Abstract: A system that incorporates teachings of the subject disclosure may include, for example, a method for identifying a spectral region in a radio frequency spectrum for initiating a communication session having a transmission link and a reception link, determining a correlation factor from signals measured in the spectral region, detecting according to the correlation factor a foreign communication signal in the spectral region, generating coefficient data to prevent interference with the foreign communication signal while transmitting in the transmission link, filtering a first signal for transmission in the transmission link according to the coefficient data to generate a filtered signal, and causing a transmission of the filtered signal which prevents interference with the foreign communication signal while transmitting in the transmission link. Other embodiments are disclosed.

Abstract: Embodiments include circuit devices and methods for re-clocking an input signal. In an embodiment, a circuit device includes a data storage element having a data input to receive a digital data stream having a first clock rate and including a clock input to receive a clock signal having a second clock rate. The data storage element further includes logic to adjust edge timing of transitions within the digital data stream based on the clock signal to produce a modulated output signal having a power spectrum with spectral nulls at a desired frequency and its harmonics without changing an average data rate.

Abstract: Embodiments of a method and apparatus for selecting one of several different power constraints under which sets of complex, beam weights are normalized are described herein. The embodiments of the method and apparatus specifically select the power constraint based on a code rate used to encode information carried by a transmit signal weighted by the sets of complex, beam weights. Appropriate selection of the power constraint can improve the bit error rate (BER) or block error rate (BLER) of the decoded transmit signal at a receiver.

Abstract: A communication terminal may include a receiver configured to receive data via a first channel or via a second channel; and a controller configured to control the receiver such that it receives a part of first data from a first facility of a first network by means of the first channel in a first part of a period in which the transmission of the first data by the first facility overlaps the transmission of the second data by the second facility and that the receiver receives a part of the second data from the second facility by means of the second channel during a second part of the period so that the first part of the period and the second part of the period do not overlap and so that the part of the first data which is received in the first part of the period meets a predetermined criterion.

Abstract: An interference cancellation technique is implemented in a receiver adapted for determining an estimation of interferences when receiving an OFDM signal made of packets. Each packet includes a first training field, a second training field, a first header field, a second header field and a data field. The receiver detects a first symbol value of the first header field, and a second symbol value of the second header field, the first and the second header fields having been modulated using different modulation schemes. The estimation of interferences is determined using the first and the second symbol values.

Abstract: A method of detecting a transmission. The method includes: measuring, from a first portion of a received spread-spectrum signal, a first code-phase of a spreading-code; measuring, from a second portion of the signal, a second code-phase of the spreading-code; comparing the first and second code-phases; and detecting whether the transmission is present according to the result of the comparison. Also disclosed are corresponding methods and apparatus for transmission and reception of signals.

Abstract: In accordance with the teachings described herein, system and methods are provided for a GPS PRN code interpolation scheme with a reduced memory requirement. An example GPS receiver system may include a memory, a local PRN code generator, and an interpolator. The memory may be used to store GPS PRN code received from a global positioning satellite. The local PRN code generator generates a replica PRN code having a repeating code that includes at least a first epoch and a second epoch. The interpolator determines an offset point in the first epoch of replica PRN code and interpolates the replica PRN code at a predetermined sample rate to generate an interpolated replica PRN code for use in correlating with the GPS PRN code.

Abstract: A method for detecting a preamble in a received radio signal includes demodulating the radio signal based on a carrier derived from a local timing source to provide a digital signal including a sequence of bits oscillating at approximately a modulated data rate. A bit width of each successive bit of the digital signal is determined. If a pair of consecutive bit widths has a combined width within a threshold, the bit pair is indicated as potentially belonging to a preamble. If a threshold number of potential preamble bit pairs in a sequence of bit pairs within a given window is detected, the sequence of bit pairs is indicated as potentially belonging to a preamble. A measure of bit widths of at least some bits within a sequence of preamble bit pairs can be provided and a frequency of the local timing source can be adjusted according to the measure.

Abstract: A method and corresponding receiver product, the method including: receiving a plurality of data streams over a wireless multiple-input-multiple-output data channel, whereby each data stream is received at all of a plurality of receive antennas from all of a plurality of transmit antennas with a respective weighting having been applied to each stream as transmitted from each different transmit antenna; receiving a common pilot signal over a common pilot channel; receiving an indication of the weightings; extracting the individual data streams from the plurality received at the receive antennas; and using the weightings and the common pilot signal together with information regarding the extracted data streams to calculate, for each of the streams, an estimate of signal power relative to interference from the one or more others of the data streams.

Abstract: A signal transmission device includes: at least one of a first communication device that transmits a control signal as a wireless signal and a second communication device that receives the wireless signal transmitted from the first communication device to reproduce the control signal, wherein the wireless signal for the control signal is transmitted separately from a wireless signal for a transmission subject signal which is transmitted between a third communication device and a fourth communication device.

Abstract: A VCO of a PLL outputs a first differential signal of frequency FVCO. A first divide-by-two circuit local to the VCO divides the first differential signal and outputs a first quadrature signal of frequency FVCO/2. Two of the component signals of the first quadrature signal are routed to a second divide-by-two circuit local to a first mixer of a first device. The second divide-by-two circuit outputs a second quadrature signal of frequency FVCO/4 to the first mixer. All four signals of the first quadrature signal of frequency FVCO/2 are routed through phase mismatch correction circuitry to a second mixer of a second device. In one example, FVCO is a tunable frequency of about ten gigahertz, the first device is an IEEE802.11b/g transmitter or receiver that transmits or receives in a first band, and the second device is an IEEE 802.11a transmitter or receiver that transmits or receives in a second band.

Abstract: Embodiments of millimeter-wave transceivers with coarse and fine beam steering with interference suppression are generally described herein. In some embodiments, a millimeter-wave transceiver configured for multipath reception of multicarrier signals and includes RF circuitry to receive multicarrier signals through at least two independently controllable sub-arrays from first and second directions, a channel-estimation block to generate a set of weighting coefficients for each sub-array based on channel characteristics determined from each sub-array, the weighting coefficients generated for inter-channel interference (ICI) suppression, and maximum-ratio combining (MRC) circuitry to apply a set of the weighting coefficients to baseband signals from each sub-array and to combine the weighted baseband signals from each sub-array to generate combined baseband signals that represent a single data stream.

Abstract: In an embodiment, a channel estimator includes first, second, and third stages. The first stage is configurable to generate a first observation scalar for a first communication path of a first communication channel, and the second stage is configurable to generate a second observation scalar for a first communication path of a second communication channel. And the third stage is configurable to generate channel-estimation coefficients in response to the first and second observation scalars. For example, such a channel estimator may use a recursive algorithm, such as a Vector State Scalar Observation (VSSO) Kalman algorithm, to estimate the responses of channels over which propagate simultaneous orthogonal-frequency-division-multiplexed (OFDM) signals (e.g., MIMO-OFDM signals) that suffer from inter-carrier interference (ICI) due to Doppler spread.

Abstract: An embodiment of a receiver includes a channel estimator and a data-recovery unit. The channel estimator is configured to determine a characteristic of a channel over which a first signal, which is received simultaneously with a second signal, propagated, the first and second signals respectively having first and second components that include approximately a frequency. And the data-recovery unit is configured to recover data from the first signal in response to the determined channel characteristic. For example, such a receiver may be able to receive simultaneously, and over the same channel space, orthogonal-frequency-division-multiplexed (OFDM) signals that include one or more of the same subcarrier frequencies, and to recover data from one or more of the OFDM signals despite the frequency overlap. A receiver with this capability may allow an increase in the effective bandwidth of the channel space, and thus may allow more devices to simultaneously share the channel space.

Abstract: In an embodiment, a channel estimator includes first and second stages. The first stage is configurable to generate an observation scalar for a communication path of a communication channel, and the second stage is configurable to generate channel-estimation coefficients in response to the first observation scalar. For example, such a channel estimator may use a recursive algorithm, such as a VSSO Kalman algorithm, to estimate the response of a channel over which propagates an OFDM signal that suffers from ICI due to Doppler spread. Such a channel estimator may estimate the channel response more accurately, more efficiently, with a less-complex algorithm, and with less-complex software or circuitry, than conventional channel estimators. Furthermore, such a channel estimator may be able to dynamically account for changes in the number of communication paths that compose the channel, changes in the delays of these paths, and changes in the signal-energy levels of these paths.

Abstract: This technique relates to a receiving device, a receiving method, a program, and a receiving system that are designed to reduce circuit size. A receiving device of one aspect of this technique includes: a de-mapping unit that receives a symbol signal generated by performing mapping on a first branch signal and a second branch signal indicating information about the same transmission target, and performs de-mapping on the symbol signal by a hard decision; a selecting unit that selects, in accordance with a reception state, one signal from the first branch signal and the second branch signal obtained through the de-mapping; and a decoding unit that decodes the information about the transmission target based on the one signal. This technique can be applied to receivers that receive OFDM signals compliant with DVB-C2.

Abstract: Block-encoded transmissions of a multi-antenna terminal unit are effectively detected in the presence of co-channel interfering transmissions when the base station has a plurality of antennas, and interference cancellation is combined with maximum likelihood decoding. More specifically, the signals received at the base station antennas are combined in a linear combination that relates to the channel coefficients between the various transmitting terminal units and the base antennas. By selecting proper coefficients for the linear combination and choosing probable transmitted signals that minimize a minimum mean squared error function, the signals of the various terminal units are canceled when detecting the signal of a particular unit. In another embodiment of the invention, the basic approach is used to obtain an initial estimate of the signals transmitted by one terminal unit, and the contribution of those signals is removed from the received signals prior to detecting the signals of other terminal units.

Abstract: A transceiver, a method of providing multiple-band virtual concurrent wireless communication and a wireless device incorporating the transceiver or the method. In one embodiment, the transceiver includes: (1) first transmit and receive intermediate frequency (IF) strips, (2) second transmit and receive IF strips, (3) first and second local oscillators (LOs) and (4) switches operable to multiplex clock signals from the first and second local oscillators to cause the transceiver to operate in a selectable one of: (4a) a unified, multiple-input, multiple-output (MIMO) mode in which the first and second transmit and receive IF strips are driven to transmit and receive in a first band and (4b) a concurrent multiple-band connection mode in which the first transmit and receive IF strips are driven in the first band and the second transmit and receive IF strips are concurrently driven in a second band.

Abstract: Briefly, in accordance with one or more embodiments, a base transceiver station having a first set of antennas and a second set of antennas geographically separated from the first set of antennas transmits a reference signal to a first device, and receives feedback from the first device. The feedback represents information that can be used to construct a weight adjustment vector. The base transceiver station selects a precoding vector from a codebook based at least in part on the feedback received from the first device, calculates the weight adjustment vector based at least in part on the feedback, and applies the weight adjustment vector to the selected precoding vector to provide an adjusted precoding vector. The base transceiver station then may transmit data to the first device using the adjusted precoding vector.

Abstract: An approach includes injecting a plurality of equal amplitude tones across a frequency band. The approach also includes determining frequency response based on the injected tones, determining an imbalance parameter associated with a quadrature down-converter based on the determined frequency response; determining one or more parameters for wideband quadrature compensation based on the determined frequency response, and compensating an input signal based on the determined imbalance parameter and the determined one or more parameters for the wideband quadrature compensation.