Abstract: A radio communication apparatus capable of switching modulation schemes includes a QPSK modulation signal generator configured to modulate transmission data by a QPSK modulation scheme and to output a QPSK modulation signal. A 64QAM modulation signal generator is configured to modulate transmission data by a 64QAM scheme and to output a 64QAM modulation signal. A radio processor is configured to receive, as an input, the QPSK modulation signal or the 64 QAM modulation signal and to output a transmission signal. A transmission power amplifier is configured to amplify a power of the transmission signal. The QPSK modulation signal generator and the 64QAM modulation signal generator perform gain control so as to make an average transmission power of the 64QAM modulation signal smaller than an average transmission power of the QPSK modulation signal.

Abstract: Methods and systems are disclosed for ultra-wideband (UWB) secure wireless device pairing. Secure pairing between devices for secure UWB communications is conducted over in-band UWB communications to provide secure pairing without requiring a visual confirmation through a graphical user interface (GUI), in particular, for wireless personal area network (WPAN) communications. The secure in-band pairing of wireless UWB devices over a UWB radio link provides considerable advantages over prior secure pairing techniques.

Abstract: Method and apparatus to manage delay for multiple receivers for a wireless system are described.

Abstract: A Method to maintain Synchronization Tracking in TDD Wireless Communication comprises the steps: divide a midamble into two parts, then detect the first part and the second part of the midamble; perform an auto-correlation property operation between the two parts and a part corresponding to a local midamble and obtain two peaks; compare the amplitude of the two peaks; advance or retard a local timer based on the result of the comparison. The interlaced sampling method will harm the SNR of channel estimation only very slightly. By using this method, the sample frequency can be decreased to only one time of the chip rate of a TD-SCDMA system while still maintaining the ability to track the downlink synchronization.

Abstract: A transceiver module can share a common connector with a rechargeable battery connection. The transceiver module can be protected from the high voltages applied by a battery charger. Determining when the voltage applied at a connector exceeds a reference voltage and electrically decoupling the transceiver module from the connector when the reference voltage is exceeded can protect the transceiver module. The reference voltage can be set at a level so that the transceiver is decoupled from the connector when the voltage at the connector reaches a voltage that is unsafe for the transceiver.

Abstract: In a multivalue modulation type with one pilot symbol inserted for every 3 or more symbols, signal points of each one symbol immediately before and after a pilot symbol are modulated using a modulation type different from that for pilot symbols. In this way, it is possible to suppress deterioration of the accuracy in estimating the reference phase and amount of frequency offset by pilot symbols and improve the bit error rate characteristic in the signal to noise ratio in quasi-coherent detection with symbols whose symbol synchronization is not completely established.

Abstract: A wireless communication system is configured for adaptive modulation of a transmitted symbol. The specific modulation and/or coding is uniquely identified and data related thereto is embedded within the transmitted symbol. A receiver extracts pilot signals form the transmitted symbol and performs a correlation analysis to identify the particular modulation/coding used for that particular transmitted symbol. This permits adaptive modulation on a symbol-by-symbol basis. A base station communicating with a plurality of peripheral subscribers may utilize different modulation/coding for each subscriber depending on channel conditions.

Abstract: An embodiment and method of the present invention includes a frequency lock loop (FLL) having an improved frequency error estimation and a low bit error rate (BER) in data demodulation by calculating and using an improved averaged phase rotation using ‘valid’ phase rotation samples.

Abstract: An amplifying method and apparatus generates a plurality of constant envelope signals from an input signal and generates a plurality of pilot signals associated with the generated plurality of constant envelope signals, respectively. The plurality of pilot signals have predetermined amplitudes, predetermined phases, and predetermined frequencies, respectively, and the phases and frequencies are different from each other. The plurality of pilot signals are added to the generated plurality of constant envelope signals, and the sum is amplified. An amplitude or phase of one of the generated plurality of constant envelope signals is corrected using signal components included in the amplified plurality of constant envelope signals.

Abstract: A method of determining a synchronous phase includes receiving a correlation sequence, and selecting one or more correlated signals from the correlation sequence. Then, when the number of selected correlated signals is odd, the synchronous phase corresponding to a central correlated signal is selected.

Abstract: Various embodiments of methods and apparatus to remove or reduce phase noise in a baseband signal at a receiver are generally described herein. Other embodiments may be described and claimed.

Abstract: The present invention provides a method and circuit for equalizing and compensating IQ imbalance at the same time. The method includes: down-converting an RF signal to generate a baseband signal, and driving an adaptive equalizer to process the baseband signal for achieving equalization and IQ imbalance compensation simultaneously.

Abstract: Described are communication systems that convey differential and common-mode signals over the same differential channel. Noise-tolerant communication schemes use low-amplitude common-mode signals that are easily rejected by differential receivers, thus allowing for very high differential data rates. Some embodiments employ the common-mode signals to transmit backchannel signals for adjusting the characteristics of the differential transmitter. Backchannel control signals are effectively conveyed even if the forward channel transmitter is so maladjusted that the received differential data is unrecognizable. Systems in accordance with the above-described embodiments obtain these advantages without additional pins or communications channels, and are compatible with both AC-coupled and DC-coupled communications channels. Data coding schemes and corresponding data recovery circuits eliminate the need for complex, high-speed CDR circuits.

Abstract: Some demonstrative embodiments of the invention include a method device and/or system of secure communication in a wireless network using a spatial division multiple access transmission scheme. The method, according to some demonstrative embodiments may include allocating transmission power to N channels to be transmitted to one or more destination stations by N antennas, such that the power to be received by each one of the one or more destination stations is not greater, by more than a predefined power margin, than a minimum power required for reception at a desired quality of service. Other embodiments are described and claimed.

Abstract: A method and system for determining amplitude and phase compensation values used to adjust the amplitude and phase characteristics of real and imaginary signal components of complex signals processed by an analog radio transmitter. The compensation values may be determined in response to detecting a significant temperature change in the transmitter. Corresponding amplitude and phase adjustment signals having levels that correspond to the compensation values are provided to respective amplitude and phase imbalance compensation modules to adjust the amplitude and phase characteristics of at least one of the real and imaginary signal components.

Abstract: In a digital receiver for receiving COFDM modulated television signals or the like, consecutive samples are compared with a detection threshold and the number of samples having amplitudes greater than the threshold is determined. This is compared with a further threshold and, if the number of such samples exceeds the further threshold, affected samples are blanked to zero. Similarly, an automatic gain control loop is disabled when the samples are blanked. A demodulator forms the difference in phase of pilot carriers from symbol to symbol. If the variance of the phase differences exceeds an averaged value, this indicates the presence of impulsive noise and is used to inhibit signal correction techniques within the demodulator. Noise energy is thus reduced and propagation of effects resulting from impulsive noise from symbol to symbol is substantially reduced.

Abstract: A method for allocating a subchannel in a transmitter of an Orthogonal Frequency Division Multiple Access (OFDMA) cellular communication system in which an entire frequency band includes a plurality of bands, each of the bands includes a plurality of bins, and each of the bins includes a plurality of subcarriers. The method includes dividing a predetermined time interval into an Adaptive Modulation and Coding (AMC) subchannel time interval and a diversity subchannel time interval; selecting any one of the plurality of bands in the AMC subchannel time interval; selecting a predetermined number of bins among the plurality of bins in the selected band; and allocating the selected bins to the AMC subchannel.

Abstract: Some demonstrative embodiments of the invention include a method device and/or system of secure communication in a wireless network using a spatial division multiple access transmission scheme. The method, according to some demonstrative embodiments may include generating a set of N spatial channels to be transmitted, using a set of N respective antennas, to a set of K destination stations, by applying at least one precoding matrix to a set of inputs including K transmissions intended to the K destination stations, respectively, and one or more dither sequences, wherein the precoding matrix includes K beamforming vectors based on channel state information of the K stations, respectively, and one or more additional vectors orthogonal to the beamforming vectors. Other embodiments are described and claimed.

Abstract: A method of transmitting data signals from at least two transmitting terminals to at least one receiving terminal with a spatial diversity antenna comprises transmitting from the transmitting terminals transformed data signals, being transformed versions of the data signals; receiving on the spatial diversity means received data signals being at least function of at least two of the transformed data signals; subband processing of at least two of the received data signals in the receiving terminal; and determining estimates of the data signals from subband processed received data signals in the receiving terminal.

Abstract: A method of parallel suppression of interference, and corresponding stage and receiver is disclosed according to the invention, parallel suppression of interference is carried out starting from the signals selected by a maximum likelihood criterion based on the calculation of a metric and the search for the smallest possible metric.