Abstract: A communications device and receiver system and method to efficiently distribute functions among radio frequency (RF), analog front end (AFE) and baseband modules for ultra-low power consumption comprising a wideband receiver subsystem selectively coupled to a signal input receiving a first frequency band, a narrowband received subsystem selectively coupled to the signal input receiving a second frequency band and, a controller configured to monitor the first frequency band using the first receiver subsystem and if a wake up signal is detected using the first receiver subsystem, connect the second receiver subsystem to the signal input and tune the second receiver subsystem to a channel transmitting the wake up signal, the wake up signal including channel selection information defining the channel for subsequent communications. Wherein, the two frequency bands overlap and center on different frequencies.

Abstract: An efficient method and transceiver architecture combines elements to enable and facilitate the low power operation of a communications device; the combination of design elements, features, and functionalities are efficiently distributed among RF, APE, and baseband modules in order to exploit opportunities that can serve the goal of low or ultra low power consumption.

Abstract: A variation on conventional DPSK binary modulation schemes is provided. One modulation scheme uses 3?/8 differential binary phase shift keying (3?/8-DBPSK) where one symbol is transmitted by phase change of 3?/8 radians and the other symbol is transmitted by phase change of ?5?/8 radians. Alternatively, this can be thought of as adding a constant 3?/8 radians to the symbol angle for every bit modulated by conventional DBPSK. In another example, assume a first and second symbols, k?1 and k, respectively, are sent. Where k is the same symbol as k?1, a phase rotation of 3?/8 radians from the kth symbol is used to represent the symbol at k?1; and where the k?1 symbol is the opposite of the kth symbol, its rotation 11?/8 radians from the kth symbol. Other modulation schemes using other phase rotations can be provided.

Abstract: A tap-selectable Viterbi equalizer comprises means for determining at least one symbol from a previous determination assigned to a first state, means for determining a second state of the plurality of states and determining a surviving path metric by comparing path metrics originating from the determined symbol, means for determining the value of a previous symbol with respect to the symbol of the surviving state, and calculating means for generating a reduced trellis by calculating only path metrics for states in which the previous symbol has the determined value.

Abstract: A calibration apparatus for a quadrature modulation system with a quadrature modulation compensator and a logarithmic envelop detector, wherein a parameter update of the quadrature modulation compensator is derived by utilizing a transformed offset value and a transformed gain value of the logarithmic envelop detector as intermediate parameters, and the transformed offset and the transformed gain parameters are used in a training sequence of the quadrature modulation compensator.

Abstract: A digital arrangement for selecting a channel coefficient and DC estimate comprises a demultiplexer receiving a digital input signal splitting the digital input signal into a first and second signal, a first joint detection unit receiving the first signal generating a first channel coefficient and DC estimate, a second joint detection unit receiving the second signal generating a second channel coefficient and DC estimate, a first and second error determination unit receiving the first and second channel coefficients and DC estimates, respectively for generating a first and second error signal, a decision unit receiving the first and second error signals generating a control signal, and a selection unit controlled by the control signal for selecting the first or second channel coefficient and DC estimate.

Abstract: A calibration apparatus for a quadrature modulation system with a quadrature modulation compensator and a logarithmic envelop detector, wherein a parameter update of the quadrature modulation compensator is derived by utilizing a transformed offset value and a transformed gain value of the logarithmic envelop detector as intermediate parameters, and the transformed offset and the transformed gain parameters are used in a training sequence of the quadrature modulation compensator.

Abstract: A DC tracking arrangement includes a first tracking unit for slow tracking receiving an input signal and generating a first output signal, a second tracking unit for fast tracking receiving the input signal and generating a second output signal, and a decision unit receiving the first and second output signal for selecting the first or second output signal.

Abstract: A method of processing a sequence of digital symbols comprises the steps of processing the sequence of digital symbols and determining an uncertainty in the processing. If the uncertainty exceeds a predetermined threshold, then the method further comprises the steps of processing at least two sequences of digital symbols wherein at least one parameter is set differently in each sequence, and deciding upon a calculated error for each sequence which sequence is used to generate an output signal.

Abstract: A digital signal detector arrangement comprises at least two selectable baseband filters for receiving a digital signal, a signal estimator receiving the output signal of the selected baseband filter, a modulator unit receiving the estimated signal from the signal estimator, a subtractor for subtracting the modulated signal from the received digital signal, and a determination unit receiving the signal from the subtractor for selecting the baseband filter.

Abstract: A method of determining a trellis from a sequence of n symbols in a Viterbi detector. The method includes the steps of receiving a sequence of n symbols, defining partitioned sets according to a decision tree structure, and determining size of each set partitioning according to tap energy of the channel. The method also includes steps of determining a reduced set of connection paths between the current layer and a destination layer in the trellis by determining a value of a most likely oldest partitioned set in a current layer; and calculating branch metrics only for the current layers in the trellis in which the oldest partitioned set matches the determined value.

Abstract: A DC tracking arrangement comprises a first tracking unit for slow tracking receiving an input signal and generating a first output signal, a second tracking unit for fast tracking receiving the input signal and generating a second output signal, and a decision unit receiving the first and second output signal for selecting the first or second output signal.

Abstract: A digital signal detector arrangement comprises at least two selectable baseband filters for receiving a digital signal, a signal estimator receiving the output signal of the selected baseband filter, a modulator unit receiving the estimated signal from the signal estimator, a subtractor for subtracting the modulated signal from the received digital signal, and a determination unit receiving the signal from the subtractor for selecting the baseband filter.

Abstract: A digital arrangement for selecting a channel coefficient and DC estimate comprises a demultiplexer receiving a digital input signal splitting the digital input signal into a first and second signal, a first joint detection unit receiving the first signal generating a first channel coefficient and DC estimate, a second joint detection unit receiving the second signal generating a second channel coefficient and DC estimate, a first and second error determination unit receiving the first and second channel coefficients and DC estimates, respectively for generating a first and second error signal, a decision unit receiving the first and second error signal generating a control signal, and a selection unit controlled by the control signal for selecting the first or second channel coefficient and DC estimate.

Abstract: A method of processing a sequence of digital symbols comprises the steps of processing the sequence of digital symbols and determining an uncertainty in the processing. If the uncertainty exceeds a predetermined threshold, then the method further comprises the steps of processing at least two sequences of digital symbols wherein at least one parameter is set differently in each sequence, and deciding upon a calculated error for each sequence which sequence is used to generate an output signal.

Abstract: A method of determining a trellis from a sequence of n symbols in a Viterbi detector. The method includes the steps of receiving a sequence of n symbols, defining partitioned sets according to a decision tree structure, and determining size of each set partitioning according to tap energy of the channel. The method also includes steps of determining a reduced set of connection paths between the current layer and a destination layer in the trellis by determining a value of a most likely oldest partitioned set in a current layer; and calculating branch metrics only for the current layers in the trellis in which the oldest partitioned set matches the determined value.

Abstract: A tap-selectable Viterbi equalizer comprises means for determining at least one symbol from a previous determination assigned to a first state, means for determining a second state of the plurality of states and determining a surviving path metric by comparing path metrics originating from the determined symbol, means for determining the value of a previous symbol with respect to the symbol of the surviving state, and calculating means for generating a reduced trellis by calculating only path metrics for states in which the previous symbol has the determined value.