Abstract: An apparatus for and method of extending the dynamic range of a RF communications receiver. The invention provides a mechanism for controlling the gain of both the LNA and down conversion mixer in the front end portion of an RF receiver. Both the LNA and the mixer are adapted to have both low and high gain modes of operation. The control mechanism typically comprises a two bit gain control that places both the LNA and mixer in one of four operating gain mode states. The selection of the most appropriate operating gain mode state, is preferably determined in accordance with various metrics such as the received levels of the desired signal, levels of interference signals, bit error rate and receiver RSSI.

Abstract: A novel apparatus for and a method of estimating, calibrating and tracking in real-time the gain of a radio frequency (RF) digitally controlled oscillator (DCO) in an all-digital phase locked loop (ADPLL). Precise setting of the inverse DCO gain in the ADPLL modulating path allows direct wideband frequency modulation that is independent of the ADPLL loop bandwidth. The gain calibration technique is based on a steepest descent iterative algorithm wherein the phase ADPLL error is sampled and correlated with the modulating data to generate a gradient. The gradient is then scaled and added to the current value of the DCO gain multiplier.

Abstract: An apparatus for and method of extending the dynamic range of a RF communications receiver. The invention provides a mechanism for controlling the gain of both the LNA and down conversion mixer in the front end portion of an RF receiver. Both the LNA and the mixer are adapted to have both low and high gain modes of operation. The control mechanism typically comprises a two bit gain control that places both the LNA and mixer in one of four operating gain mode states. The selection of the most appropriate operating gain mode state, is preferably determined in accordance with various metrics such as the received levels of the desired signal, levels of interference signals, bit error rate and receiver RSSI.

Abstract: A digital nonlinear adaptive mechanism for frequency offset compensation for use in a digital Frequency Shift Keying (FSK) receiver such as a Bluetooth GFSK receiver. The mechanism is intended to aid in the recovery of a frequency-modulated signal in the presence of an unknown additive frequency offset, which could be greater than the peak frequency deviation and which must be suppressed to enable proper data recovery in the receiver. The mechanism utilizes a demodulator to convert the frequency offset into a digitally represented DC level. This level is extracted by a non-linear estimator based on peak detectors and filters. Active suppression of the DC level is achieved by feed-forwarding the estimated value into a subtractor that removes it from the digital signal. A gear shift mechanism incorporated within the DC estimation block enables the dynamic control of the DC estimation process.

Abstract: A nonlinear adaptive mechanism for amplitude adjustment and DC estimation and compensation for use in a digital receiver such as a Bluetooth GFSK receiver. The mechanism uses a feed-forward technique that can be used in a multi-stage scheme to perform both DC compensation and amplitude adjustment of an input signal for use by subsequent processing stages. In a first stage, coarse DC offset compensation is performed and the offset estimates generated are subsequently frozen. In a second stage, the incoming signal with the DC offset subtracted from it, is then scaled into a narrow predefined range of amplitudes using a scaling mechanism that works with gains and attenuations that are powers of two in order to simplify implementation. In a third stage, the scaled compensated signal is then injected again into the same DC estimation mechanism, which was previously used for DC compensation in the first stage, for further DC offset estimation and compensation (i.e. fine DC estimation and compensation).

Abstract: A nonlinear adaptive mechanism for amplitude adjustment and DC estimation and compensation for use in a digital receiver such as a Bluetooth GFSK receiver. The mechanism uses a feed-forward technique that can be used in a multi-stage scheme to perform both DC compensation and amplitude adjustment of an input signal for use by subsequent processing stages. In a first stage, coarse DC offset compensation is performed and the offset estimates generated are subsequently frozen. In a second stage, the incoming signal with the DC offset subtracted from it, is then scaled into a narrow predefined range of amplitudes using a scaling mechanism that works with gains and attenuations that are powers of two in order to simplify implementation. In a third stage, the scaled compensated signal is then injected again into the same DC estimation mechanism, which was previously used for DC compensation in the first stage, for further DC offset estimation and compensation (i.e. fine DC estimation and compensation).

Abstract: A digital demodulator employing a digital differential detection mechanism based on extracting phase differences directly from the I and Q signals after downconversion to zero-IF and image rejection are performed. The phase of the input I and Q signals is determined using the principle that the phase is equivalent to arctan 1 ( Q I ) .

Abstract: An on-chip test mechanism for transceiver power amplifier and oscillator frequency for use with the transmitter portion of an integrated RF transceiver. The invention eliminates the need for expensive RF test equipment, permitting the use of low cost test equipment to test an integrated RF transmitter. In addition, test time spent to verify the power levels and frequency ranges of a tested transmitter is reduced, further reducing testing costs. The RF output from the power amplifier in the transmitter is input to a built-in dedicated analog comparator having a configurable threshold. The threshold is adjusted to a predetermined level at which crossings start to occur at the comparator output. The comparator outputs pulses only if the power amplifier output is above a minimum configurable level.

Abstract: An on-chip receiver sensitivity test mechanism for use in an integrated RF transmitter wherein the transmitter and the receiver share the same oscillator. The mechanism obviates the need to use expensive RF signal generator test equipment with built-in modulation capability and instead permits the use of very low cost external RF test equipment. The invention utilizes circuitry already existing in the transceiver, namely the modulation circuitry and local oscillator, to perform sensitivity testing. The on-chip LO is used to generate the modulated test signal that otherwise would need to be provided by expensive external RF test equipment with modulation capability. The modulated LO signal is mixed with an externally generated unmodulated CW RF signal to generate a modulated signal at IF which is subsequently processed by the remainder of the receiver chain. The recovered data bits are compared using an on-chip BER meter or counter and a BER reading is generated.

Abstract: An on-chip reduced complexity modulation noise estimation mechanism for performing nonlinear signal processing to analyze modulation noise to determine whether a semiconductor device under test complies with the performance criteria set by specifications or a standard corresponding thereto. When used in a two-point transmitter modulation architecture, the mechanism relies on the fact that the noise statistics at the output of the transmitter can be determined by observing the phase error output of the phase detector within the phase locked loop. In the digital embodiment of the mechanism, the phase error signal is compared to a configurable threshold value to generate an exception event. If the number of exception events exceeds a configurable max_fail value after comparisons of a configurable number of phase error samples, the test fails. A pass/fail signal is output reflecting the result of the test.

Abstract: An adaptive data slicer which functions to adapt to changes in the properties of a signal input thereto by producing a near optimal slicing threshold in accordance with the input signal for use in a decision circuit. The slicing level is considered optimal when its use in the decision circuit minimizes the bit error probability. The data slicer utilizes two peak detectors, a maximum peak detector for detecting the highest levels of the input signal and a minimum peak detector for detecting the lowest levels of the input signal.

Abstract: A novel frequency synthesizer incorporating a band switching VCO having a low KVCO tuning factor enabling operation with low supply voltage and low susceptibility to noise and frequency pulling. The VCO has a low tuning factor that covers only a small portion of the operating frequency range, depending on the number of bands into which the frequency range is divided. The normal phase locked loop operation of the synthesizer is preceded by an open loop band selection procedure which results in faster lock time and a lower required tuning voltage range for the VCO. The frequency band selection is made using frequency measurements. Alternatively, a band select LUT and channel LUT are generated a priori during a calibration stage in order to speed frequency acquisition and band selection.

Abstract: A wireless device (100) having an optimum alert sequence definition analyzes its environment, including time and type of incoming call, and selects an appropriate alert signal sequence. A central processing unit (114) included within the device (100) is responsive to a transmitted signal from an external communications device to generate active and passive sonic sensing. The reflected signal received through the microphone (110) and a predetermined set of values or ranges stored in a memory (102) coupled to the central processing unit (114) are used as input for a program of instructions tangibly embodied in a programmable storage device executable by the central processing unit (114). Based upon processing of this reflected signal, the central processing unit (114) determines which alert signal is optimum given the environment.

Abstract: A system and method for wireless communication between two devices allows the transfer of location information through a cellular or “BLUETOOTH” link that can be used to provide a continuous indication of estimated distance and direction relative to the two devices in communication with one another.

Abstract: An apparatus for and a method of providing a visual and/or audible indication of a numerical quantity. The quantity may be derived from any source such as an analog or digital quantity. The invention has utility in any application wherein it is desirable to visually and/or audibly display the magnitude of a quantity. An example system is described which provides a visual and/or audible indication of the received signal strength (RSSI) in an RF receiver. A visual indicator such as an LED is flashed a number of times corresponding to the magnitude of an input signal. Alternatively, or in combination, an audible indicator such as a buzzer can be beeped a number of times corresponding to the magnitude of the input signal. A digitized quantity to be indicated can be calculated by or input to a microcontroller or other processor that is suitably programmed to convert the magnitude of the digitized quantity to a number representing the number of flashes or beeps.

Abstract: The present invention is an apparatus and method thereof for performing frequency hopping communication with another party over a subset of hopping frequencies from available frequencies. The spectrum is arranged into a plurality of segments, with each segment corresponding to a subset of the spectrum of frequencies, preferably a contiguous subset of the spectrum. The apparatus includes a communication device for communicating with another party. The communication device receives data over a used segment from a plurality of the segments and signal strength data indicating a current reception power level for the hopping frequency from the other party. A processing unit analyzes the received data to determine an occurrence or non-occurrence of an error over the used segment and notifies the other party to modify the current transmission power level for that used segment according to the occurrence or non-occurrence of an error, via said communication means.