Abstract: Techniques to calibrate downlink and uplink channels to account for differences in the frequency responses of transmit and receive chains are described. In one embodiment, pilots are transmitted on downlink and uplink channels and used to derive estimates of the downlink and uplink channel responses, respectively. Sets of correction factors are then determined based on estimates of downlink and uplink channel responses. A calibrated downlink channel is formed using a first set of correction factors for the downlink channel, and a calibrated uplink channel is formed using a second set of correction factors for the uplink channel. The first and second sets of correction factors may be determined using a matrix-ratio computation or a minimum mean square error computation. The calibration may be performed in real-time based on over-the-air transmission. Other aspects, embodiments, and features are also claimed and described.

Abstract: Disclosed are an apparatus and method for transceiving a signal using a frame structure appropriate for a high-speed moving body. The method for transceiving a signal using a predetermined frame structure according to the present invention comprises a step of transceiving a signal via a frame having the predetermined frame structure, wherein one frame is constituted by eight subframes, and said frame consists of a type-1 subframe consisting of six orthogonal frequency division multiple access (OFDMA) symbols and a type-2 subframe consisting of seven OFDMA symbols, and said frame has a cyclic prefix length which is either 0, 1/32 of the useful symbol length, 1/64 of the useful symbol length, or 1/128 of the useful symbol length.

Abstract: Methods and apparatuses to adaptively select radio frequency channels with which to connect a mobile wireless device to a wireless network are described. In response to a trigger event, the mobile wireless device selects a radio frequency channel from a list of radio frequency channels that use a first radio access technology and transmits a series of connection requests on the selected radio frequency channel. When no acknowledgement is received, the mobile wireless device excludes the selected radio frequency channel from the list of radio frequency channels and repeats the selecting, transmitting and excluding steps up to a maximum number of repetitions before attempting to connect to the wireless network using a second radio access technology.

Abstract: A method for wireless communication supporting uplink and downlink multi carriers Includes performing initial access through one of at least two downlink component carriers among multiple downlink component carriers including the at least two downlink component carriers through which the user equipment is allowed to perform the initial access; and transmitting via an uplink component carrier allocated to the user equipment by using a carrier identifier, wherein the carrier identifier is applied to the uplink component carrier and is obtained from the downlink component carrier through which the initial access is performed, and wherein the system pre-defines one-to-one correspondence between multiple downlink component carriers and multiple uplink component carriers, and wherein the downlink component carrier through which the initial access is performed and the uplink component carriers allocated to the user equipment do not match the one-to-one correspondence pre-defined by the system.

Abstract: A radio terminal (1100A) comprises a communication unit (1120), a measurement unit (1140A), a measurement unit (1140B), and a control unit (1160A). The communication unit (1120) selects one of the CDMA (Code Division Multiple Access) scheme and the OFDM (Orthogonal Frequency Division Multiplexing) scheme as a communication scheme to be used in a cell formed by a radio base station and performs radio communication. The measurement unit (1140A) measures the receiving quality relating to the time difference between the preceding wave of a received signal and the delayed wave thereof in the OFDM scheme. The measurement unit (1140B) measures the receiving quality of a received signal in the CDMA scheme.

Abstract: A method for a user equipment (UE) to receive a PDCCH (physical downlink control channel) transmitted from a base station via a specific resource region includes receiving a PBCH (physical broadcast channel) including first system information and PHICH (physical hybrid ARQ indicator channel) related information from the base station and receiving the PDCCH transmitted from the base station via the specific resource region for downlink control information.

Abstract: A receiving apparatus includes a symbol timing detection unit, a Fourier transform unit, a first symbol timing correction unit, and an interpolation synthesis unit. The symbol timing detection unit is configured to detect a Fourier transform start position from a received transmitting signal of a symbol unit, the Fourier transform unit is configured to perform a Fourier transform using the detected Fourier transform start position. The first symbol timing correction unit is configured to calculate and correct an amount of change between the Fourier transform start position of a reference symbol and the detected Fourier transform start position, and the interpolation synthesis unit is configured to perform an interpolation synthesis of a plurality of delay profiles corresponding to a plurality of symbols including the reference symbol and a symbol in which the amount of change is corrected.

Abstract: Methods and apparatus for processing a downlink (DL) subframe of an orthogonal frequency-division multiplexing (OFDM) or an orthogonal frequency division multiple access (OFDMA) frame are provided. By arranging the DL-MAP information elements (IEs) in a DL-MAP of the DL subframe to correspond chronologically to the arrangement of their associated data bursts in the OFDM or OFDMA frame at a base station (BS), a user terminal receiving that frame may be able to start decoding the data bursts in the DL subframe without having to wait until all of the DL-MAP IEs have been parsed and decoded. In this manner, the user terminal may decode the data bursts while simultaneously parsing a remaining portion of the DL-MAP, and the time for processing the entire frame may be reduced, thereby increasing the processing speed.

Abstract: A wireless transmit/receive unit (WTRU) that may receive an asymmetrically clipped optical orthogonal frequency-division multiplexing (ACO-OFDM) signal is disclosed. The ACO-OFDM signal may include an ACO-OFDM symbol and the ACO-OFDM signal may be generated with or without a pilot or training data. Where the ACO-OFDM signal may not include a pilot or training data, the WTRU may determine a correlation minimum between a first part of N samples of the ACO-OFDM symbol and a second part of N samples of the ACO-OFDM symbol. The correlation minimum may indicate an estimated boundary of the ACO-OFDM symbol which may provide the WTRU with timing synchronization information. Where the ACO-OFDM signal may include one or more ACO-OFDM pilot symbols on one or more pilot subcarriers, the WTRU may interpret an amount of training data included in the one or more ACO-OFDM pilot symbols that may provide information for channel estimation.

Abstract: An ASN coding unit of a mobile station apparatus generates mobile station component carrier capability information including information that defines a component carrier that supported by communication with a base station apparatus. A transceiver device transmits, to the base station apparatus, mobile station component carrier capability information. A control unit controls a communication with a base station apparatus, the control being made by using a component carrier allocated by a base station apparatus, the allocation being made based on mobile station component carrier capability information.

Abstract: A method for detecting a channel in a mixed-mode communications system is presented. The channel contains a primary synchronization pattern in a predetermined location within the channel. The primary synchronization pattern is compared against different predetermined channel synchronization patterns to detect a channel. Upon detection of the channel, a look-back channel detector confirms the existence of the channel by using the location of the primary synchronization pattern. Detection and confirmation of the channel may be employed simultaneously to each channel of a multiple-channel direct mode of operation signal. Audio holes may be eliminated in a 2:1 TDMA direct mode operation where both time slots contain signals from two different originating communication devices and the signals have different priority.

Abstract: A method and an apparatus for Inverse Fast Fourier Transform (IFFT) in a communication system are provided. The method includes determining an IFFT size based on a number of input information symbols, and performing an IFFT operation based on the determined IFFT size.

Abstract: Methods and apparatus related to broadcasting data and interference management in a peer to peer wireless communications network are described. Scheduling of traffic air link resources is performed on a slot by slot basis in a decentralized manner. Wireless devices intending to broadcast traffic signals transmit broadcast request signals, sometimes alternatively referred to as broadcast indicator signals. A priority level is associated with each of the broadcast request signals. A receiver device intending to receive broadcast signals detects the broadcast request signals and makes an interference determination as to whether the higher priority broadcast traffic signal can be successfully recovered in the presence of lower priority broadcast traffic signals.

Abstract: A transmission of information within a wireless cellular network may include a first and second group of samples. A first group of samples is created comprising at least a first and a last subgroup, wherein the last subgroup is same as the first subgroup. A second group of samples created. A transformed set of samples produced by jointly transforming the created first and second group with a discrete Fourier transform (DFT). The transformed set of samples is expanded to produce an expanded set, and the expanded set is transformed with an inverse discrete Fourier transform (IDFT) to produce an OFDM symbol with a fractional payload. The first group of samples is a reference signal (RS), which is known to the receiver before the transmission occurs, while the second group of samples is information data.

Abstract: The present invention relates to receiving access signals from a plurality of terminals over a radio channel and in particular to determining a detection threshold level on the radio channel. A detection threshold level should balance the risk of missed detections to the risk of false detections. A problem in finding an equilibrium threshold is the radio environment, with noise and interference, change and then also the radio false detections or missed detections change. According to the present invention some access signals can be identified as being not assigned and therefore not being in use, and any detection of a non-used signal is identified as a false detection. By monitoring the ratio of false detections vs. correct detections the threshold level for detection is tuned into an equilibrium level, and that is adapted to the changing radio environments.

Abstract: Techniques for transmitting configurable pilots in a wireless communication system are described. The placement of pilots is determined based on an assignment of resources for transmission. Different placements of pilots are used for different assignments of resources. The assignment may be for one or more frames and/or one or more H-ARQ interlaces. The placement of pilot(s) in each frame or H-ARQ interlace may be determined based on the placement of pilot(s) in prior frame(s) or H-ARQ interlace(s). Pilots are sent at time and frequency locations determined by the placement of the pilots. Each pilot may be sent on one or more subcarriers in one or more symbol periods. The pilots may be TDM pilots and/or some other type of pilot. The pilots may be sent using IFDMA, LFDMA, EFDMA, OFDMA, or some other multiplexing scheme.

Abstract: A method and apparatus for defining transmission parameters of user equipment reference signals. The method includes estimating channel delay spreads of a plurality of user equipments scheduled for transmission at a particular transmission time period or sub-frame in an uplink for communication with a NodeB, and allocating transmission parameters to each scheduled user equipment of the plurality of user equipments in accordance to the delay spreads of the plurality of user equipments scheduled for transmission in the particular time period or sub-frame, wherein the parameters comprises a cyclic shift allocated to each m-th user equipment equal to the sum of a delay spread and a timing uncertainty of each of the previous m-1 user equipments.

Abstract: A method and apparatus for coordinating the resource assignment of a plurality of channel segments in a wireless communication system are disclosed. The method includes the steps of determining a number of resources available, determining a number of channel segments to include in a frame, determining a number of resource zones to be used for resource assignment of the plurality of channel segments, assigning each channel segment of the number of channel segments to a resource zone of the number of resource zones, and selecting a resource from the number of resources for transmitting said each channel segment in said resource zone.

Abstract: A wireless communication method of a base station that transmits a modulation signal based on an orthogonal frequency division multiplexing scheme to a plurality of terminals. The method includes determining, for each terminal of the plurality of terminals, which subcarrier group or how many symbols along a time axis are to be allocated in a transmission frame, the transmission frame including a first period in which first transmission symbols are arranged and a second period in which second transmission symbols which are different from the first transmission symbols are arranged. The method also includes forming the transmission frame according to a determined allocation, wherein a plurality of symbols on a frequency axis for transmitting N bits (N is a natural number) are arranged within a part of the first period, by using a modulation scheme whereby N bits can be transmitted using one symbol. The method further includes transmitting the modulation signal using the transmission frame.

Abstract: A data transmission method using spatial multiplexing is disclosed. The data transmission method using spatial multiplexing includes modulating at least one codeword to generate at least one modulation symbol, mapping the at least one modulation symbol to a layer whose number is determined according to its rank to generate a layer-mapped symbol stream, performing discrete Fourier transform (DFT) on the layer-mapped symbol stream to generate a frequency domain symbol stream, performing precoding on the frequency domain symbol stream, mapping the precoded frequency domain symbol stream to subcarriers, and then performing inverse fast Fourier transform (IFFT) on the precoded frequency domain symbol stream-mapped subcarriers to generate SC-FDMA symbols; and transmitting the SC-FDMA symbols by using a plurality of transmission antennas. Spatial multiplexing having a low PAPR can be possibly performed in an SC-FDMA system.

Abstract: A processing unit sets the time interval before packet signals are broadcast, using a carrier sense multiple access (CSMA) scheme. A modem unit and an RF unit broadcasts the packet signals at the time intervals set by the processing unit. The RF unit and the modem unit receive a control signal broadcast from an access control apparatus at a predetermined frequency. The processing unit sets the time interval, during which the control signal is receivable, to a time length shorter than the time interval for the remaining cases.

Abstract: A method is provided for reducing the peak power level in a combination of orthogonal frequency division multiplexed (OFDM) tones. The method is particularly effective when the information to be communicated is digital data consisting of long patterns of “1”s or “0”s. The digital data of the message is combined with a scrambling vector before the data is modulated. The randomization of data patterns, in turn, leads to a more random combination of OFDM tone amplitude being transmitted. The message is recovered at the receiver by removing the scrambling vector. An OFDM communication system using the above-described method is also provided.

Abstract: A method for generating a downlink signal in a downlink MIMO (Multiple Input Multiple Output) comprises the steps of: mapping at least one transport block to at least one codeword; mapping at least one layer to each codeword; classifying at least one layer mapped to each codeword into a certain number of layer groups and performing layer permutation by the layer groups; and generating an OFDM (Orthogonal Frequency-Division Multiplexing) symbol using a signal which is permutated by the layer groups. A CRC (Cyclic Redundancy Check) is attached by the layer groups.

Abstract: The present invention relates to a method for generating a plurality of demodulation reference signal (DM-RS) sequences, a communication terminal device using same, and a base station using same, which generate N DM-RS sequences by adding additional parameters having N (?2) values or N numbers of cases after designing a basic DM-RS sequence for one or more layers. Thereby, each terminal can easily obtain layer information assigned thereto except for basic precoder information from DM-RS and can further predict interference and the like among terminals by obtaining layer information of other terminals.

Abstract: A pilot frequency transmitting method comprises: in a downlink frame, a base station transmitting a MIMO midamble on the jth symbol of the ith downlink subframe; wherein i is a natural number which is less than or equal to the maximum number of downlink subframes included in the downlink frame, and j is a natural number which is less than or equal to the maximum number of symbols included in the downlink subframe. Accordingly, the present invention also provides a pilot frequency transmitting method and a base station for transmitting a MIMO midamble. The present invention can obtain a better effect for channel measurement by selecting an appropriate transmitting opportunity and/or manner of the MIMO midamble.

Abstract: A method and an apparatus for transmitting data in a multi-antenna system are provided. The method includes: selecting a plurality of modulation symbol blocks including at least one modulation symbol from total modulation symbols of a codeword, repeating the plurality of modulation symbol blocks in a time domain, combining the repeated plurality of modulation symbol blocks, and performing discrete Fourier transform (DFT) on the combined plurality of modulation symbol blocks.

Abstract: The present invention provides a method involving a configurable random access channel structure. One embodiment of the method includes generating a random access channel burst that includes a cyclic prefix and a selected number of repetitions of a preamble. The number of repetitions is selected based on at least one of a cell radius and a radio transmission frequency. This embodiment of the method also includes transmitting the random access channel burst over an air interface.

Abstract: Filtering and modulating a first rate data signal into a Quadrature Amplitude Modulated (QAM) Code Division Multiple Access (CDMA) and a second rate data signal into a Time Division Multiple Access (TDMA) modulated signal and selecting between the transmission of the CDMA and TDMA modulated signals. A method for nonlinearly and linearly amplifying TDMA and CDMA signals. A diversity receiver and demodulator method for receiving and demodulating transmitted modulated signals. Processing, transmit baseband filtering and modulating signals for providing cross-correlated in-phase and quadrature-phase Gaussian filtered Gaussian Minimum Shift Keying (GMSK) and other cross-correlated modulated signals and spread spectrum Quadrature Phase Shift Keying (QPSK) modulated signals.

Abstract: An ASN encoder of a mobile station apparatus generates transmission and reception capability information including information relating to one or a plurality of component carriers to be used for communication with a base station apparatus. A transmission and reception apparatus transmits the transmission and reception capability information to the base station apparatus. A controller controls the communication with the base station apparatus, using the one or the plurality of component carriers assigned by the base station apparatus based on the transmission and reception capability information.

Abstract: The present application provides methods, devices and transmitters that mitigate increases in peak to average power ratio (PAPR) from transmission diversity in a single carrier frequency division multiple access (SC-FDMA) modulated uplink A PAPR preserving precode matrix hopping method that utilizes cyclic shift delays is provided, as well as a sub-band based transmit diversity scheme. The present application also provides methods, devices and transmitters that relax the scheduling restrictions associated with uplink scheduling in the LTE standard.

Abstract: A method for transmitting channel status information (CSI) of downlink multi-carrier transmission includes generating the CSI including at least one of a rank indicator (RI), a first precoding matrix index (PMI), a second PMI and a channel quality indicator (CQI) for one or more downlink carriers, the CQI being calculated based on precoding information determined by a combination of the first and second PMIs, determining, when two or more CSIs collide with one another in one uplink subframe of one uplink carrier, a CSI to be transmitted on the basis of priority, and transmitting the determined CSI over a uplink channel. If a CSI including an RI or a wideband first PMI collides with a CSI including a wideband CQI or a subband CQI, the CSI including a wideband CQI or a subband CQI has low priority and is dropped.

Abstract: An advanced technology frame structure is described herein. The advanced technology frame structure can enhance a first technology frame structure in dimensions of time, frequency, or a combination of time and frequency. A second technology frame structure time division multiplexes second technology subframes with the first technology downlink and uplink subframes. The first technology downlink subframe can be divided into a first technology downlink subframe and one or more second technology downlink subframes. Similarly, the first technology uplink subframe can be divided into a first uplink subframe and one or more second technology uplink subframes. These principles can be expanded upon and can be applied in many communication systems.

Abstract: Techniques to transmit data with cyclic delay diversity and pilot staggering are described. For cyclic delay diversity, OFDM symbols having different cyclic delay durations are generated. The cyclic delay durations for the OFDM symbols may be selected to be time varying with respect to the cyclic delay durations for OFDM symbols transmitted by a neighboring base station. An FDM pilot is generated and multiplexed on multiple sets of subbands in different symbol periods. Waveforms for a second radio technology (e.g., W-CDMA) may be generated for data to be transmitted with this radio technology. The OFDM symbols are multiplexed onto time slots used for OFDM, and the waveforms for the second radio technology are multiplexed onto time slots used for this radio technology. One or multiple modulated signals may be generated based on the multiplexed OFDM symbols and waveforms. Each modulated signal is transmitted from a respective antenna.

Abstract: The present invention relates to a method and apparatus for efficiently using a resource in a relay system. In detail, the present invention relates to a method for controlling an uplink signal transmission of user equipment in a wireless communication system, and to an apparatus for same. The method comprises the following steps: checking a cell-specific first SRS transmission subframe set; checking a relay-specific second SRS transmission subframe set; and allocating a resource for the uplink signal transmission. The uplink signal is transmitted to a relay via a backhaul subframe in the event the backhaul subframe falls within the first SRS transmission subframe set but does not fall within the second SRS transmission subframe set. The uplink signal transmission is dropped from the backhaul subframe in the event the backhaul subframe falls within the second SRS transmission subframe set.

Abstract: A wireless communication system is disclosed including a MIMO wireless communication apparatus that can communicate through multiple antennas and a non-MIMO wireless communication apparatus that can communicate through a single antenna or multiple antennas. The MIMO wireless communication apparatus includes a communication unit configured to transmit and receive control information divided into a second control information containing information related to the demodulation and decoding of traffic channel and a first control information containing information related to the MIMO separation of the second control information.

Abstract: A system comprises transceiver logic that receives signals on each of an array of frequencies. The transceiver logic is adapted to communicate using a first communication protocol. Processing logic couples to the transceiver logic. The processing logic identifies from among the array of frequencies a subset of shared frequencies that carry data transmitted using a second communication protocol. The processing logic adjusts frequency selection parameters in accordance with the identification. The processing logic uses the adjusted frequency selection parameters to select a target frequency from the array of frequencies to carry data.

Abstract: Techniques for transmitting data using single-carrier frequency division multiple access (SC-FDMA) multiplexing schemes are described. In one aspect, data is sent on sets of adjacent subbands that are offset from one another to achieve frequency diversity. A terminal may be assigned a set of N adjacent subbands that is offset by less than N (e.g., N/2) subbands from another set of N adjacent subbands assigned to another terminal and would then observe interference on only subbands that overlap. In another aspect, a multi-carrier transmission symbol is generated with multi-carrier SC-FDMA. Multiple waveforms carrying modulation symbols in the time domain on multiple sets of subbands are generated. The multiple waveforms are pre-processed (e.g., cyclically delayed by different amounts) to obtain pre-processed waveforms, which are combined (e.g., added) to obtain a composite waveform. A cyclic prefix is appended to the composite waveform to generate the multi-carrier transmission symbol.

Abstract: The invention provides a method of handover from an active network to a selected one of a plurality of potential other networks. In addition to the overall solution, the solution proposed has several individual aspects. All subsidiary aspects are related to the common problem mentioned above and sharing the underlying common solution concept of implementing a system in which selective handover is possible and in which a list of available other networks provided by an active network can be handled and selection made by a terminal, so that neighbor cell information can be transmitted based on expressed terminal preferences.

Abstract: A system, apparatus, method and article to manage diversity for a wireless multicarrier communication system are described. An apparatus may include a diversity agent to couple to a transmitter, the diversity agent to convert a determined number of input bits into symbols, interleave the symbols across multiple spatial streams, and map the symbols to tones for each spatial stream. Other embodiments are described and claimed.

Abstract: A wireless communication system is disclosed including a MIMO wireless communication apparatus that can communicate through multiple antennas and a non-MIMO wireless communication apparatus that can communicate through a single antenna or multiple antennas. The MIMO wireless communication apparatus includes a communication unit configured to transmit and receive control information divided into a second control information containing information related to the demodulation and decoding of traffic channel and a first control information containing information related to the MIMO separation of the second control information.

Abstract: Apparatus and methods are disclosed for testing or qualifying a repeater/transmitter in a multicarrier system by utilizing modulation error ratio (MER). In particular, a disclosed method includes determining an estimated effective modulation error ratio of an output of the repeater/transmitter. The estimated effective modulation error ratio is compared with a predetermined threshold, and the repeater/transmitter is qualified when the estimated effective modulation error ratio is greater than the predetermined threshold. Using an estimated modulation error ratio for repeater/transmitters, which can have non-flat modulation error ratios over a total number of subcarriers, affords an efficient method to test and qualify repeater/transmitters.

Abstract: A wireless communication base station apparatus that allows the number of times of blind decodings at a mobile station to be reduced without increasing the overhead caused by notifying information. In this apparatus, a CCE allocation part (104) allocates allocation information allocated to a PDCCH received from modulation parts (103-1 to 103-K) to a particular one of a plurality of search spaces that is corresponding to a CCE aggregation size of the PDCCH. A placement part (108) then places the allocation information in one of downstream line resources, reserved for the PDCCH, that is corresponding to the CCE of the particular search space to which the allocation information has been allocated. A radio transmission part (111) then transmits an OFDM symbol, in which the allocation information has been placed, to the mobile station from an antenna (112).

Abstract: A disclosed base station is used in a radio communication system where sounding reference signals from user terminals are multiplexed using distributed FDMA in which distributed frequency blocks each including frequency subcarriers discretely distributed in a system bandwidth are allocated to the user terminals, and the system bandwidth is repeatedly halved into frequency band segments according to a binary-tree structure.

Abstract: A communications apparatus is provided. A receiving module receives a signal with a predetermined signal bandwidth. A low pass filter filters the signal to obtain a filtered signal. A filter bandwidth of the low pass filter is wide enough to pass the regular sub-carrier frequency components and at least half of the guard sub-carrier frequency components of the signal. An analog to digital converter samples the filtered signal with a sampling rate exceeding a standard sampling rate defined in accordance with the predetermined signal bandwidth of the signal to obtain a plurality of digital samples. A Fast Fourier Transform module performs a fast Fourier transform on a predetermined number of points of the digital samples to obtain a plurality of transformed samples. The predetermined number exceeds a standard number defined in accordance with the predetermined carrier bandwidth. A sub-carrier collector collects the data from the transformed samples.

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: In one embodiment of a communications network, the predetermined encoding scheme and symbol constellation configurations are chosen so that the range in channel qualities that the encoding scheme and symbol constellation configurations are designed to be utilized within overlap with each other. This overlapping provides hysteresis, which reduces the frequency with which a subscriber must alter encoding scheme and symbol constellations. Reducing the frequency of changing encoding scheme and/or symbol constellation eliminates the communication overhead associated with these changes and increases throughput by enabling the subscriber to spend more time transmitting data.

Abstract: It is possible to obtain the diversity effect in a plurality of slots while preventing complication of a scheduler or inefficient use of resources, to eliminate the phenomenon in which SINR significantly decreases in a specific slot, and to avoid deterioration of demodulation performance. In a radio communication system which performs transmission in a sub-frame unit having two slots temporally continuously arranged, when pre-coding is performed by multiplying a signal to be output to a plurality of antennas by a pre-coding weight, CDD is used to shift a phase such that the phase in the pre-coding weight is cyclically changed on the frequency axis. The phase shift amount to be applied by the CDD is set to change by 2? in an allocated resource block (1RB) of the local device, and PVS is applied such that the phase shift amount differs by ? between the weight W0 of the first half slot and the weight W1 of the second half slot in the sub-frame.

Abstract: Techniques for periodically resetting the polar cap for a differential codebook precoding scheme for wireless communications are described. An apparatus may comprise a fixed device for a mobile broadband communications system utilizing an orthogonal frequency-division multiple access technique, the fixed device having a precoding module operative to generate a precoding matrix using a received first codeword of a first base codebook, subsequently reconstruct the precoding matrix using a received polar-cap codeword of a polar-cap codebook, and periodically reset the precoding matrix to clear accumulated error at the fixed device using a received second codeword of a second base codebook. Other embodiments are described and claimed.

Abstract: A method and system of accommodating different mapping schemes in a transmission using an orthogonal direct sequence spread spectrum technique in which input data to a transmitter is spread by conversion into a sequence of complex numbers modulated for N-point discrete Fourier transform (N-point DFT), subcarrier mapping, M-point inverse discrete Fourier transform (M-point IDFT), and cyclic prefix (CP) insertion; the spread and modulated data is transmitted to and received by a receiver; and the received data is despread demodulated for cyclic prefix (CP) removal, M-point discrete Fourier transform (M-point DFT), subcarrier demapping and equalization, and N-point inverse discrete Fourier transform (N-point IDFT).

Abstract: A method, system and communication network for transmitting information signals via uplink (UL) collaborative SDMA, in a wireless communication system. Base station receiver estimates a channel gain associated with the transmission path(s) of each user and keeps a matrix of normalized covariance, between users. Based on the estimated channel gain and the normalized covariance, ULS utility is able to compute channel capacity. Based on capacity estimates of (1) the multiplexed user signals and (2) the individual user signals, signals are either multiplexed for UL SDMA or are transmitted individually. An optimal selection of multiplexed signals may be based upon: (1) a cross user interface measurement; and (2) a selection mechanism based on eigen-decomposition techniques. The ULS utility enables a UL scheduler to pair information signals with clear spatial distinction and minimal correlation, based on capacity evaluations.