Abstract: A method for transmitting a signal in a wireless communication system. The method comprises the steps of: grouping two subcarriers having different channel characteristics; identifying a number of all cases occurring when either equal symbols or different symbols, among symbols determined upon applying a first modulation scheme, are mapped to the two subcarriers; and mapping two subcarriers corresponding to each of the number of all cases to one symbol according to a second modulation scheme, and transmitting the signal, wherein a modulation order of the second modulation scheme is two times higher than a modulation order of the second modulation.

Abstract: This invention provides a reception synchronization control device that controls reception synchronization of demodulated signals to be established, the demodulated signals being obtained by demodulating a phase modulated signal transmitted by a phase modulation, wherein the reception synchronization control device includes a signal level detector that detects signal levels of sampled demodulated signals extracted by sampling analog demodulated signals; a constellation position specifier that specifies constellation positions of plural kinds of data contained in the sampled demodulated signals displayed on a polar coordinates display based on the detected signal levels; and a phase angle difference calculation processor that calculates a difference between a phase angle calculated based on the specified constellation positions and a reference phase angle, thereby controlling the phase angle so that the difference is within a predetermined range.

Abstract: A direct conversion receiver and a method for correcting phase imbalance including applying an input signal to an in-phase channel and a quadrature channel of the receiver. The input signal is processed by the receiver to obtain an in-phase zero intermediate frequency (IF) signal in the in-phase channel and a quadrature zero-IF signal in the quadrature channel. The in-phase zero-IF signal and the quadrature zero-IF signal are filtered to obtain a fixed band signal. A phase imbalance correction value is obtained for the fixed-band quadrature zero-IF signal as a function of the frequency of the fixed-band in-phase zero-IF signal and the fixed-band quadrature zero-IF signal. The in-phase zero-IF signal and the quadrature zero-IF signal are sampled and the phase imbalance correction value is applied using an interpolation to the sampled quadrature zero-IF signal or to the sampled in-phase zero-IF signal to correct the phase imbalance in the direct conversion receiver.

Abstract: A symbol demapping method and apparatus for efficient interference cancellation in a wireless communication system. Decision signal points are generated which include decision signal points based on a modulation scheme and a virtual signal point added to a zero point. A magnitude of a complex value of an input signal is compared with a threshold based on system setting. When the magnitude of the complex value is less than the threshold, the virtual signal point of the zero point is mapped and output as a target decision signal point. When the magnitude of the complex value is greater than or equal to the threshold, one of the decision signal points based on the modulation scheme is mapped and output according to the com0plex value.

Abstract: The method is for managing the operation of a wireless communication device including several different communication modules respectively adapted to operate according to several given communication protocols including a UWB module operating according to a UWB protocol based on an OFDM modulation scheme. The method includes controlling the UWB module for scanning a chosen frequency band, and managing a communication to be performed by the device on the basis of the scanning result.

Abstract: A multi-carrier spread spectrum device using cyclic shift orthogonal keying includes: a modulation unit for receiving a first part of data bits and transforming the first part of data bits to a modulation symbol di by modulation; a cyclic-shift unit for receiving a base code c(0) and a second part of data bits, and performing a cyclic-shift to the base code c(0) in accordance with the second part of data bits to generate a CSOK symbol c(mi); and a multiplier for multiplying the modulation symbol di by the CSOK symbol c(mi) to generate a spread spectrum signal ci.

Abstract: According to one embodiment, a method of encoding a plurality of orthogonal frequency division multiplexing (OFDM) signals is disclosed. The method includes: modulating the plurality of OFDM signals according to a modulation scheme, wherein the modulated OFDM signals are mapped to a first axis and a second axis perpendicular to the first axis, and correspond to a first constellation having a plurality of points symmetric with respect to the first axis and the second axis; and differentially encoding the plurality of OFDM signals according to a second constellation plurality of points defined by shifting a position of one of the first constellation plurality of points toward an origin located at an intersection of the first axis and the second axis.

Abstract: A method for implementation of error correction decoding of quadrature layered modulation QLM communications. A bound on communications capacity derived using ideal QLM is approximated with QLM communications links which support data rates independent of the Shannon bound. Trellis symbol and bit demodulation algorithms recover QLM data symbols and bit algorithms offer computational efficiency at a cost of decisioning errors. Correlated bit decisioning error correction decoding and re-encoding can be implemented in a bit demodulation algorithm. Trellis demodulation and trellis decoding algorithms support parallel implementations, and concatenated implementations wherein the error correction decoding is implemented after the QLM demodulation. Concatenated implementation supports turbo decoding, MAP decoding, convolutional decoding, and block decoding by using the decisioning metrics available from QLM demodulation in place of generating the decisioning metrics directly from the detected symbol measurements.

Abstract: A multiband OFDM_UWB transmitting and receiving apparatus is provided in Low-IF configuration to solve problems attributed to a direct-conversion transmitting and receiving apparatus. A Low-IF receiver performs sorting by rotating a sub-carrier after FFT to eliminate the need for frequency conversion using a second local signal and uses the same AD conversion clock as that for a direct conversion receiver. An FFT-free preamble can be detected by using a sequence resulting from previously multiplying an original preamble pattern and an IF frequency together.

Abstract: A trellis processing technique for estimating a transmitted signal from a received signal acquired through a channel achieves a reduced computational structure when implementing a DDFSE-like branch metrics calculation by pre-storing computed values, which can be re-used. The technique involves storing differences between a received symbol and different products, each of which is a product of a channel coefficient corresponding to a least time delay and a different possible transmitted symbol. A summation of products is calculated, each product being a product of a possible transmitted signal symbol and a channel coefficient other than the channel coefficient corresponding to the least time delay, the summation being specific to a branch-start state in a trellis. The summation is combined with different stored differences in a calculation of branch metrics leading to different branch-end states in the trellis.

Abstract: Methods and apparatus for use in a multi-band OFDM wideband transmission systems are disclosed. A frame of source data is mapped by a transmitter for transmission using a first mapping. The frame of source data is then mapped by the transmitter for retransmission using a second mapping to increase frequency diversity. A receiver may identify source data that experiences fading and communicate the tone/frequency on which the fading occurred to the transmitter so that the transmitter may map the source data that experienced fading during transmission to another tone/frequency for retransmission.

Abstract: The invention relates to a method and a circuit arrangement for deciding a symbol upon the reception of a signal including or coupled with a quadrature signal pair, wherein the decision is made by means of an analysis of the metric of at least one reception point to at least one nominal point in a complex coordinate space, and the metric is analyzed in the non-Cartesian or not exclusively Cartesian complex coordinate space. The decision is made after the analysis, and during the decision process, a second most probable nominal point and a reliability of the decision are determined.

Abstract: The present disclosure relates generally to a system and method for a multi-layer multi-hop wireless system. In one example, the method includes dividing information to be sent from a source node to a destination node via a relay node into at least first and second segments. A signal containing the first and second segments is generated for transmission from the source node, where the first and second segments are encoded differently within the signal. The signal containing the first and second segments is sent from the source node to the relay node and the destination node. Only the first segment is recovered from the signal by the destination node, while the first and second segments are recovered by the relay node. The second segment is sent by the relay node to the destination node, which combines the first and second segments to reconstruct the information.

Abstract: Communication systems are described that use geometrically shaped constellations that have increased capacity compared to conventional constellations operating within a similar SNR band. In several embodiments, the geometrically shaped is optimized based upon a capacity measure such as parallel decoding capacity or joint capacity. In many embodiments, a capacity optimized geometrically shaped constellation can be used to replace a conventional constellation as part of a firmware upgrade to transmitters and receivers within a communication system. In a number of embodiments, the geometrically shaped constellation is optimized for an Additive White Gaussian Noise channel or a fading channel. In numerous embodiments, the communication uses adaptive rate encoding and the location of points within the geometrically shaped constellation changes as the code rate changes.

Abstract: A device may be capable of communicating using at least two type types of modulation methods. The device may include a transceiver capable of acting as a master according to a master/slave relationship in which communication from a slave to a master occurs in response to communication from the master to the slave. The master transceiver may send transmissions discrete transmissions structured with a first portion and a payload portion. Information in the first portion may be modulated according to a first modulation method and indicate an impending change to a second modulation method, which is used for transmitting the payload portion. The discrete transmissions may be addressed for an intended destination of the payload portion.

Abstract: A demodulator and demodulation method includes a bit/symbol hard demodulator configured to obtain hard bit or symbol information from a received signal. At least one lookup table is configured to reference coefficients for computation of log-likelihood ratios (LLRs) from the hard bit or symbol information. A log-likelihood ratio calculation module is configured to compute bit-level LLRs from the coefficients and the received signal.

Abstract: A quadrature demodulation device effectively utilizes the result of quadrature detection in order to improve demodulation efficiency. The quadrature modulation device includes a quadrature detector DT which performs quadrature detection on a reception signal obtained by receiving a radio wave from a radio frequency identification tag, to generate an in-phase signal and a quadrature-phase signal, and a demodulation circuit DM which detects a preamble of a particular transition pattern in at least one of the in-phase signal and the quadrature-phase signal and which decodes the at least one of the in-phase signal and the quadrature-phase signal to obtain data succeeding the preamble, the demodulation circuit DM further performing error detection on a decoding result to check for errors.

Abstract: In one aspect, the present invention greatly simplifies soft modulation calculations, in part by exploiting certain properties of Gray-mapped QAM constellations used in modulating symbols of interest. In at least one embodiment, the simplified processing includes performing the soft modulation separately for the real and imaginary parts of each symbol of interest, by using the Gray mapping to decompose each of the real and imaginary parts into binary soft modulations for each bit, and then using a computationally-efficient table lookup to calculate the binary soft modulation. Here, the look-up table comprises pre-computed bit contributions to the complex soft symbol value to be formed for the symbol of interest.

Abstract: A multiple-input multiple-output (MIMO) wireless communication system includes a first calculator for calculating pairwise error rates (PERs) for each modulation scheme combination which comprise elements smaller than or equal to receive antennas in number; a second calculator for calculating symbol error rates (SERs) for the each modulation scheme combination using the PERs; a converter for converting the SERs to effective signal to noise ratios (SNRs); and a determiner for determining one among sets of effective SNR per stream acquired from the modulation scheme combinations, as a final effective SNR per stream.

Abstract: A new frame structure applicable to the IEEE 802.16 OFDMA wireless waveform is described, for the purposes of increasing base station capacity, increasing subscriber link rates and extending base station range. The frame structure provides the necessary constructs so that advance signal processing technologies such as Stacked Carrier Spread Spectrum and adaptive antenna technology may be used in combination with these constructs in order to realize these gains. These concepts are equally applicable in other advanced wireless waveforms based on OFDM or OFDMA such as LTE or UMB.

Abstract: Improved ways of communicating assignment signals using flash signaling are described, e.g., for wireless terminals with low SNR, that are more robust against large variation of channel gains due to e.g., frequency selective fading and fast fading in time. Coding and modulation methods and apparatus that have excellent properties against symbol erasures are described. The use of flash signaling provides an improved assignment channel having strong performance on the fading channel without compromising the performance on the AWGN channel. In one exemplary embodiment, the coding and modulation method can tolerate up to 5 erased symbols out of 8 transmitted symbols. One embodiment reduces or minimizes the sector interference on the flash assignment by improving or maximizing orthogonality between different sectors. In addition, one embodiment describes improved ways of swapping flash assignment tone-symbols in the presence other high priority signals, like sector pilots and sector null pilots.

Abstract: A system and method for accelerated performance of quadrature amplitude modulation (QAM) is provided. The system includes multiple general purpose registers and multiple execution units configured to decode a set of QAM tones in parallel or an individual QAM tone in response to a single instruction executable by the processor. Each of the plurality of execution units is configured to decode one of the set of QAM tones according to a constellation size associated with the one of the set of QAM tones. The QAM decoding method includes reading a constellation size value for each of a set of received input tones. For each tone in the set of input tones, an ideal point in a QAM constellation of the associated constellation size closest to the X and Y coordinates of the tone is determined. The data values of the ideal points are then stored in a destination register.

Abstract: In a communication system, Huffman coding techniques are used to obtain shaping gains for an improvement in data transmission rates. More particularly, a novel method of Huffman shaping is described that achieves a shaping gain of greater than 1 dB. The shaping gain results in a higher data rate transmission in a communication system where transmitted power is constrained.

Abstract: To narrow the dynamic range of multicarrier signals and prevent both the increment of cost and the degradation of power efficiency. A modulating part (101) modulates transport data. An S/P converting part (102) performs an S/P conversion of a modulated symbol and outputs the modulated symbols, the number of which is the same as the number of all subcarriers, to an IFFT part (103) in parallel. The IFFT part (103) assigns the modulated symbols to the subcarriers, the frequencies of which are orthogonal to each other, to perform an inverse fast Fourier transform. A P/S converting part (104) performs a P/S conversion of the signals of time domain. When the instantaneous amplitude level of an OFDM signal is lower than a predetermined threshold value, a pit clip part (105) replaces this amplitude level by the predetermined threshold value.

Abstract: Distributed CMTS device for a HFC CATV network serving multiple neighborhoods by multiple individual cables, in which the QAM modulators that provide data for the individual cables are divided between QAM modulators located at the cable plant, and remote QAM modulators ideally located at the fiber nodes. A basic set of CATV QAM data waveforms may be transmitted to the nodes using a first fiber, and a second set of IP/on-demand data may be transmitted to the nodes using an alternate fiber or alternate fiber frequency, and optionally other protocols such as Ethernet protocols. The nodes will extract the data specific to each neighborhood and inject this data into unused QAM channels, thus achieving improved data transmission rates through finer granularity. A computerized “virtual shelf” control system for this system is also disclosed. The system has high backward compatibility, and can be configured to mimic a conventional cable plant CMTS.

Abstract: Method and system for allowing abandoning pilot signals use and for increasing the immunity to Doppler Effect influence in OFDMA based wireless mobile communication systems and as a result, make them more efficient. This is carried out by transmitting N orthogonal I and Q values of symbols, N times on N frequencies, where N is a power of two. In order to be able to select the desired signal from a mixture of N signals, signs of symbol of each signal vary according to one of N-order Walsh functions.

Abstract: A method and system of wireless communication is provided which involves inputting information bits, wherein certain bits have higher importance level than other bits, and applying unequal protection to the bits at different importance levels. As such, important bits are provided with more protection for transmission and error recovery. Applying unequal protection involves using skewed constellations such that more important bits are provided with more error recovery protection.

Abstract: Methods and apparatus for determining the starting points of redundancy version transmissions in a circular rate matching operation. At least one block of information bits to be transmitted are encoded to generate a plurality of coded bits, which are then segmented into a plurality of sub-blocks of coded bits. Each of the sub-blocks of coded bits is interleaved by using a certain interleaver. The interleaved coded bits of the plurality of sub-blocks are collected and filled into a circular buffer having a plurality of redundancy versions in the circular buffer, with each redundancy version corresponding to a starting bit index in the circular buffer. For each transmission, a subset of bits are selected from the circular buffer by selecting a redundancy version from among the plurality of redundancy version. The selected subset of bits are modulated by using a certain modulation scheme, and are transmitted via at least one antenna.

Abstract: Methods and apparatus are provided for prescribed response precoding schemes for signal transmission in channels with intersymbol interference. An embodiment includes generating a prescribed feedback filter polynomial as the quotient of a feedback filter polynomial and a target polynomial to form a feedback filter in a precoder, where the target polynomial is a divisor of the feedback filter polynomial.

Abstract: Various techniques involving polar modulation are disclosed. For instance, an apparatus may include a storage medium and a calibration module. The storage medium stores multiple adjustment settings. Each of these adjustment settings corresponds to an operating condition. The calibration module selects one of the stored adjustment settings that corresponds to a current operating condition. With the selected adjustment setting, the calibration module reduces a polar modulation timing misalignment. The current operating condition may include one or more operational parameter values. Examples of such parameter values include output power level, signal frequency, and/or temperature.

Abstract: A method of transmitting data in a multi-carrier communication system is disclosed. More specifically, the method includes mapping at least one data symbol to at least one subcarrier of a first frequency domain and at least one data symbol to at least one subcarrier of a second frequency domain, wherein the first frequency domain and the second frequency domain are mutually exclusive and the at least one data symbol mapped to the at least one subcarrier of the second frequency domain is multiplied by a spreading code, transforming the at least one data symbol mapped to the first frequency domain and the at least one data symbol mapped to the second frequency domain by an inverse discrete Fourier transform (IDFT) module, and transmitting the transformed data symbols to a receiving end.

Abstract: Communication systems having transmitter, includes a coder configured to receive user bits and output encoded bits at an expanded output encoded bit rate, a mapper configured to map encoded bits to symbols in a symbol constellation, a modulator configured to generate a signal for transmission via the communication channel using symbols generated by the mapper. In addition, the receiver includes a demodulator configured to demodulate the received signal via the communication channel, a demapper configured to estimate likelihoods from the demodulated signal, a decoder that is configured to estimate decoded bits from the likelihoods generated by the demapper. Furthermore, the symbol constellation is a capacity optimized geometrically spaced symbol constellation that provides a given capacity at a reduced signal-to-noise ratio compared to a signal constellation that maximizes dmin.

Abstract: Disclosed is a method and communication device for suppressing interference. The method comprises performing, with a turbo decoder (314), at least one turbo decoding attempt (1106) on a received signal (1104). The turbo decoding attempt generates at least one whole word code bit therefrom (1108). The whole word code bit (1108) corresponds to a group of bits comprising a transmitted symbol. The method determines if the whole word code bit (1108) has a confidence level exceeding a given threshold (1110). If the whole word code bit (1108) does have a confidence level exceeding the given threshold, the whole code word bit is selected for use in data symbol recovery (1114).

Abstract: Non-symmetric OFDM system may employ different spectrum bandwidths, different FFT sizes, different cyclic prefixes, different symbol duration and different modulation schemes in two ends of the communication. The transmission spectrum can be one contiguous piece or multiple disjoint pieces by modulating zeros to those subcarriers nearby the spectrum boundaries. Transmitter and receiver maybe designed separately and integrated together via a control module to form a transceiver.

Abstract: This method for carrying out the flexible demodulation of data modulated following an amplitude modulation in quadrature is used in a communications system employing a code division multiple access technique (CDMA) and an optical frequency division multiplexing (OFDM) using non-binary spread codes. The invention includes steps for determining a simplified expression specific to the logarithm of the likelihood ratio.

Abstract: A method of automated acquisition of a QAM signal is provided. The method employs a State machine progressing from an initial State to a final State. The State machine comprises: a symbol timing recovery loop; a carrier loop; a coarse frequency loop; and an equalizer. The method comprises: (A) Performing an automatic gain control (AGC) operation on an incoming QAM signal; (B) Performing a symbol timing recovery of an input QAM signal by adjusting a sampling clock of the symbol timing recovery loop; (C) Performing a Blind Equalization of the QAM signal without carrier lock; (D) Performing a carrier recovery of the QAM signal; and (E) Performing a decision directed equalization (DDE) of the QAM signal by updating a set of coefficients of the equalizer by using a decision based algorithm.

Abstract: Digital Visual Interface (DVI), or High Definition Multi-media Interface (HDMI), data is received from a source and sent to a transmitter chip that includes a transition minimized differential signaling (TMDS) receiver that outputs a 3-data and 1-clock physical signaling stream representing the DVI or HDMI data. This stream is rendered into I and Q data by an ASIC or FPGA and sent to a wireless transmitter for modulation, upconverting, and transmission to, e.g., a nearby display device without ever rendering the data into baseband video on the transmitter chip. The display device has a receiver chip that is essentially the inverse of the transmitter chip.

Abstract: A method of transmitting data including controlling generation of bit sequences to adjust an occupation rate occupied with predetermined bits included in a first data block, which is obtained by encoding first data, to be closer to an occupation rate occupied with predetermined bits included in a second data block, which is obtained by encoding second data. With regard to first bit positions of the predetermined bits, the first bit positions being distinguished from second bit positions based on an error tolerance resulting from a correspondence to a signal point on a phase plane. Wherein a sum of a number of the predetermined bits included in the first data block and the predetermined bits included in the second data block is less than a total number of the first bit positions. Also including performing multi-level modulation for transmission based on the generated bit sequences.

Abstract: A transmission system includes an emitter (100) that includes an iFFT block (101) coupled to a set of memories (102-105) feeding a weighted summation device (106). Switches (113, 114, 115) are introduced at the intput of the memories, in order to load the set of samples provided by the iFFT block when the first symbol is fed to the input of the emitter. This system may also include a receiver (200) that includes a set of memories (202-205) feeding a weighted summation device (206) coupled to a FFT block (201). Switches (213, 214, 215) are introduced at the input of the memories in order to load the set of samples received, corresponding to the first transmitted symbol. A method of transmission with preloading of the memories that is extended to OQAM modulation and MIMO systems is also described.

Abstract: A method and apparatus are provided for coding an OFDM/OQAM-type multi-carrier signal formed by a temporal succession of symbols comprising a set of data elements. Each of the data elements modulates a carrier frequency of the signal. Each of the data elements is formed by adding two real values in quadrature, which each correspond to a binary word of a source signal, which is modulated using a pre-determined modulation constellation, such as to transmit information over a real channel and an imaginary channel of the OFDM/OQAM symbols.

Abstract: An RF signal source having a camera that provides a camera output, an encoder that encodes the camera output in a compressed digital format, and a modulator that digitally encodes and modulates the compressed camera output and that provides the digitally encoded, modulated, and compressed camera output as an RF output of the RF signal source. The camera, the encoder, and the modulator may be contained in an enclosure. Additionally or alternatively, the encoder, the modulator, and at least part of the camera may be formed on a semiconductor substrate.

Abstract: Transmit diversity system in which constellation rearrangement is used. Both diversity signals contain the same data and both are 16-QAM, but the location of the data bits within the constellation is different. This averages the effect of the different levels of reliability of the different constellation points. A method for modifying a quadruple of data bits in a data transmission system using Quadrature. Amplitude Modulation with 16 different modulation states, 16-QAM, using an Antipodal Inverted Constellation AICO) mapping, swapping bits selecting contiguous symbol regions with bits selecting non-contiguous symbol regions. Depending on the particular pre-defined mapping and on the particular permutation of bits, inversion of selected bits may be performed in addition. The quadruples thus obtained are mapped to modulation symbols according to a pre-defined AICO mapping.

Abstract: An apparatus and method for supporting distortionless vector perturbation in a Multi-Input Multi-Output (MIMO) system are provided. The apparatus includes a transmitter for supporting distortionless vector perturbation in a MIMO system. The transmitter includes a label inserter for generating a label and for inserting the label into a user information bit, a scrambler for scrambling the user information bit inserted with the label and for generating N independent candidate sequences, a modulator for modulating the N independent candidate sequences according to a modulation scheme and a vector perturbation unit for adding a limited offset vector so that the modulated symbols are mapped to a constellation point in a feasible region. The apparatus and method provide vector perturbation with improved performance and reduced computational complexity.

Abstract: A communications receiver may include an adaptive filter unit for removing coherent interference components from a received signal. In the absence of a signal of interest, the filter may adapt dynamically to remove current interference components. When a signal of interest is detected, the filter may be controlled to stop (or at least reduce) its adaptation, to prevent removal of the signal of interest. The received signal may be down-converted to a complex baseband by conditioning circuitry. A detector may detect the signal of interest, and control the filter. Autocorrelation may be used to estimate a characteristic of the signal of interest in the complex baseband. The detector may include hysteresis to react quickly to the start of signal of interest, and more slowly to an end of the signal of interest. The signal of interest may be a frequency shift keyed (FSK) signal. A demodulator may demodulate FSK components based on the autocorrelation result.

Abstract: Apparatus and methods for transparently using otherwise wasted bandwidth associated with variable-rate program streams to deliver additional content. In one embodiment, the network comprises a broadcast switched architecture (BSA), and the program streams are loaded up to a target rate using “null” packets and then delivered over the network infrastructure to a plurality of hub sites. The streams are then unloaded to reproduce the original variable streams, and the bandwidth vacated by removal of the null packets used as the transport mechanism for additional (e.g., non time-sensitive) content to be delivered to the subscribers. The process can also be substantially automated and anticipatory (through, e.g., transmission of null bit insertion data downstream). The invention can also advantageously be implemented with minimal modifications to existing infrastructure, and supports business and operational supervisory processes.

Abstract: The present invention relates to a method for processing digital signals and to a transmission/reception system implementing said method; the present invention is based on the use of LDPC codes, in particular the LDPC code of the DVB-S2 standard, in combination with a QAM modulation, in particular the 1024QAM and 4096QAM modulations; in transmission, a bit permutation (Demux) is carried out prior to the QAM constellation mapping function; in reception, the bit permutation is carried out after the QAM constellation demapping function.

Abstract: Techniques for transmitting data from a transmitter unit to a receiver unit in a multiple-input multiple-output (MIMO) communication system. In one method, at the receiver unit, a number of signals are received via a number of receive antennas, with the received signal from each receive antenna comprising a combination of one or more signals transmitted from the transmitter unit. The received signals are processed to derive channel state information (CSI) indicative of characteristics of a number of transmission channels used for data transmission. The CSI is transmitted back to the transmitter unit. At the transmitter unit, the CSI from the receiver unit is received and data for transmission to the receiver unit is processed based on the received CSI.

Abstract: An I/Q calibration system for a quadrature amplitude modulation (QAM) mode transceiver includes a signal generator that generates reference in-phase (I) and quadrature (Q) signals. An I/Q mismatch compensation module generates compensated I and Q signals based on the reference I and Q signals and amplitude and phase correction signals. An I/Q mismatch calibration module generates the amplitude and phase correction signals. A phase stepper module varies a phase of the reference I and Q signals based on the amplitude and phase correction signals.

Abstract: A multi-class multimedia broadcast/multicast service (MBMS) system includes a transmitter and at least one receiver. The transmitter transmits N primary signals by N primary channels and an auxiliary signal by an auxiliary channel, wherein a resolution of the auxiliary signal is identical to a resolution of the primary signal with the highest resolution and the constellation mappings of the auxiliary signal and the primary signal with the highest resolution on the corresponding modulation constellations can be coupled. The receiver couples the primary signal with the corresponding auxiliary/virtual auxiliary signal to obtain a lower-resolution virtual auxiliary signal, which can also be coupled with the primary signal having the same resolution. Therefore, receiving quality of each resolution is improved by combining the primary signal and the corresponding auxiliary/virtual auxiliary signal.

Abstract: A system, a method and an apparatus are disclosed herein for receiver terminal driven joint encoder and decoder mode adaptation for SU-MIMO transmission. In one embodiment, the system comprises a transmitter that is able to be directed to transmit wireless signals over a multiple-input, multiple output (MIMO) system using any of a plurality of encoding modes; and a user terminal having a receiver comprising a decoding module which has a plurality of decoding modes, each of which can be used to decode communications from the transmitter received over a multiple-input, multiple output (MIMO) channel, wherein at least one encoding mode is operable with multiple of the decoding modes.