Abstract: A reconfigurable baseband filter for use in a multimode communication system is disclosed. One or more filter elements can each be configured as a plurality of sub-elements. The value of each of the filter elements can be varied by switching between at least two of the plurality of sub-elements. Switching noise within a desired passband can be reduced by switching at a rate that is greater than the desired passband. The switching noise in the passband can be further reduced by pseudo-randomly switching between the sub-elements. The filter can use a delta-sigma modulator to generate a pseudo-random switching signal.

Abstract: 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.

Abstract: An FSK receiver comprising: 1) demodulation circuitry for receiving an incoming FSK signal and generating a baseband signal comprising an amplitude modulated symbol stream, of Logic 0 symbols and Logic 1 symbols having a data rate, R; 2) auto-correlation circuitry for sampling the baseband signal S times during each symbol and generating an auto-correlation function comprising a sample stream of N-bit samples having a data rate, S×R, and having positive-going peaks approximately coinciding with the center of the Logic 1 symbol in a 010 sequence in the baseband signal and negative-going peaks approximately coinciding with the center of the Logic 0 symbols in a 101 sequence in the baseband signal; and 3) decision circuitry for receiving the auto-correlation function and deciding a logic level of a first symbol as a function of: 1) a comparison of a signal level of a center sample of the first symbol and a mean signal level of the auto-correlation function and 2) a comparison of the signal level of the center sa

Abstract: 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.

Abstract: A radio frequency (RF) transceiver having improved low power operating modes. The RF transceiver comprises: 1) a radio frequency (RF) modem section comprising: a) receive path circuitry for receiving and down-converting an incoming RF signal to thereby produce an incoming baseband signal; and b) transmit path circuitry for receiving and up-converting an outgoing baseband signal to thereby produce an outgoing RF signal; 2) a baseband section comprising baseband circuitry for receiving and processing the incoming baseband signal and for generating the outgoing baseband signal; and 3) a power-saving apparatus for determining that the baseband section is idle and, in response to the determination, reducing a power supply voltage providing power to the baseband section.

Abstract: A method includes identifying a setting for a capacitor bank associated with a voltage-controlled oscillator in a closed-loop phase-locked-loop. The setting represents a combination of one or more capacitors in the capacitor bank. The method also includes estimating a gain introduced by the closed-loop phase-locked-loop when the oscillator operates using the identified setting. The method further includes estimating a response of a loop filter in the phase-locked-loop and identifying one or more coefficients for a digital filter using the identified gain and the identified loop filter response. The digital filter is operable to filter an input signal. In addition, the method includes modulating the filtered input signal using the phase-locked-loop to produce an output signal.

Abstract: A signal detection circuit for receiving a digital baseband signal comprising an amplitude modulated symbol stream of Logic 0 symbols and Logic 1 symbols, each of the Logic 0 and Logic 1 symbols comprising S sequential samples, wherein the amplitude modulated symbol stream contains a preamble of N known symbols preceding a plurality of user data symbols. The signal detection circuit comprises: A) a signal mean determination circuit that receives G samples from the digital baseband signal and determines an amplitude mean value associated with the amplitude modulated symbol stream; and B) a correlation circuit that detects the preamble.

Abstract: 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.

Abstract: 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.

Abstract: A frequency shift keyed (FSK) receiver for demodulating an incoming transmitted signal comprising: 1) a phase-locked loop for receiving an oscillator reference signal having a frequency F1 and generating a reference carrier frequency signal having a desired frequency N1(F1), wherein N1 may be a non-integer value, the phase-locked loop comprising: a) a phase detector having a first input for receiving the oscillator reference signal and a second input; and b) a frequency divider circuit for dividing an actual frequency of the reference carrier frequency signal by an adjustable integer value N2 applied to a control input of the frequency divider circuit to generate a feedback signal applied to the second input of the phase detector.

Abstract: An FSK receiver comprising: 1) demodulation circuitry for receiving an incoming FSK signal and generating a baseband signal comprising an amplitude modulated symbol stream of Logic 0 symbols and Logic 1 symbols having a data rate, R; 2) auto-correlation circuitry for sampling the baseband signal S times during each symbol and generating an auto-correlation function comprising a sample stream of N-bit samples having a data rate, S×R, and having positive-going peaks approximately coinciding with the center of the Logic 1 symbol in a 010 sequence in the baseband signal and negative-going peaks approximately coinciding with the center of the Logic 0 symbols in a 101 sequence in the baseband signal; and 3) decision circuitry for receiving the auto-correlation function and deciding a logic level of a first symbol as a function of: 1) a comparison of a signal level of a center sample of the first symbol and a mean signal level of the auto-correlation function and 2) a comparison of the signal level of the center sam

Abstract: A method includes identifying a setting for a capacitor bank associated with a voltage-controlled oscillator in a closed-loop phase-locked-loop. The setting represents a combination of one or more capacitors in the capacitor bank. The method also includes estimating a gain introduced by the closed-loop phase-locked-loop when the oscillator operates using the identified setting. The method further includes estimating a response of a loop filter in the phase-locked-loop and identifying one or more coefficients for a digital filter using the identified gain and the identified loop filter response. The digital filter is operable to filter an input signal. In addition, the method includes modulating the filtered input signal using the phase-locked-loop to produce an output signal.

Abstract: A reconfigurable baseband filter for use in a multimode communication system is disclosed. One or more filter elements can each be configured as a plurality of sub-elements. The value of each of the filter elements can be varied by switching between at least two of the plurality of sub-elements. Switching noise within a desired passband can be reduced by switching at a rate that is greater than the desired passband. The switching noise in the passband can be further reduced by pseudo-randomly switching between the sub-elements. The filter can use a delta-sigma modulator to generate a pseudo-random switching signal.

Abstract: 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.

Abstract: 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.