Abstract: A specialized preamble is provided to facilitate matrix channel estimation of a MIMO channel. In a particular implementation, a channel training preamble provided by the IEEE 802.11a standard is modified to facilitate MIMO channel estimation.

Abstract: This document discusses, among other things, digital-to-time converters (DTCs) and more particularly to parallel implementations of DTCs. In an example, an apparatus can include a first digital-to-time converter (DTC) configured to receive reference frequency information and first phase information of a polar transmitter and to provide a first portion of phase modulation information, a second DTC configured to receive second phase information of the polar transmitter and to provide a second portion of phase modulation information, and a combiner configured to receive the first portion and the second portion and to provide a phase modulated signal.

Abstract: A system including a transmitter and a receiver that are loosely synchronized, the transmitter encodes signal waveforms having a start time, a width and a height that are determined based on a range of possible relative drifts of a receiver clock with respect to a transmitter clock and the receiver decodes the waveforms based on a sequence of tests, chosen to account for any uncertainty that may arise due to the lack of tight synchronization.

Abstract: Disclosed are a device and method for automatically controlling frequency. The automatic frequency control device includes a frequency error detection unit configured to obtain a frequency error detection value of a received carrier, a frequency error prediction unit configured to calculate a first frequency error prediction value on the basis of the frequency error detection value when the frequency error detection value satisfies a preset first criterion, and a frequency error compensation unit configured to calculate a second frequency error prediction value by correcting the first frequency error prediction value, and compensate for a frequency of the carrier on the basis of the second frequency error prediction value when a frequency change rate of the received carrier satisfies a preset second criterion. Therefore, overshoot and undershoot effects are minimized, and thus frequency control may be correctly performed.

Abstract: Methods and apparatuses for information feedback and precoding have been provided. A method for processing communication data at a user equipment in a wireless communication system may comprise: deriving a spatial correlation matrix R of multiple transmit antennas of a base station based on an obtained downlink channel transmission matrix H; transforming a precoding codebook F according to the spatial correlation matrix R; selecting a precoding matrix Fs based on the transformed precoding codebook; and feeding back information about the spatial correlation matrix R and information about the selected precoding matrix Fs to the base station.

Abstract: A transmitter and/or receiver for performing frequency domain equalization is provided. A transmitter includes a pilot position determination unit for determining positions for inserting pilots in a frequency domain based on frequency spectrums of data, and a pilot insertion unit for inserting the pilots between the frequency spectrums of the data according to the determined positions for inserting the pilots.

Abstract: A method includes holding in a memory of a communication terminal multiple predefined vectors, each including signal autocorrelation values computed for a respective Doppler shift. A signal is received, and empirical autocorrelation values are calculated for the received signal. An actual Doppler shift of the received signal is estimated by selecting, from among the predefined vectors, a vector whose autocorrelation values best match the empirical autocorrelation values of the received signal.

Abstract: A method of frequency-domain filtering is provided that includes a plurality of filters, the plurality of filters including at least one constrained filter(s) W=I, I and at least one unconstrained filter(s) W=1,K? The method includes cascading the W k=i,K unconstrained filter(s). A single constraint window C is applied to the cascaded W=i,K unconstrained filter(s). The W=1,I constrained filter(s) are cascaded with the constrained cascaded Wk=1,K unconstrained filter(s) to form a resulting filter Wll=C(W 1{circle around (x)} . . . {circle around (x)} W){circle around (x)} W . . . W. The frequency domain representation of the single constraint window C may be based, at least in part, on a time domain representation of a single constraint window C that has been circularly shifted such that the frequency domain representation of the constraint window matches a property of the frequency domain representation of the cascaded W=1,K unconstrained filters.

Abstract: The present invention provides a virtual multiple-input multiple-output communication method and device. The method includes: determining a user set to which a user equipment in a sector belongs, where the user set includes a first user set and a second user set, a user equipment in the first user set is in a beam coverage area of a first antenna group in the sector but is not in a beam coverage area of a second antenna group of the sector, and a user equipment in the second user set is in the beam coverage area of the second antenna group but is not in the beam coverage area of the first antenna group (101); and selecting, when a scheduled user equipment belongs to the first user set, an unscheduled user equipment in the second user set for pairing.

Abstract: A transmitting/receiving system may include a transmission line, a transmitter circuit configured to transmit a clock to the transmission line and to adjust an amplitude of the clock in accordance with a logic level of data, and a receiver circuit configured to receive the clock transferred to the transmission line and to recover the data through detection of the amplitude of the clock.

Abstract: A method of performing digital pre-distortion in a communication network is described. The method comprises implementing a transceiver in the communication network, the transceiver enabling the transfer of communication signals in the communication network by way of a wireless communication channel; sampling signals, at the transceiver, associated with a transmit signal which are necessary to perform digital pre-distortion; providing the sampled signals to a remote computer; and generating, at the remote computer, parameters to be applied to a digital pre-distortion circuit of the transceiver. A communication network configured to enable digital pre-distortion is also described.

Abstract: Acquiring a satellite signal, by, receiving a CDMA-modulated signal; generating a plurality of CDMA-type test signals comprising a reference test signal having a first chip duration, and a plurality of test signals delayed/anticipated of a corresponding time offset from the respective test reference signal, less than the chip duration; calculating correlations between the CDMA-modulated signal and the plurality of test signals for obtaining a plurality of correlation results; selecting, based on the correlation results, acquisition parameters associated to a candidate satellite signal; acquiring or rejecting the acquisition parameters selected based on the correlation results.

Abstract: The disclosure provides a technique of enabling to confirm the state of a partner apparatus in high-speed serial communication. An information processing apparatus including a master and a slave which is connected with the master by a plurality of signal lines to be able to make serial communication therewith, the master comprises: a decision unit configured to decide a change in signal level of a data signal line, and a switching unit arranged between the data signal line and the decision unit, and configured to switch whether to invert a logical value based on the fact that the decision unit has decided a change in signal level of the data signal line.

Abstract: A method of predistorting an input signal (902) for an amplifier is disclosed (FIG. 9). The method includes predistorting the input signal with a first set of parameters (FDPD) and a second set of parameters (CDPD) at a first time (904). The first set of parameters is updated at a second time (914). The second set of parameters is updated separately from the first set of parameters at a third time (920).

Abstract: In a Multiple Input Multiple Output (MIMO) system, an apparatus and method includes a Tightly Coupled Array antennas (TCA) or Current Sheet Antennas (CSA). Far-field radiation patterns from any current sheet antenna are formed from the combination of the fields generated by a set of currents on the CSA of array port orthogonal modes, such as the Characteristic Modes (CM). The CM currents are generated by excitation of the CSA element ports with corresponding orthogonal voltages or currents (eigenvectors). Since the radiation patterns of the characteristic modes are orthogonal and uncorrelated, multiple signals may be propagated along the radiation patterns of the characteristic modes, each signal using a different characteristic mode or a different set of characteristic modes. Therefore, a CSA antenna utilizing array port orthogonal modes such as array port characteristic modes can support MIMO communications despite the strong mutual coupling among the antenna elements.

Abstract: The present invention discloses a signal level decision device to determine the level of a source signal. Said source signal comprises a plurality of source messages along a time axis; each source message corresponds to one of a plurality of normal levels; and each normal level is equivalent to at least one of a plurality of extension levels. The signal decision device comprises: a storage circuit to store the level information of the normal level(s) and the equivalent extension level(s) thereof in connection with some or all of the source messages; a transition parameter calculation circuit to calculate a plurality of transition parameters of the normal level and its equivalent extension level(s) in connection with each of the source messages according to the level information; and a decision circuit to determine the level of each of the source messages according to the plurality of transition parameters.

Abstract: Receivers (500) and methods of adaptively adjusting the receivers based on a received interferer are described. The peak-to-average ratio of a received signal is used to determine the type of interferer. The ratio and interferer type, in addition to the type of on-channel signal, are used to select parameters to adjust the decay time of a peak detector (516), and the threshold and hysteresis of a comparator (518). The peak detector (516) and comparator (518) are used to generate an off-channel flag that indicates the presence of a relatively strong interferer to other modules in the receiver (500). If valid data is not present a default set of parameters is provided. The ratio is determined by dividing the maximum peak over the average or a range of ratios is determined by comparing a scaled value of the average to different scaled values of the peak.

Abstract: A system includes a vehicle and logic that performs predictive pairing of multiple antenna of the vehicle with multiple fixed antenna of a port the vehicle is approaching, the predictive pairing performed using data obtained about the multiple fixed antenna obtained via a satellite, the predictive pairing prioritizing maximum spatial diversity in the pairings of the antenna of the vehicle with the fixed antenna.

Abstract: A method of determining precoding information for beamforming between a sender and a receiver the method includes determining a first precoding vector of a first signal layer based on partial channel state information of a channel between the sender and the receiver. The method also includes determining a first guess vector based on long-term characteristics of the channel between the sender and the receiver. A grouping of antennas of the sender is defined and a phase shift value for each group of antennas is specified. The method further includes determining a second precoding vector in the sender of a second signal layer by multiplying each element in the first guess vector with the phase shift value specified for the group of antennas associated with said element in the first guess vector.

Abstract: A method, device and system for complex carrier modulation are provided in the disclosure, wherein e?i?t or ei?t is used as a carrier frequency to perform carrier modulation on a to-be-carried signal. The modulated signal transmitted in a medium is a rotating complex signal. The method can enable right and left frequency bands to carry independent information. Therefore the spectrum utility ratio is improved. Employing the method for complex carrier modulation provided in the disclosure can use the right and left frequency spectrum resources adequately, and the loss of signal energy is small, therefore the capacity of a channel is improved greatly.