Abstract: A VCSEL array device formed of a monolithic array of raised VCSELs on an electrical contact and raised inactive regions connected to the electrical contact. The VCSELs can be spaced symmetrically or asymmetrically, in a manner to improve power or speed, or in phase and in parallel. The raised VCSELs and raised inactive regions are positioned between the electrical contact and an electrical waveguide. The VCSELs may be separated into subarrays and each VCSEL may be covered with an integrated or bonded microlens for directing light without external lenses. The microlenses may be offset to collect or collimate light and may be shaped to form various lens profiles.

Abstract: Techniques and architecture are disclosed for providing a laser system. In one specific example embodiment, the system includes a thulium-doped fiber laser coupled by silica glass fiber to a remote optical converter (ROC) including a Ho:YAG laser and, optionally, an optical parametric oscillator (OPO) utilizing zinc germanium phosphide (ZnGeP2; ZGP) or orientation-patterned gallium arsenide (OPGaAs). The fiber laser may emit a low-peak-power, continuous wave pump signal that pumps the Ho:YAG laser, which in turn emits a higher-peak-power, pulsed signal. When included, the OPO can be used to convert the resultant, pulsed signal to a longer wavelength (e.g., about 2-5 ?m, or greater). In some cases, distributed architecture and reduced weight/bulk may be realized while eliminating the need to actively cool the ROC for operation, for example, over a broad temperature range (e.g., ?55-125° C.). Also, methods of preparing high-peak-power, pulsed signals using such systems are disclosed.

Abstract: A tunable DBR laser including: an amplifier section, a part-reflecting optical output, a connection section connected to the amplifier section, and at least two wavelength-selective reflectors optically coupled to the amplifier section via the connection section. The connection section includes at least one MMI coupler and several waveguides, so that different optical paths lead from the amplifier section to the wavelength-selective reflectors and each of the different optical paths leads through the at least one MMI coupler and through one of the waveguides. The wavelength-selective reflectors differ from one another by having different reflection spectra and each of the wavelength-selective reflectors is connected to one of several outputs of the at least one MMI coupler. By activating a phase shifter, arranged in a course of at least one of the waveguides, the DBR laser can be switched between different resonators.

Abstract: A method to estimate parameters of a system to spread a spectrum of a first periodic signal according to a modulation period. An embodiment comprises sampling the first signal using a second periodic signal, determining based on the sampling result each occurrence where the first and second signals are synchronous, incrementing a first counter at each sampling, the first counter being reset at each said occurrence, storing at each said occurrence the last value of the first counter before the resetting, providing a third periodic signal at a first level when said last value is greater than a threshold and at a second level when said last value is smaller than the threshold, and determining the modulation period based on the period of the third signal.

Abstract: The invention relates to a method for operating a secondary station, the secondary station communicating with at least one primary station by means<MIMO transmissions, the method comprising the secondary station signaling a single precoding indicator representative of a set of recommended precoding coefficients to the primary station, wherein the same precoding indicator applies for a plurality of available transmission modes.

Abstract: An apparatus and method for a two-stage linear/nonlinear interference cancellation comprising processing a receive signal to produce a first descrambled signal; and processing the first descrambled signal to produce a detected signal. In one aspect, a first interference canceller module is used for processing the received signal and a second interference canceller module is used for processing the first descrambled signal. In one aspect, the first interference canceller is a linear interference canceller (IC) and the second interference canceller is a linear/nonlinear interference canceller (IC).

Abstract: In one aspect, the teachings herein disclose a method and apparatus for signal quality reporting from a wireless apparatus that better reflects the actual interference cancellation efficiency expected at the wireless apparatus for a given transmission interval. In one example, the wireless apparatus knows or predicts the particular modulation and coding schemes (MCSs) that will be used in the transmission of one or more interferer signals for a transmission interval of interest. In turn, it uses those MCS values to estimate the actual interference cancellation efficiency the wireless apparatus will achieve with respect to those interferers. The wireless apparatus estimates and reports signal quality according to its estimated interference cancellation efficiency.

Abstract: An asynchronous correlation circuit includes a first data supply unit that dual-rail-encodes first sequence data and supplies first data to be provided for next calculation at each time when calculation is completed, a second data supply unit that dual-rail-encodes second sequence data and supplies second data to be provided for next calculation at each time when calculation is completed, an addition result storage unit, a third dual-rail encoding unit that dual-rail-encodes a storage value of the addition result storage unit, an asynchronous full addition unit that adds an output value from the first data supply unit to an output value of the third dual-rail encoding unit with a sign in response to an output value from the second data supply unit, and outputs the value, and a dual-rail decoding unit that decodes and outputs an output value of the asynchronous full addition unit to the addition result storage unit.

Abstract: Provided is a physical layer network coding method and apparatus. A relay node determines reliabilities of symbols of nodes, based on a signal received from the plurality of nodes, and generates a transmission signal that maintains reliabilities of symbols that have high reliabilities and excludes components of symbols that have low reliabilities. The relay node generates the transmission signal that reduces an expected power of error, based on the received signal.

Abstract: A transceiver for a cellular telephone network includes a transmitter and a receiver that receives transmitted signals, as well as a receiver. A spectral analyzer analyzes the received signals and a controller coupled to the spectral analyzer controls the transmitter and receiver as a function of the spectral analyzer analysis.

Abstract: An achievable sum data rate with respect to each of available candidate transmission/reception modes may be calculated to select a transmission/reception mode of transmission/reception pairs repeatedly using radio resources. A transmission/reception mode to be applied may be selected from the candidate transmission/reception modes based on the calculated sum data rate. Information associated with the selected transmission/reception mode may be shared by the transmission/reception pairs.

Abstract: In an embodiment, a communication device is provided comprising transmit circuitry and crosstalk reduction circuitry. In an embodiment, the crosstalk reduction circuitry is configured to receive crosstalk information indicative of crosstalk between a plurality of communication connections for only a part of communication channels of said communication connections.

Abstract: Techniques for providing a transceiver with a sliding intermediate frequency (IF). In an aspect, a PLL generates a single local oscillator (LO) signal used for both up-conversion by a transmit (TX) signal path and down-conversion by a receive (RX) signal path, wherein the LO frequency is chosen as the TX carrier frequency. As the TX and RX carrier frequencies may generally differ by a variable amount, the RX signal path utilizing the (TX) LO frequency for down-conversion may be characterized as having a “sliding” IF. To accommodate the sliding IF receiver architecture, specific processing functions such as charge sampling, discrete-time analog band-pass filtering, and sub-sampling analog-to-digital conversion (ADC) are described.

Abstract: Disclosed is a transceiver including a sub-sampling based frequency synthesizer with a sampling frequency fsmp, configured to generate M different output signals 3 for use as a carrier signal for transmission and/or a signal with a channel frequency for reception. M is an integer greater than 4, each output signal has a corresponding predefined frequency. The predefined frequencies are within a frequency band with a predefined bandwidth CFR. CFR is greater than fsmp. The frequency synthesizer includes a frequency shift unit configured for shifting a version of the output signal over a predefined frequency shift fshift to obtain a frequency shifted signal which is supplied to a sampling unit of the sub-sampling based frequency synthesizer, wherein ?fsmp/2?fshift?+fsmp/2. The frequency shift unit is configured to use for the generation of each of the N different output signals a corresponding predefined frequency shift fshift.

Abstract: Transceiver self-diagnostics for electromagnetic interference (EMI) degradation in balanced channels. Selective operation of transmitting a common mode signal from a communication link implemented for supporting differential signaling, and appropriate processing of any detected signal energy, such as that corresponding to differential signal energy, provides a measure of electromagnetic compatibility (EMC) corresponding to the communication link. Comparison of detected differential signal energy to one or more thresholds may provide indication of whether or not the communication link is balanced or unbalanced, a degree or margin with which the communication link is compliant in accordance with EMC in accordance with one or more protocols, standards, or recommended practices. Multiple successive measurements of detected differential signal energy may be used to determine a trend of performance, such as whether or not the communication link is trending toward imbalance, failure, or noncompliance.

Abstract: Transmitting and receiving arrangements and methods in a Digital Subscriber Line (DSL) system having a plurality of modems and vectored transmission capability. A first part of an available frequency band is reserved exclusively for vectored DSL transmission and reception using modems operating in the first part of the frequency band. The remaining, second, part of the available frequency band is reserved for both vectored and non-vectored transmission using modems operating in the second part of the frequency band.

Abstract: Systems and methods are provided to enable a near-end receiver to control the far-end transmitter's data transmission such that the near-end receiver's TC data buffers do not overflow. In an embodiment, a high waterline and low waterline implemented into a near-end receiver are used to determine when the near-end receiver's TC data buffers are near maximum capacity. In an embodiment, the near-end receiver transmits a Packet Transfer Mode (PTM) All Idle Out Of Sync (AIOOS) codeword to the far-end transmitter when the high waterline is reached, and the near-end receiver stops transmitting the AIOOS codeword when the low waterline is reached.

Abstract: A portion of a signal under test corresponding to a portion of interest in an eye pattern is easily identified. An eye pattern display area displays an eye pattern that is derived from sample data of a signal under test in a bitmap form and shows frequency information with colors or brightness. A user selects an arbitrary point on the eye pattern display area with a cross-hair shaped mouse cursor, by manipulating a mouse. Thereafter, a waveform passing through the selected point is discriminably displayed, for example, with highlighted display on the eye pattern. Further, the corresponding portion of a waveform in the waveform display area is distinguishably displayed, such as with a highlighted display.

Abstract: The present invention relates to techniques for OTA testing suitable for producing a test signal to emulate a wireless channel while using a limited number of transmit elements. The techniques described herein enable the number of transmit antennas used to emulate a given signal path in an emulated wireless channel to be less than the number of sub-paths used to characterize the angle spread of the given signal path. As a result, a test setup is provided having a relatively small number of transmit antennas which also accurately maintaining the desirable characteristics of the emulated wireless channel.

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: Device and method for outputting a leaked radio frequency (RF) signal useable for triggering devices under test (DUTs). The device may include a vector signal analyzer (VSA) which may also perform the method for triggering DUTs. The VSA may include a first component, configured to generate an RF signal, an input configured to receive RF signals transmitted from DUTs, and a received RF signal conditioning portion, each coupled to an internal switching portion. The VSA may be configured to generate the RF signal via the first component, leak the RF signal from the first component to the internal switching portion, generating a leaked RF signal, route the leaked RF signal to the input, bypassing the received RF signal conditioning portion and output the leaked RF signal which is useable to trigger DUTs via the input.

Abstract: A method of analyzing a phase of a clock signal for receiving data is described. The method comprises identifying an end of an eye pattern associated with received data; testing points along a contour of the eye pattern to establish a margin for an opening of the eye pattern; and determining whether a phase of the clock signal is acceptable for receiving the received data. A circuit for analyzing a phase of a clock signal for receiving data is also described.

Abstract: Techniques for performing channel estimation in an orthogonal frequency domain multiplexing (OFDM) communications system include receiving a plurality of reference signals on a plurality of subcarriers, performing channel estimation to obtain a plurality of raw channel estimates based on the received plurality of reference signals, determining a number of raw channel estimates to be used for a channel estimate refinement and calculating a refined channel estimate using the number of raw channel estimates from the plurality of raw channel estimates.

Abstract: Access terminals are adapted to facilitate estimation of signal-to-noise ratios for received wireless transmissions. According to at least one example, a wireless communication device can receive a plurality of data symbols. The wireless communication device can determine a first estimate of a signal-to-noise ratio based on first estimates of a signal power and a noise power associated with the plurality of received data symbols. When the first estimate of the signal-to-noise ratio is below a predetermined threshold, a second estimate of the signal-to-noise ratio can be determined based on second estimates of the signal power and the noise power for the received data symbols. Other aspects, embodiments, and features are also included.

Abstract: The present invention relates to a device for the location of passive intermodulation faults in a coaxial cable network. The test apparatus (100) according to one embodiment of the present invention utilizes a pair of high-power, frequency-synthesized, unmodulated RF carriers v1(t) (101) and v2(t) (102) are generated inside the HPA module of the apparatus. The power and frequency of v1(t) (101) and v2(t) (102) can be independently set to a range of values, v1(t), v2(t) are combined inside the instrument and then applied to the input of the device under test (DUT). The PIM signals (107,108,109) generated in the DUT are combined to produce the primary PIM signal vIM(t) (103). The apparatus also includes two receivers (110,111, 112,113,114,115) for the detection of vIM(t) 103 and vREF(t) (104). These signals are downconverted to 455 kHz.

Abstract: Apparatus and methods mitigate a problem of equalizing communications signals that have been distorted by severe non-linearities such as clipping or harsh compression. For example, severe non-linearity occurs when signal compression or signal clipping occurs at rates above 20% of the data transmission interval. Severe non-linearities may significantly reduce system performance. Disclosed techniques selectively apply DSP equalization based on the detection of non-linearity for a present sample or one or more samples prior to the present sample. These techniques can be implemented in relatively low-cost high-speed SerDes designs to improve eye openings and reduce sensitivity to InterSymbol Interference (ISI) and to improve bit error rate (BER).

Abstract: Generating updated coefficients for an adaptive equalizer involves generating phase tracking information using asynchronous detection strategy (ADS) based on resolved data, and equalized signals, and estimating a phase corrected error based on the equalized signals, the phase tracking information and the resolved data. An inhibit signal is generated to inhibit updating of the equalization coefficients, the inhibit signal representing a likelihood of the phase corrected error being accurate, determined according to the phase corrected error, and the equalized signals. The equalization coefficients for the equalizer are adapted based on the received signals, and on the phase corrected error, and the adapting is inhibited according to the inhibit signal. Compared to conventional ADS, the new combination with the inhibit signal can enable improved convergence of coefficient adaptation. This is particularly useful for coherent receivers for optical systems.

Abstract: In particular embodiments, a method includes receiving as an input signal a phase-distorted signal or a transmitted-data signal, the phase-distorted signal having been distorted from a phase-equalized signal by transmission across a communication channel, the transmitted-data signal comprising transmitted data; generating a non-derivative version of the input signal by applying a delay operator in a continuous-time domain to the input signal; generating a derivative version of the input signal by applying a derivative operator in a continuous-time domain to the input signal; generating a first product signal by multiplying the non-derivative version of the input signal by a first coefficient, the first coefficient being a positive number; generating a second product signal by multiplying the derivative version of the input signal by a second coefficient, the second coefficient being a negative number; and generating an output signal by summing the first and second product signals.

Abstract: A method and system for high density pulse density modulation is disclosed. In accordance with the present disclosure, a modulation function is split in to two band limited streams using a complementary pair of non-linear functions. More specifically, one bitstream definition contains the peaks of the original function while the other bitstream contains a soft clipping version of the original bitstream. The bitstreams are applied to a pair of switching amplifiers, and the bitstreams can be combined again to reconstruct the original function. The method in accordance with the present disclosure limits the amount of input power necessary to achieve higher output power, lowers operating voltage and improves power amplifier efficiency.

Abstract: A method and system are provided for encoding a picture. The method includes encoding the picture into a first encoded picture using a first universal quantizer. If a size of the first encoded picture is greater than a maximum picture size, the method includes encoding the picture into a second encoded picture using a second universal quantizer. Before a second-pass encoding, the target size and maximum size for each slice is determined. During the second pass encoding, if a size of the encoded slice is greater than the maximum slice size, the method includes encoding the slice using a third local quantizer. If a size of the encoded slice is still greater than a maximum slice size, the method includes dropping coefficients from the encoded slice to ensure that the encoded size never exceeds the maximum size.

Abstract: In an example, aspects of this disclosure relate to a method of coding video data that includes determining context information for a block of video data, where the block is included within a coded unit of video data, where the block is below a top row of blocks in the coded unit, and where the context information does not include information from an above-neighboring block in the coded unit. That method also includes entropy coding data of the block using the determined context information.

Abstract: An example image decoding apparatus and method involves acquiring encoded data including an image code sequence corresponding to a slice of a plurality of slices obtained by dividing a picture of a moving image and first timing information indicating a first time at which the slice is to be decoded and no underflow or overflow occurs in a first virtual reception buffer from which the image code sequence is output in a slice unit. The image code sequence is decoded on the basis of the first timing information.

Abstract: To increase efficiency of a bit-depth scalable data-stream an inter-layer prediction is obtained by mapping samples of the representation of the picture or video source data with a first picture sample bit-depth from a first dynamic range corresponding to the first picture sample bit-depth to a second dynamic range greater than the first dynamic range and corresponding to a second picture sample bit-depth being higher than the first picture sample bit-depth by use of one or more global mapping functions being constant within the picture or video source data or varying at a first granularity, and a local mapping function locally modifying the one or more global mapping functions and varying at a second granularity smaller than the first granularity, with forming the quality-scalable data-stream based on the local mapping function such that the local mapping function is derivable from the quality-scalable data-stream.

Abstract: In one aspect of this disclosure, techniques are described for the decoupling of uni-directional and bi-directional prediction weights, particularly for explicit weighted predictions of video blocks within a B-unit. According to this disclosure, explicit weights communicated in the bitstream may be applied by a decoder for explicit bi-directional prediction, but different weights (which may be default weights or separately defined explicit uni-directional weights) may be used for explicit uni-directional prediction. The described techniques may improve video quality relative to techniques that use the same explicit weights for explicit bi-directional prediction and explicit uni-directional prediction within a B-unit.

Abstract: In one example, this disclosure describes video encoding and decoding techniques applicable to bi-directional prediction. For signaling from an encoder to a decoder a block type for a video block, an encoder can transmit to the decoder two or more separate syntax elements, where one of the two or more separate syntax elements identifies a partition size for the video block and another of the two or more separate syntax elements identifies a prediction direction for a partition of the video block. The separate syntax elements can be individually encoded and transmitted from the encoder to the decoder.

Abstract: Coding techniques for a video image compression system involve improving an image quality of a sequence of two or more bi-directionally predicted intermediate frames, where each of the frames includes multiple pixels. One method involves determining a brightness value of at least one pixel of each bi-directionally predicted intermediate frame in the sequence as an equal average of brightness values of pixels in non-bidirectionally predicted frames bracketing the sequence of bi-directionally predicted intermediate frames. The brightness values of the pixels in at least one of the non-bidirectionally predicted frames is converted from a non-linear representation.

Abstract: Provided are methods and apparatuses for encoding and decoding a motion vector. The method of encoding a motion vector includes: selecting a mode from among a first mode in which information indicating a motion vector predictor of at least one motion vector predictor is encoded and a second mode in which information indicating generation of a motion vector predictor based on pixels included in a previously encoded area adjacent to a current block is encoded; determining a motion vector predictor of the current block according to the selected mode and encoding information about the motion vector predictor of the current block; and encoding a difference vector between a motion vector of the current block and the motion vector predictor of the current block.

Abstract: A moving image decoding apparatus which enables reduction in the memory bandwidth and the memory access latency for the motion compensation filter coefficients for use in inter-picture prediction involving motion compensation using variable coefficients includes: a decoding unit (101) which decodes, from a coded stream, a plurality of motion compensation filter coefficients; a memory (109) for holding the motion compensation filter coefficients included in the coded stream; a filter coefficient storage unit (103) for holding at least one of the motion compensation filter coefficients which is required for the motion compensation; a motion compensation unit (107) which performs motion compensation using the required motion compensation filter coefficient held in the filter coefficient storage unit; and a filter coefficient transfer control unit (102) which writes, in the memory, the motion compensation filter coefficients decoded by the decoding unit, and transfers the required motion compensation filter coeff

Abstract: Technologies are generally described herein for extracting a representative motion flow from a video. Technologies are also generally described herein for retrieving a video utilizing the representative motion flow. The representative motion flow may be extracted utilizing a sliding window approach to generate interesting motion flows. The representative motion flow may be generated based on the interesting motion flows.

Abstract: Methods of encoding a video stream in a video encoder and decoding an encoded video stream in a video decoder using a low complexity large transform are provided. An encoding method includes receiving an n×n residual block in a transform component of the video encoder, and transforming the n×n residual block using an n×n transform to generate an n×n transform coefficient block, wherein the n×n transform is based on (n/m*n/m) m×m Hadamard transforms and (m*m) (n/m)×(n/m) discrete cosign transforms, wherein m<n. A decoding method includes receiving an n×n transform coefficient block in an inverse transform component of the video decoder, and applying an n×n inverse transform to the n×n transform coefficient block to reconstruct an n×n residual block, wherein the n×n inverse transform is based on (n/m*n/m) m×m Hadamard transforms and (m*m) (n/m)×(n/m) inverse discrete cosign transforms, wherein m<n.

Abstract: A frame header of Forward Error Correction (FEC) is provided, suitable for using in the DVB-C2 Standard. In the DVB-C2 Standard, Adaptive Coding and Modulation (ACM) or Variable Coding and Modulation (VCM) is applied to each FEC block to provide as much flexibility as possible. As a result, a frame header is attached in front of each FEC frame to inform the coding rate, modulation type and physical layer pipe identifier. Besides the signaling of physical layer related information, the FEC frame header has to provide a structure so that it can be easily and reliably detected in the receiver. Motivated by the need in DVB-C2 Standard, an efficient and reliable FEC header suitable for DVB-C2 Standard is provided in at least one implementation in this disclosure that combines use of two different modulation types for the header information. In addition, the detection Method of the FEC header is described.

Abstract: Systems and methods for multimedia encoding and decoding are disclosed. The systems and methods include multimedia format detection systems, decoder functionality generation systems, decoder instantiation systems, and multimedia processing engines which are capable of selecting a decoder or playback mechanism for each input encoded multimedia stream. The functionality of the decoder or playback mechanism is represented as syntax elements which may be further encoded. The functionality for decoding or playback is then stored or transmitted with the multimedia bitstream. Alternatively, the functionality and multimedia bitstream can be embedded in or associated with a second digital bitstream. Further, the functionality associated with an encoded multimedia stream can be used to instantiate a decoder or playback mechanism and the encoded multimedia stream decoded with the instantiated decoder or mechanism.

Abstract: A method for signaling sample adaptive offset (SAO) band offset syntax elements in a video encoder is provided that includes receiving a plurality of band offset syntax elements, entropy encoding an absolute value of a magnitude of each band offset syntax element in a compressed video bit stream, and entropy encoding a sign of each non-zero band offset syntax element in the compressed video bit stream following the absolute values of the magnitudes.

Abstract: Described herein is a system and method for audio visual synchronization. The picture are displayed by receiving an identifier, said identifier associated with a frame buffer storing a picture; extracting a presentation time stamp associated with the picture, wherein the picture is associated with a time stamp; comparing a local time clock value to the presentation time stamp; determining that the picture is mature for presentation if the presentation time stamp exceeds the local time clock value by less than a first predetermined threshold; and determining that the picture is mature for presentation if the local time clock value exceeds the presentation time stamp by less than a second predetermined threshold.

Abstract: The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting uplink control information in a wireless communication system. A method for transmitting uplink control information in a wireless communication system according to one embodiment of the present invention comprises a step of repetition coding information bit of N-bit to generate an encoded bit; and a step of transmitting the encoded bit via a physical uplink shared channel, wherein bit inversion can be applied to the bit obtained by repeating the information bit of N-bit, on the basis of the number 1 contained in the information bit of N-bit.

Abstract: An apparatus is capable of distributing power over a number of subcarriers in an OFDM system. The transmission power control method for an Orthogonal Frequency Division Multiplexing (OFDM) communication system according to the present invention includes measuring, at a receiver, channel coefficients of subcarriers, classifying the subcarriers into a predetermined number of groups according to sizes of channel coefficients, generating group indices, and transmitting the group indices of the subcarriers to a transmitter. A transmitter is capable of receiving the group indices of the subcarriers, determining per-group transmission powers, allocating the per-group transmission powers to the corresponding groups, distributing the per-group transmission power over subcarriers in the same level within respective groups, and transmitting signals over the subcarriers with the distributed power level.

Abstract: Methods and apparatus for determining, e.g., selecting, communications resources, e.g., tones, to use in a communications system are described. The methods are well suited for use in Orthogonal Frequency Division Multiplexing (OFDM) systems. Devices seeking to transmit information select tones in pairs for use in transmitting the information. Each tone pair includes a tone and the corresponding image tone. By restricting a communications device to select communications frequencies in pairs, the problem of interference and reduced dynamic range at a receiver due to IQ imbalance is reduced, as compared to the case where devices may use a tone independent of the corresponding image tone for transmission purposes, since the path loss from the transmitter to the receiver is likely to be the same for both tones and the transmission power level is controlled by an individual device using both of the tones.

Abstract: To provide a system that can accommodate a greater number of terminals within a limited band and can obtain a higher transmission rate. While the number of frequency signals (spectrums) output in parallel by performing a spread spectrum from the DFT unit of each terminal is 12, the number of sub-carriers constituting one sub-channel is set at 10 or 11. In this case, the users (users A and G) allocated to the sub-channels at both ends of the band will not perform transmission of one frequency signal at the end (one sub-carrier) of all the frequency signals output from the DFT unit, whereas the users (users B to F) allocated to the other sub-channels will not perform transmission of the frequency signals at the ends (two sub-carriers). This transmission can be realized by deleting (clipping) the associated number of signals from both ends or from one end of the frequency signals output from the DFT unit of each terminal and allocating the frequency signals after clipping, to individual sub-channels.

Abstract: A method, mobile terminal, and system for reporting BCI are provided, the method comprises the steps of: obtaining a PMI W1 set and a PMI W2 to be used for a mobile terminal based on a double codebook; computing a BCI W1 set to be used for another mobile terminal based on the PMI W1 set; selecting a BCI W2 from the BCI W1 set based on the PMI W2; and reporting the BCI W1 set and the BCI W2 to a base station, wherein W1 indicates a long-term or wideband component of the PMI and BCI, and W2 indicates a short-term or narrowband component of the PMI and BCI. With the present disclosure, the probability that the optimal BCI W2 is included in the shifted BCI W1 set is increased, and the overhead for feeding-back the BCI is reduced.

Abstract: Various embodiments of the invention are directed to methods and systems for multi transform OFDM transmitter and receivers with low peak to average power ratio (PAPR) signals, that have high bandwidth efficiency and are computational efficient. For example, various embodiments of the transmitter may utilize an architecture comprised of a baseband modulator, a serial to parallel converter, a bank of multiplicity NT orthonormal transforms unit, a bank of multiplicity NT inverse Fourier transforms unit, a dummy symbols generator, and a minimum PAPR evaluation unit for finding the optimum transform index n0. Various embodiments of the receiver may comprise of a transform index detection unit for the detection of the transform index imbedded in the OFDM signal.