This disclosure provides a method for gain control in a wireless receiver. The wireless receiver comprises a first receiver chain adapted to receive a first signal in a first frequency range, a second receiver chain adapted to receive a second signal in a second frequency range, and a common amplifier module operatively connected to the first receiver chain and the second receiver chain. The method comprises determining a first target gain level for a first path comprising the common amplifier module and the first receiver chain, and determining a second target gain level for a second path comprising the common amplifier module and the second receiver chain. The method comprises setting a gain GA of the common amplifier module and a gain GRx1 in the first receiver chain and a gain GRx2 in the second receiver chain based on the first target gain level and the second target gain level.

One embodiment is directed to controlling a gain for a receive signal path for receiving wireless signals. The following are repeatedly performed: determining an estimate of the total noise and interference in a received signal and determining a gain value for the receive signal path based on the estimate of the total noise and interference in order to maintain the digital data at a digital set point for a signal-to-interference-plus-noise-ratio (SINR) decoded with a highest modulation and coding scheme specified for the wireless channel. Another embodiment is directed to determining a received signal strength of the signals received at the receive signal path and determining a gain value for the receive signal path based on the received signal strength that maintains the digital data at a digital set point for a SINR sufficient to decode the MCS specified for the wireless channel.

Embodiments of methods and systems for gain control in a communications device are described. In an embodiment, a method for gain control in a communications device involves detecting a change in an amplification gain that is applied to an analog signal in the communications device and compensating for the change in the amplification gain by manipulating an amplitude of a digital signal that is converted from the analog signal. Other embodiments are also described.

An apparatus includes an amplifier and a gain control circuit. The amplifier may be configured to provide multiple gain steps. The gain control circuit may be configured to provide fast and precise changes between the multiple gain steps of the amplifier. The gain control circuit may be further configured to change an impedance of the amplifier to switch between the gain steps. The gain control circuit may be further configured to compensate for changes in frequency response related to changing the impedance. The gain control circuit may be further configured to inject a complementary charge to an input of the amplifier to correct a bias voltage deviation and a transient caused by the gain control circuit.

A communication system includes a modulator configured to generate a modulated signal responsive to at least a data signal, and a demodulator configured to demodulate the modulated signal responsive to a first carrier signal. The demodulator includes a filter configured to generate a filtered first signal based on a first signal, and a gain adjusting circuit coupled to the filter. The first signal is based on the first carrier signal and modulated signal. The filter has a gain controlled by a set of control signals. The gain adjusting circuit is configured to adjust the gain of the filter, and to generate the set of control signals based on a voltage of the filtered first signal and a voltage of the first signal. The gain adjusting circuit includes a first peak detector coupled to the filter, and configured to detect a peak value of the voltage of the filtered first signal.

A receiving system includes a controller that selectively activates one or more of a plurality of paths between an input of a first multiplexer and an output of a second multiplexer. The receiving system includes a plurality of bandpass filters, each one of the bandpass filters being disposed along a corresponding one of the plurality of paths and configured to filter a signal received at the bandpass filter to a respective frequency band. The receiving system also includes a plurality of variable-gain amplifiers (VGAs), each one of the plurality of VGAs disposed along a corresponding one of the plurality of paths and configured to amplify a signal received at the VGA with a gain controlled by an amplifier control signal received from the controller. At least one, but not all, of the VGAs is a fixed-gain amplifier with a bypass switch to selectively bypass the fixed-gain amplifier.

A system and a method for calibrating an output signal of an antenna is disclosed. In one aspect, an apparatus includes a first digital adder configured to generate a gain offset by at least adding gain calibration data from non-volatile memory and gain command data from static memory. The apparatus further includes an amplitude gain circuit configured to modify, based at least in part on the gain offset, an amplitude of a first output signal of a first antenna. The modified amplitude of the first output signal is provided to enable pre-calibration of the first output signal. The apparatus further includes a power detector configured to measure an output power of the first output signal. The apparatus further includes at least one processor configured to generate a difference between the measured and expected output power, and adjust gain command data in response to the generated difference.

A wireless receiver including multiple amplifiers coupled in series for amplifying a signal being received, at least one detector that provides a strength indication of the signal being received, multiple AGC schedules each determining a gain reduction schedule for the amplifiers, an AGC schedule selector that selects one of the AGC schedules based on a schedule select input, and an AGC controller that adjusts a gain of at least one of the amplifiers according to a selected AGC schedule based on the strength indication of the signal being received. The AGC schedules may include a first AGC schedule configured for improved SNR performance and a second AGC schedule configured for improved distortion performance. The second AGC schedule may be selected for improved distortion performance when a strong distorting blocker signal is present, and otherwise the first AGC schedule may be selected for better SNR performance.

This technology relates to a single-phase differential conversion circuit for improving the linearity of input/output characteristics, a signal processing method for use with the circuit, and a reception apparatus. The single-phase differential conversion circuit includes a first source-grounded amplifier and a second source-grounded amplifier. Each of the amplifiers includes a transconductance amplifier section including a transistor for converting an AC component of input potential to a current, a diode load section including a transistor in a diode connection configured as a first load, and a large-signal distortion compensation circuit configured as a second load connected in parallel with the first load. The transistors of the first source-grounded amplifier are each a P-type MOS transistor, and the transistors of the second source-grounded amplifier are each an N-type MOS transistor. This technology is applied advantageously to a reception apparatus for receiving TV signals, for example.

A system and a method for calibrating an output signal of an antenna is disclosed. In one aspect, an apparatus includes a first digital adder configured to generate a gain offset by at least adding gain calibration data from non-volatile memory and gain command data from static memory. The apparatus further includes an amplitude gain circuit configured to modify, based at least in part on the gain offset, an amplitude of a first output signal of a first antenna. The modified amplitude of the first output signal is provided to enable pre-calibration of the first output signal. The apparatus further includes a power detector configured to measure an output power of the first output signal. The apparatus further includes at least one processor configured to generate a difference between the measured and expected output power, and adjust gain command data in response to the generated difference.