Spreadtrum Communications USA Inc.

Quorum Systems, Inc.

Spreadtrum Communications Corporation

Lon Christensen

Lawrence Jarrett Malone

David Ryan Haub

Zebin Wang

A self-calibrating transceiver includes a baseband processor, a receiver chain comprising an amplifier and a digital front end (DFE), and a transmitter chain, and a calibration control state machine. The state machine stores amplifier gain steps and is in communication with the transmitter chain, the receiver chain, and the baseband processor. The state machine can set a receiver chain frequency at a predefined frequency and set a transmitter chain frequency to be offset relative to the receiver chain frequency. For each of the amplifier gain steps, the state machine can set a gain of the receiver chain and set a power of the transmitter chain. The baseband processor can measure an RSSI and transmit the measured RSSI to the state machine. The state machine can determine a digital gain compensation value based on the one or more measured RSSIs and apply the determined digital gain compensation value.

Transceiver system supporting receiver self calibration and methods of performing the same

A self-calibrating transceiver includes a transmitter chain, a receiver chain, a base band processor, and a calibration control state machine. The state machine is in electrical communication with the transmitter chain, the receiver chain, and the base band processor, and is configured for enabling the receiver chain and setting the receiver chain and the transmitter chain to corresponding frequencies. The state machine stores one or more transmitter power and power amplifier gain mode settings, and for each setting, sets the transmitter gain and power amplifier gain mode. The transmitter chain transmits a signal, the receiver chain receives the transmitted signal, and the baseband processor measures a received signal strength indicator (RSSI) of the received signal. The state machine further adjusts the transmitter output power based on the measured RSSI.

Transceiver system supporting transmitter self calibration and methods of performing the same

Methods and apparatuses for compensating for frequency mismatch between a base station and mobile station are disclosed. At a first oscillator, a fixed reference oscillation signal is generated. At a second oscillator, a baseband oscillation signal is generated. A frequency divided version of the baseband oscillation signal is locked to a frequency divided version of the first reference oscillation signal. At a third oscillator, a first RF oscillation signal is generated. A frequency divided version of the first RF oscillation signal is locked to the frequency divided version of the second reference oscillation signal. A frequency adjustment signal is inputted to the second and third oscillators. At the second and third oscillators, frequency errors of the baseband oscillation signal and first RF oscillation signal, respectively, are compensated based on the frequency adjustment signal.

Method and apparatus for compensating for frequency errors between base station and mobile station

A system and method are provided for direct-conversion of a modulated radio-frequency (RF) signal. After receiving an RF signal, the RF signal is mixed with a plurality of oscillator signals with different phases in an interleaving manner.

Direct-conversion receiver system and method with quadrature balancing and DC offset removal

A multi-mode wireless device having a transceiver including a multi-mode transmitter and a multi-mode receiver. The transmitter can include a multi-mode transmit baseband portion configured to support all of the transmit modes. Similarly, the receiver can include a multi-mode baseband portion that is configured to support all of the receive modes. The transmitter can also include a frequency conversion stage that can convert the output from the transmit baseband portion to the desired transmit frequency. Multiple power amplifiers in parallel, each configured to support one or more of the operating modes, can selectively amplify the transmit signals. The receiver can include multiple low noise amplifiers (LNAs) in parallel, each configured to selectively amplify the received signals of one or more of the operating modes. The output of the LNAs can be coupled to a frequency conversion stage that downconverts the received signals and provides them to the baseband portion.

Transmitter and receiver architecture for multi-mode wireless device

A system and method are provided for communicating utilizing a plurality of different communication standards. To accomplish this, included is a single transceiver that utilizes a plurality of different communication standards.

Multi-mode wireless bridge system and method using a single-radio transceiver

A system and method are provided for communicating a radio frequency (RF) signal. In use, a baseband signal is mixed with a plurality of oscillator signals with different phases in an interleaving manner. The mixed baseband signal is then communicated as an RF signal.

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San Diego, CA, United States of America

Lon Christensen