Spreadtrum Communications USA Inc.

Motorola Corporation

Spreadtrum Communications Corporation

Spreadtrum Communication USA Inc.

David Ryan Haub

Louis Jay Vannatta

Zhigang Xu

Jarrett Malone

Hugh Kennedy Smith

Lon Christensen

Zebin Wang

Christopher N Kurby

James P Phillips

Richard E Mach

Michael D Kotzin

Mahibur Rahman

James David Hughes

Arthur Christopher Leyh

Charles LeRoy Sobchak

John Thomas Solar

Daniel Neil Ralston

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

First and second inputs are received. The first input indicates a frequency offset of a frequency band allocated for signal transmission. The said allocated band is a subband of a total band available for transmission. The second input indicates a bandwidth of the allocated band. One or more filters of a transmitter of a communications system are controlled to operate cumulatively in a lowpass filtering mode, wherein the highest frequency in a pass band in the lowpass filtering mode is less than the highest frequency of the total band available for transmission. A signal is filtered using the filter(s).

Method and apparatus for transmitter optimization based on allocated transmission band

A receiver architecture optimizes receiver performance in the presence of interference. In various embodiments, power estimation circuits are used with variable selectivity to determine the exact nature of the interference and to optimize the performance correspondingly. The variable selectivity is achieved using stages of filtering with progressively narrower bandwidths. Also, the actual method of optimizing the receiver performance is an improvement compared to the traditional techniques in that the gain settings and the baseband filter order (stages to be used) will be optimized based on the nature of the interference as determined by the power detector measurements. For a device such as a cellular phone that operates in a dynamic and changing environment where interference is variable, embodiments advantageously provide the capability to modify the receiver's operational state depending on the interference.

Detection and mitigation of interference in a receiver

Embodiments include a novel receiver architecture to optimize receiver performance in the presence of interference. In various embodiments, the presence of interference is detected, and the relative frequency location of the interference is detected. The relative frequency location specifies whether the frequency of the interference is high side (above the desired signal, i.e., at a higher frequency) or low side (below the desired signal). The receiver is configured based on the detected interference and relative location thereof. For a device such as a cellular phone that operates in a dynamic and changing environment where interference is variable, embodiments advantageously provide the capability to modify the receiver's operational state depending on the interference.

Detection and mitigation of interference based on interference location

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

Embodiments include a novel receiver architecture to optimize receiver performance in the presence of interference. In various embodiments, power estimation circuits are used to determine the exact nature of the interference and to optimize the performance correspondingly. Variable selectivity of at least one power estimation circuit is achieved using a filter with variable bandwidth, with power measurements taken using different bandwidth settings. Also, the actual method of optimizing the receiver performance is novel compared to the prior art in that the gain settings and the baseband filter order (stages to be used) will be optimized based on the nature of the interference as determined by the power detector measurements. For a device such as a cellular phone that operates in a dynamic and changing environment where interference is variable, embodiments advantageously provide the capability to modify the receiver's operational state depending on the interference.

Detection and mitigation of interference in a multimode receiver using variable bandwidth filter

A novel receiver architecture optimizes receiver performance in the presence of interference. In various embodiments, power estimation circuits are used with variable selectivity to determine the exact nature of the interference and to optimize the performance correspondingly. The variable selectivity is achieved using stages of filtering with progressively narrower bandwidths. Also, the actual method of optimizing the receiver performance is novel compared to the prior art in that the gain settings and the baseband filter order (stages to be used) will be optimized based on the nature of the interference as determined by the power detector measurements. For a device such as a cellular phone that operates in a dynamic and changing environment where interference is variable, embodiments advantageously provide the capability to modify the receiver's operational state depending on the interference.

In a signal processing method, an input signal is provided at an input to a receiver. A bandwidth of the receiver is controlled to a predetermined wideband setting. For band in a plurality of frequency bands, the input signal is processed at the receiver with a mixer, an amplifier, and a filter, to generate a first processed signal, and a power spectral density of the processed signal is generated over that frequency band, to provide a frequency domain signal for that frequency band. Based on the frequency domain signals corresponding to each frequency band in the plurality of frequency bands, a frequency domain representation of the processed signal is reconstructed over a reconstruction band having a bandwidth larger than the predetermined wideband setting. Based on the reconstructed frequency domain representation, a spectral component is identified corresponding to at least one cellular telephony access mode.

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Lake in the Hills, IL, United States of America

David Ryan Haub