Abstract: Multi-drop communications channels can have significantly deep notches in their frequency response causing a corresponding limitation of the effective data transmission rate. A special time-ordered coding method is described which results in the emitted spectrum of the data stream transmitted into the channel having a notch at the same frequency as the notch in the channel frequency response, permitting channel receivers to successfully decode the transmitted data stream. The described coding method may be applied at various multiples of the channel notch frequency to support different throughput rates, and may be combined with other coding techniques such as group or vector signaling codes.

Abstract: Beam measurement values are computed by transforming a signal to a beamspace representation using a beamforming matrix that includes a plurality of columns that define a plurality of beams. A second plurality of beams is selected from the plurality of beams based on a power captured by each beam derived from the computed beam measurement values. For each beam of the second plurality of beams as a first beam, a spatial phase shift component and a temporal delay component is computed based on the fixed spatial angle associated with the first beam and a carrier frequency, a filter is defined using the spatial phase shift component and the temporal delay component, a beam measurement value associated with the first beam from the computed beam measurement values is selected, and the defined filter is applied to the selected beam measurement value to define a filtered value.

Abstract: Phase locked loop circuitry operates digitally, to at least a large extent, to select from a plurality of phase-distributed candidate clock signals the signal that is closest in phase to transitions in another signal such as a clock data recovery (“CDR”) signal. The circuitry is constructed and operated to avoid glitches in the output clock signal that might otherwise result from changes in selection of the candidate clock signal. Frequency division of the candidate clock signals may be used to help the circuitry support serial communication at bit rates below frequencies that an analog portion of the phase locked loop circuitry can economically provide. Over-transmission or over-sampling may be used on the transmit side for similar reasons.

Abstract: In an example, an apparatus for clock data recovery (CDR) includes a data slicer operable to generate data samples derived from a transmitted signal, and an error slicer operable to generate error samples derived from a transmitted signal. The apparatus further includes a CDR circuit operable to generate sampling clock phase for the data slicer and the error slicer from output of the data samples and the error samples. The apparatus further includes a decision adapt circuit operable to set a decision threshold of the error slicer, wherein for each main-cursor data sample of the data samples the decision adapt circuit is operable to adjust the decision threshold based on a function of at least one pre-cursor data sample, at least one post-cursor data sample, or a combination of at least one pre-cursor data sample and at least one post-cursor data sample.

Abstract: A communication apparatus includes: a switching device which modulates at least one of a first signal with a first frequency and passed through a first communication device and a second signal not passed through the first communication device at a second frequency lower than the first frequency; a signal combiner which combines together the first and second signals, at least one of which is modulated, to generate a composite signal containing a switching frequency component with an amplitude in response to the phase difference between the first and second signals at the second frequency; and a control unit which, based on the switching frequency component, obtains as a reference phase adjustment amount a phase adjustment amount applied by a phase adjuster in the first communication device.

Abstract: A partial response decision feedback equalizer (PrDFE) includes a receiver including at least first and second comparators operative to compare an input signal representing a sequence of symbols against respective thresholds and to respectively generate first and second receiver outputs. A first selection stage is provided to select (a) between the first comparator output and a first resolved symbol according to a first timing signal, and (b) between the second comparator output and the first resolved symbol according to the first timing signal, to produce respective first and second selection outputs. A second selection stage selects between the first and second selection outputs according to a selection signal. The selection signal is dependent on a prior resolved symbol that precedes the first resolved symbol in the sequence.

Abstract: A wireless communication terminal apparatus wherein CoMP communication can normally be performed without increasing the overhead of an upstream line control channel. In this apparatus, a spreading unit (214) primarily spreads a response signal by use of a ZAC sequence established by a control unit (209). A spreading unit (217) secondarily spreads the response signal, to which CP has been added, by use of a block-wise spread code sequence established by the control unit (209). The control unit (209) controls, in accordance with sequence numbers and a hopping pattern established therein, the circular shift amount of the ZAC sequence to be used for the primary spread in the spreading unit (214) and the block-wise spread code sequence to be used for the secondary spread in the spreading unit (217). The hopping pattern established in the control unit (209) is a hopping pattern common to a plurality of base stations that CoMP-receive the response signal.

Abstract: A phase control method in the present disclosure includes dividing, by a power divider, the high frequency current into at least two current branches, and separately feeding the at least two current branches into corresponding radio frequency input ports on a digital phase shifter, determining, by the switch controller according to the digital control flow, radio frequency paths that are in the digital phase shifter and for the at least two current branches fed into the digital phase shifter, and controlling the drive voltage to act on the digital phase shifter, and separately establishing, by the digital phase shifter according to the drive voltage and for the at least two current branches, radio frequency paths for currents to flow through, and controlling duration of phase delays for the at least two current branches by controlling lengths of the radio frequency paths through which the at least two current branches flow.

Abstract: A subassembly for an integrated wireless module is provided. The subassembly includes an integrated-wireless-module input/output (I/O) connector, a modem controller; at least one internal antenna, and at least two modem connectors communicatively coupled to the modem controller, the modem connectors configured to interface with at least two modems. The modem controller digitally selects to one of: communicatively couple one of the at least two modem connectors to one of the at least one internal antenna; communicatively couple one of the at least two modem connectors to the integrated-wireless-module I/O connector; and communicatively couple a first one of the at least two modem connectors to one of the at least one internal antenna and communicatively couple a second one of the at least two modem connectors to the integrated-wireless-module I/O connector.

Abstract: The invention relates to frequency conversion systems, in particular for use as up-converters or down-converters in radiofrequency (RF) receivers or transmitters, exemplary embodiments including a radiofrequency receiver including an RF signal input; a mixing module including a first plurality of IF amplifiers each connected to the RF signal input via a switch; a multi-phase local oscillator signal generator configured to provide a switching signal to each switch; and a summing module configured to receive output signals from each of the IF amplifiers and to provide a second plurality of output IF signals from a weighted sum of the IF amplifier output signals, wherein the second plurality is different to the first plurality.

Abstract: A method for compensating for transmission channel distortion effects for a data signal transmitted from a first computing device via the transmission channel to a second computing device is provided.

Abstract: A method for generating a filter bank for receiving a signal modulated by continuous phase modulation, the modulated signal being able to be broken down as a sum of a plurality of amplitude-modulated signals, each amplitude-modulated signal being expressed by a product between a complex pseudo-symbol and a temporal component with a waveform predefined according to the parameters of the modulation, includes: evaluating, over a duration (T) that is equal to the duration of a symbol, all waveforms of the signal from the parameters of the continuous phase modulation and the breakdown in the form of a sum of a plurality of amplitude-modulated signals, retaining all evaluated waveforms that are different from one another, constructing a filter bank made up of a plurality of filters whose temporal responses are equal to the retained waveforms, which are limited to a duration equal to the duration of a symbol.

Abstract: Aspects disclosed in the detailed description include skew control for three-phase communication. A three-phase communication involves three signal branches. A signal skew may occur when one signal branch is being coupled to a common mode voltage while another signal branch is being decoupled from the common mode voltage. In this regard, in one aspect, an impedance mismatch is introduced in the signal branch being coupled to the common mode voltage to help shift a rightmost crossing of the signal skew leftward. In another aspect, a current source or a current sink is coupled to the signal branch being decoupled from the common mode voltage to help shift a leftmost crossing of the signal skew rightward. By shifting the rightmost crossing leftward and the leftmost crossing rightward, it is possible to reduce the signal skew, thus leading to reduced jitter and improved data integrity in the three-phase communication.

Abstract: A communication system uses a bus to transmit information, by receiving signals and mapping them to a second set of signals representing codewords of a superposition signaling code, and transmitting the second set of signals. The superposition signaling code can comprise more than one layer. The pin-efficiency can be larger than 1. The system may encode bits into a codeword of a superposition signaling code that is defined by two basis vectors of predetermined size and then have two encoders for permutation modulation codes defined by the basis vectors. The bits of information are divided into a first part representing a predetermined number of bits and a second part representing a predetermined number of bits, with the parts provided to the respective encoding circuits and their outputs combined by a superposition.

Abstract: A method of transmitting a data stream over a communication channel, the method comprising: providing symbol sets having different numbers of symbols; modulating data in the data stream that warrant different degrees of protection against noise onto symbols from symbol sets having different numbers of symbols, wherein which symbol set given data in the stream is modulated onto is independent of symbol sets onto which other data in the data stream is modulated onto; and transmitting the symbols.

Abstract: A transadmittance amplifier stage is coupled to a transimpedance amplifier stage to form a continuous time linear equalizer. The transadmittance amplifier stage has first and second gain paths and is configured to input a first signal and output a second signal. The first gain path is configured to provide a DC gain recovery and a first high frequency gain to the first signal. The second gain path is configured to provide a second high frequency gain to the first signal. The second signal is generated by the transadmittance amplifier stage based on the gain recovery of the first signal and the high frequency gains of the first signal. The transimpedance amplifier stage is configured to input the second signal from the transadmittance amplifier stage and convert the second signal to an output voltage signal.

Abstract: A clock and data recovery device includes a phase detector, a quantizer, and a loop filter. The phase detector produces a phase error samples at an output representing a phase difference between a phase-adjusted clock and an input data signal. The quantizer, coupled to the output of the phase detector and responsive to high threshold and low threshold values, produces a tri-valued quantized phase error samples at an output. The loop filter filters either the quantized phase error samples or the phase error samples to control the phase-controlled clock. A frequency detector, determining the frequency of jitter present in the input data signal, addresses a look-up table to provide the jitter-frequency dependent high and low threshold values and to control which phase error samples is processed by the loop filter. The frequency detector determines the jitter frequency by taking the ratio of peak values of low pass-filtered phase error samples.

Abstract: Techniques for providing codebooks extended by gain information that can be transmitted in a reduced amount of signaling are disclosed. A user equipment includes a transmission and reception unit communicating a radio signal with a base station in accordance with MIMO (Multiple Input Multiple Output) transmission and a codebook storage unit stores predefined codebooks to specify precoding matrices for use in the MIMO transmission. The codebooks are arranged to represent phase information and gain information and a channel measurement unit measures channel conditions based on reference signals transmitted from multiple antennas in the base station. A codebook selection unit selects a codebook to be indicated to the base station from the stored codebooks based on the measured channel conditions and instructs the transmission and reception unit to indicate feedback information to the base station and the feedback information includes a codebook index for identifying the selected codebook.

Abstract: A method for demodulating a signal in a receiver including at least two antennas, each receiving a signal, the received signals corresponding to a single emitted signal including symbol frames in which certain symbols, referred to as driver symbols, are known to the receiver, the method including: noise whitening in order to form two combined signals, the noise components of which are separate; normalizing the noise components of the combined signals in order to form two signals, the noise components of which are separate and have equal average standards; and performing signal demodulation with the maximum combination of the signal-to-noise ratio on the two signals, the noise components of which are separate and which have equal average standards, wherein during the first noise-whitening step for forming the two combined signals, the latter are determined retroactively using the maximum criterion.

Abstract: Methods and a receiver of positioning a spurious signal for reducing the impact of the spurious signal on a received Orthogonal Frequency Division Multiplexing, OFDM signal, are presented. The method comprises determining the frequency of a spurious signal (steps 102, 204, 404), determining the frequency for the respective sub-carrier of the OFDM signal and the difference between the frequency of a sub-carrier and the frequency of a spurious signal (steps 104, 206, 406), and adjusting at least one of: the frequency of the first oscillator (step 208) and a parameter related to the frequency of a second oscillator, to decrease the frequency difference between a sub-carrier and a spurious signal (steps 106, 212, 408). By positioning a spurious signal at or near a sub-carrier frequency, the performance impact of the spurious signal is reduced, and the receiver performance improved.