A method of processing radio signals received via multiple antennas in a radio receiver having at least one of the following: at least two antennas, each antenna delivering in use an antenna signal; at least two elements of an antenna array, each antenna element delivering an antenna signal; at least two antenna arrays each having a plurality of antenna elements, each antenna array delivering an antenna signal; the antenna signals being combined to deliver a combined signal, wherein for each antenna signal an iterative channel estimation is performed to control the combining process of the antenna signals. Advantages of the invention are improvement of error rate performance of multiple antenna radio receivers, because the antenna gain can be enhanced due to reducing the combining losses.

Abstract: An analog/digital gain control device avoid some of the requirements associated with the nature of a closed-loop AGC circuits and which meets the remaining requirements without much difficulty uses an analog to digital conversion method that increases the number of effective ADC bits by compressing the baseband input analog signal using a logarithmic circuit. After the compressed analog signal is converted into a digital signal, a digital anti-log process or look-up table (LUT) is used to expand the digital signal back to the original linear scale. The word size of the output of the anti-log process is larger than the input word size due to the nature of the anti-log function. To reduce the word size of the digital signal an open loop normalization technique can be applied.

Abstract: A temperature compensation circuit comprises a signal source to output a first signal corresponding to a temperature change of an ambient temperature to a predetermined temperature, and a multiplier to multiply an external gain control signal and the first signal and output a second signal proportional to the temperature change and the first signal to a variable gain amplifier to perform the temperature compensation with respect to the variable gain amplifier.

Abstract: A gain control part controls a gain varying part such that the gain of a received signal corresponds to the input level of the received signal in a first control mode and controls the gain varying part so as to fix the gain of the received signal in a second control mode. A setting part sets the gain control part in the first control mode in a communication state and sets the gain control part in the second control mode in a standby mode.

Abstract: A processing unit with balanced outputs transfers a received digital signal to an amplification unit with balanced inputs and outputs. A control unit enables or disables the processing and amplification units in response to a power up/power down signal. To prevent disturbances due to power up/power down transients from appearing in a speaker connected between the outputs of the amplification unit, switches are provided between the outputs of the processing unit and the inputs of the amplification unit. A delay circuit generates according to a predetermined timing program enabling/disabling control signals for the processing and amplification units, and generates control signals for the switches.

Abstract: An automatic gain control (AGC) system (100) for a controlled gain receiver (1101) includes a magnitude generator (160) and a gain corrector (170). The magnitude generator (160) generates a binary voltage squared signal (165) having a binary value that is directly proportional to a recovered signal power of an intercepted signal (113). The gain corrector (170) determines an adjustment of a gain control value (195) as a multiple of increments that are approximately 3 decibel (dB), by shifting (475, 445) a reference threshold by one or more bits and comparing (485, 455) the shifted reference threshold to the binary voltage squared signal. An initial setting of a state of a step attenuator (114) during a track mode (172) is determined during a warm up mode (171) by comparing the binary voltage squared signal (165) to two different thresholds (245, 255). A filter (162) accommodates a variety of bandwidths and symbol rates by settings of an accumulator (505) and scaler (510) that are included in the filter (162).

Abstract: The invention relates to gain control for an amplifier for received radio signals by means of an automatic gain control signal (c). A down converter (103) produces signal components (I; Q) from received radio frequency signals (RF). The signal components (I; Q) are amplified in a respective amplifier (104; 105), low pass filtered (106; 107) and further amplified (108; 109). Then, the resulting signal components (IP-LP; Q−LP) are digitised in A/D-converters (110; 111 ) for further processing in a digital signal processor (112). The resulting signal components (IP-LP; QP-LP) are also fed to a respective signal level detector (113; 114) whose output signals ([I]; [Q]) are combined (115) into a combined signal (V&Sgr;). This signal (V&Sgr;) is forwarded to a gain control unti (116), which produces the automatic gain control signal (c).

Abstract: A first AGC voltage and a second AGC voltage are taken from the final stage of a radio-frequency circuit and the output side of a bandpass filter, respectively, and the gain of the radio-frequency circuit is controlled on the basis of the two AGC voltages. The pass-band width of the bandpass filter is approximately two times greater than the frequency interval of FM broadcast signals. The second AGC voltage is set higher than the first AGC voltage in the pass-band of the bandpass filter.

Abstract: A device for linear transmitter 150 with improved loop gain stabilization. The linear transmitter 150 includes a main amplifier loop 178 and an auxiliary loop 176. The device includes an adjustable driver 159, connected within the main amplifier feedback loop 178 and further connected to the auxiliary loop 176. The adjustable driver 159 receives an input signal from main amplifier feedback loop 178, amplifies it in accordance with a gain control signal received from the auxiliary loop 176 and provides the amplified signal to main amplifier feedback loop 178.

Abstract: In accordance with the present invention, a receiver circuit and a method of controlling voltage pulses, thereby improving the performance of the receiver are provided. The receiver circuit includes a switch for blocking high voltages and for converting voltage signals to current signals. The switch includes first and second signal terminals and a control terminal. The switch exhibits an ON resistance when closed, wherein the ON resistance is controlled by an electric value at the control terminal. The receiver circuit also includes a control circuit coupled to the switch for controlling the ON resistance of the switch in closed mode. The first switch signal terminal is coupled to an output of a transducer and the second switch signal terminal is coupled to an input of a low-noise amplifier circuit. The switch is a transmit/receive switch which is open during a transmission time interval and closed during a reception time interval.

Abstract: A radio back-end integrated circuit that includes a blanking switch having a signal input which receives an IF signal, a control input, and a signal output. Also included is a demodulator having an input coupled to the output of the blanking switch, and an output. The radio back-end also has a sample and hold switch having a signal input coupled to the output of the demodulator, a control input, and an output. Combined with the switch is a noise impulse detector having an input coupled to the IF signal and an output coupled to the control inputs of the blanking switch and the sample and hold switch. A sample and hold/de-emphasis circuit has an input coupled to the output of the sample and hold switch, and an output. The sample and hold/de-emphasis circuit has a high input impedance amplifier, a resistor, and only one capacitor.

Abstract: A video signal processing apparatus capable of improving signal level while reducing noise component no matter a video signal of what illuminance is input is provided, which apparatus includes a video signal amplifying circuit amplifying an input video signal and outputting a video signal of a predetermined image size in accordance with a gain control coefficient, a frame addition circuit connected to the video signal amplifying circuit for adding outputs of the video signal amplifying circuit by a predetermined number of frames, a first signal level detecting circuit connected to the video signal amplifying circuit and calculating the gain control coefficient and a multiplication coefficient in accordance with an output of the video signal amplifying circuit, and a first multiplier connected to the frame addition circuit and the first signal level detecting circuit and receiving as inputs an output of the frame addition circuit and the multiplication coefficient.

Abstract: A receiver is adaptively calibrated by using a coherent reference signal. The reference signal is selected to be offset from a center frequency of the calibration signal such that the resultant product is offset from baseband by some small amount. The resultant product is used to determine a next value of the calibration parameters.

Abstract: A system (10) and method (100) for digitizing a complete band of RF channels to allow simultaneous processing of more than one channel. Multiple tunable bandpass filters (14) are used for the particular channels to be processed. The filter outputs are combined (16) to form one signal for digitization (18). In another embodiment, an undesired signal is rejected (112) to provide more available power for a reception of a desired signal.

Abstract: A communications device includes a frequency conversion circuit and a control circuit. An antenna receives a radio signal at a first frequency and converts it into a radio frequency (RF) signal of the first frequency. The frequency conversion circuit is associated with the antenna and configured to convert the RF signal into a first signal component and a second signal component. The first and second signal components occupy a baseband. The control circuit has first ports connected to the frequency conversion circuit to receive the first and second signal components and second ports connected to a processor circuit to output amplified first and second signal components, and separate channels for the first and second signal components existing between the first and second ports. Each channel comprises an amplifier and a feedback loop configured to control the amplifier as a function of a reference signal and a control signal derived from the RF signal.

Abstract: An apparatus for providing automatic gain control for use in a satellite terminal of a satellite communication system capable of transmitting a plurality of different modes of data. The apparatus includes a demodulator circuit having an analog to digital converter; a first variable attenuator having an attenuation value set on the basis of a measured power level of a predetermined data signal; and a second variable attenuator having an attenuation value set on the basis of the mode of data being received by the satellite terminal, where each of the data modes have a corresponding predetermined attenuation value associated therewith which is utilized as the attenuation value of the second variable attenuator when the satellite terminal receives the data mode.

Abstract: In response to the base station receiving a received signal, the received signal having a first spread-spectrum signal and an interfering signal. An automatic gain control (AGC) circuit generates an AGC-output signal which is despread by a despreader and then processed as a received-power level. A power command signal is generated using a threshold test and the received-power level.

Abstract: Base stations have a plurality of antenna devices and a radio communicating zone, respectively. Each base station transmits respective information signals multiplied with a first complex weight from one antenna device and multiplied with a second complex weight from the other antenna device, when the mobile station is within each of the communication zones. The base stations renew the first and the second complex weights based on the direction of the mobile station. One of the base stations determines the initial values of its first and second complex weights based on a direction information of the mobile station obtained when the mobile station was in the zone of the other base station, upon moving from one zone to the other zone.

Abstract: An IC for communication includes a single oscillating circuit, which is capable of flexibly dealing with the change of data rate or data processing load, and is produced at a low cost and consumes low electric power. In the IC for communication, a frequency multiplying circuit(61) is inserted between the output of an oscillating circuit(1) and a micro-controller circuit(69), or a frequency dividing circuit(2) is inserted between the oscillating circuit(1) and a data receiving circuit(3). A receiving address is stored in a dual port RAM(16). Further, by controlling a receiving frequency of synchronous codes, battery saving efficiency is increased.

Abstract: A method of adjusting transmit power in a CDMA portable phone to maintain adjacent channel power rejection (ACPR) passing margin includes the steps of amplifying a first radio frequency (RF) signal according to a first gain to produce a second RF signal, and amplifying the second RF signal according to a second gain to produce a third RF signal. A desired power level of the third RF signal is determined and a new gain value is computed from the desired power level. The first gain value is adjusted to the new value. A system for adjusting transmit power in a CDMA portable phone to maintain adjacent channel power rejection (ACPR) passing margin includes an automatic gain control (AGC) amplifier having an AGC input terminal, an AGC output terminal, and a control signal input terminal. The system also includes a power amplifier (PA) having a PA input terminal and a PA output terminal, wherein the PA input terminal is connected to the AGC output terminal.

Abstract: A gain control circuit for a telephone, the circuit comprising a signal strength calculator for calculating the strength of a signal; a gain controller adapted to modify the strength of the signal in accordance with a predetermined criterion based on the strength of the signal calculated by the signal strength calculator.

Abstract: The invention relates to a method of automatic gain control (AGC) in a base station of a cellular radio network and to a network part in a cellular radio network. The method comprises receiving at least one random access burst transmitted by a subscriber terminal of the cellular radio network on a random access channel. Then the received power of the random access burst is measured, followed by generating subscriber terminal-specific AGC data on the basis of the received power of at least one random access burst. Then, subscriber terminal-specific AGC data is stored. Next, a normal burst transmitted by the subscriber terminal on a stand-alone dedicated control channel is received, and the gain of the normal burst received is controlled by the subscriber terminal-specific AGC data. Finally, the controlled normal burst is subjected to analog-to-digital conversion.

Abstract: A DC offset correction method and apparatus. In a DC offset correction loop (100), a DC offset is corrected using a binary search routine or any other digital or analog DC offset correction technique. In this binary search routine, the sign of the offset (138) is used to control a direction in which a digital to analog converter (DAC) (166) is stepped until the least significant bit of the DAC is set. The process is enhanced by opening up the bandwidth of the baseband filters (130) to permit the binary search to be clocked (180) at a higher clock rate. After the correction is established, the filters (130) are reset to normal operating conditions.

Abstract: A cellular base station transmitter/receiver system is provided which combines adaptive array processing, for the uplink RF signals, and fixed beam switching, for the downlink RF signals. An example of the configuration employs at least four antenna ports, with all four ports being used to provide uplink RF signals to a receiver processor, two being used to supply narrow beam uplink signals and two being used to supply wide beam uplink signals. Two of the four ports are used to provide beam switched narrow beam downlink RF signals.

Abstract: Device (200; 500) for minimizing the quantization noise in conversion between analogue and digital form of a multi-carrier signal comprising an AC component (VAC) with a particular RMS value (VRMS). The device comprises means (230; 530) for converting between analogue and digital form with a limited number (b) of bits within a quantization range (±VQR), means (215,235,245,255; 520) for minimizing the noise by creating an ideal ratio (VQR/VRMS) between the quantization range and the RMS value of the AC component, and means for reducing unwanted DC components in the signal and centering the signal by the wanted DC components being placed in the centre of the quantization range.

Abstract: An automatic gain controller for reducing the required code size and processing burden of a digital signal processor (DSP) chip. The automatic gain controller includes an automatic gain control (AGC) amplifier and an A/D converter for converting an analog signal output from the AGC amplifier to a digital signal. A power estimator estimates a power of a signal input from the A/D converter. An infinite impulse response (IIR) filter filters the power output from the power estimator to attenuate noises and interferences. A comparator receives the filtered power output from the filter and generates an AGC control gain. A dB-to-D/A input converter converts the AGC control gain output from the comparator to a D/A input signal. A D/A converter converts the D/A input signal output from the dB-to-D/A input converter to an analog AGC control signal and provides the AGC control signal to the AGC amplifier.

Abstract: Signal delay and combining techniques are used with multipath signals to provide signal diversity gain within CDMA over-the-air repeater and low noise amplifier systems. An incoming signal from a remote user is typically processed through two processing paths, wherein one path adds a delay to the processed signal. The two signal paths are then combined and filtered through a sharp band pass filter, preferably a SAW filter. In an over the air repeater, the filtered signal is retransmitted towards a CDMA rake receiver at a base station, which can process the multipath signal to produce a clean signal representation. In a low noise amplifier, the filtered signal is transferred directly into a base station or repeater. The use of SAW filters protect the latter stages of the low noise amplifier, and also protect the base station from out-of-band signal interference.