Mediatek Corporation

Other

Chia-Sheng Peng

Sheng-Hong Yan

Chien-Wei Kuan

Chen-Yen Ho

Paul Cheng Po Liang

Da-Wei Sung

Tsung-Lin Lee

Chiou-Wei Tsai

Yen-Liang Chen

Wei-Cheng Liu

Shih-Mei Lin

Che-Hao Meng

Kuei-Ann Wen

Yu-Ting Liu

Tso-Min Chen

Che-Yu Chiang

Chung-Hsien Tsai

Ting-Ming Yang

Yuan-Shin Chuang

A communication receiver includes a first signal processing circuit and a second signal processing circuit. The first signal processing circuit includes a first feedforward equalizer and a decision circuit. The first feedforward equalizer processes a received signal to generate a first equalized signal. The decision circuit performs hard decision upon the first equalized signal to generate a first symbol decision signal. The second signal processing circuit includes a second feedforward equalizer, a decision feedforward equalizer, and a first decision feedback equalizer. The second feedforward equalizer processes the first equalized signal to generate a second equalized signal. The decision feedforward equalizer processes the first symbol decision signal to generate a third equalized signal. The first decision feedback equalizer generates a second symbol decision signal according to the second equalized signal and the third equalized signal.

Communication receiver using multi-stage channel equalization and associated method

A circuit module includes a power amplifier, a switch, and a bypass capacitor. The power amplifier has a signal input node coupled to an input signal, a signal output node to generate an output signal, and a power input node coupled to a supply output signal of a supply modulator. The switch is coupled between the power input node of the power amplifier and the bypass capacitor. The bypass capacitor is an equivalently removable bypass capacitor coupled between the switch and a ground level.

Circuit module having dual-mode wideband power amplifier architecture

Apparatus and methods are provided to calibrate a closed-loop envelop tracking system for a power amplifier of a wireless transmitter using standardized modulation signals. In one novel aspect, a closed-loop adaptive method is used to track changes in PA nonlinearity due to environmental or circuitry changes during operating condition using standardized modulation signals. In one embodiment, the PA supply voltage compensation lookup table (LUT) and/or the phase compensation LUT is updated during normal operation to sustain good linearity and efficiency performance. In another novel aspect, the PA target response is adjusted in response to changes in PA-related system configuration, such as changes in PA bias settings, and/or indicators measured from the transmitter such as changes in impedance or temperature changes for the RF module or the PA module. The PA supply voltage compensation LUT and/or the phase LUT is updated accordingly upon adjustment of the PA target response.

Envelope tracking (ET) closed-loop on-the-fly calibration

Provided is a power supply circuit for a wireless mobile device having a plurality of power amplification components. The power supply circuit includes: a first DC-DC converter, for providing at least one constant output voltage (which is provided to the power amplification components) and/or at least one DC intermediate voltage; a second DC-DC converter, for providing a DC component of at least one time-varying output voltage; and at least one linear amplifier. When the at least one linear amplifier receives the at least one DC intermediate voltage from the first DC-DC converter, the at least one linear amplifier provides at least one AC component of the at least one time-varying output voltage. The DC component and the at least one AC component of the at least one time-varying output voltage are combined into the at least one time-varying output voltage and provided to the power amplification components.

Power supply circuit of wireless mobile device

A communication unit comprises a decimator configured to sample a variable control signal and output a reduced bandwidth variable control signal; and a multi-level power supply, MLPS, comprising an input and an output, wherein the input is coupled to the decimator and configured to receive the reduced bandwidth variable control signal and, in response thereto, the output delivers multi-level output voltages to supply a power amplifier, PA, module.

Communication units and methods for power supply control

Techniques and examples pertaining to variation calibration for envelope tracking on chip are described. Envelope tracking (ET) statistics among multiple wireless-capable mobile devices (e.g., smartphones) may be collected in laboratory. Optimal ET parameters may be determined based on ET statistics. An ET setting file may be generated for ET factory calibration. In production lines, the ET setting file may be loaded into each mobile device for ET factory calibration.

Variation calibration for envelope tracking on chip

A communication unit comprises a radio frequency, RF, transmitter comprising: a power amplifier, PA, module; an envelope tracking system operably coupled to the PA module and arranged to variably control a supply voltage for the PA module; and a load control system operably coupled to an output of the PA module and arranged to control a power amplifier output load.

Methods and apparatus for envelope tracking system

A novel and simplified orthogonal frequency division multiplexing (OFDM) equalizer uses a coordinate rotation digital computer (CORDIC) to convert the estimated channel effects from rectangular coordinate to polar coordinate and to compensate the phase error with the same CORDIC circuit of synchronization. The OFDM equalizer comprises: a fast Fourier transformer (FFT); a channel estimation circuit; a coordinate translator, comprising a CORDIC circuit, to translate the channel estimation value into a polar coordinate value; a pilot extractor to extract pilot signals and to track minor phase offsets of the received signal to synchronize phase of said received signal; a phase rotator to compensate phase of the received signal according to the channel estimation value and the phase tracking estimation value, to generate the real value and imaginary value of the phase compensated signal; and an amplitude adjustment circuit. The coordinate translator and the phase rotator use the same CORDIC circuit.

Growing community of inventors

Taichung, Taiwan

Chia-Sheng Peng