Abstract: Embodiments of the present invention provide a method, device, and system for sending channel state information. The method for sending channel state information includes: setting number of bits used for quantizing a relative received power value; sending the number of bits to a user equipment UE; receiving a received power codebook index value; determining a received power codebook element corresponding to the received power codebook index value; and processing a signal according to the corresponding received power codebook element.

Abstract: Techniques are provided for transmitting and receiving a mother code in an incremental redundancy hybrid automatic repeat-request protocol. A set of information bits corresponding to a message may be encoded and interleaved to produce the mother code. Each bit position of the mother code may be mapped to an output symbol, and each output symbol may be mapped to an antenna for transmission. One or more transmissions of symbols contained in the output symbols may be performed, where each transmission may include puncturing the mother code by selecting one or more symbols from the of output symbols, and transmitting each symbol in the one or more symbols on an antenna corresponding to that symbol. The mother code may be decoded, in part, by determining combinable bits contained within a set of received symbols, and computing one or more log-likelihood ratio values corresponding to each symbol in the set of received symbols.

Abstract: Pilot symbols transmitted from different sectors of a same base station are multiplied with a same cell specific scrambling code and a first code having low cross correlation and second codes having low cross correlation. The second code is constant over the length of the first code, but may vary for repetitions of the first code.

Abstract: A device for updating complex channel gain estimates for orthogonal frequency division multiplexed (OFDM) symbols that includes a receiver to receive a plurality of OFDM symbols, wherein each OFDM symbol includes a plurality of pilot tones at a subset of odd positions and a finite impulse response (FIR) filter. The FIR filter configured to filter a plurality of initial channel estimates of odd tones of an OFDM symbol using a first set of coefficients to generate an updated estimate of the channel estimates of the plurality of odd tones for that OFDM symbol, and filter the plurality of the initial channel estimates of the odd tones of the OFDM symbol using a second set of coefficients to generate estimates for a plurality of initial channel estimates of even tones for that OFDM symbol.

Abstract: Systems, methods, devices, and computer program products are described for discontinuous multi-carrier uplink management in a wireless communication system. Common timing parameters may be identified for use in relation to discontinuous uplink transmissions on each of a two or more wireless carriers concurrently transmitting from an access terminal. A first operational state is associated with a first wireless carrier, while a second, different state is associated with a second wireless carrier. The first carrier may be operated in the first operational state concurrently with the second carrier being operated in the second operational state, with each carrier operated in accordance with the common timing parameters.

Abstract: The disclosure discloses a multi-antenna signal processing method in an uplink system. The method includes that: after scrambling, modulation, layer mapping, pre-coding, transmission pre-coding, resource mapping and Single Carrier Frequency Division Multiple Access (SC-FDMA) signal generation are performed successively on a coded bit sequence corresponding to each codeword, a resulted signal is transmitted from each transmitting antenna port. The disclosure also provides a multi-antenna signal processing device in an uplink system. With the method and the device according to the disclosure, a lower Peak-to-Average Power Ratio (PAPR) or Cubic Metric (CM) of a signal to be sent can be ensured without imposing any constraint on a pre-coding matrix, thus reducing the cost and power consumption of a terminal whiling increasing transmission performance of the system.

Abstract: A receiver apparatus includes a first receiver having an input for receiving a first version of a signal received by a first receive antenna. The receiver apparatus further includes a second receiver having an input for receiving a second version of the same signal received by a second receive antenna. The first receiver includes a first constellation demapper for demapping constellation symbols generated in the first receiver into a first soft decision bitstream and the second receiver includes a second constellation demapper for demapping constellation symbols generated in the second receiver into a second soft decision bitstream. A combiner is configured to combine the first soft decision bitstream and the second soft decision bitstream to provide a combined soft decision bitstream.

Abstract: The present invention provides an advantageous transmitter apparatus and associated method, for generating a Single-Carrier Discrete Cosine Transform (SC-DCT) OFDM signal for transmission. These transmit-side innovations include circuit configuration and signal processing methods for mapping Ku “input subcarriers” to N “output subcarriers,” where the “output subcarriers” are some or all of the subcarriers defined for the SC-DCT OFDM signal. In one or more embodiments, Ku is less than N, and the mapping is based on advantageous DCT/IDCT precoding. The present invention additionally or alternatively includes advantageous frequency-selective mapping, and further provides a corresponding receiver apparatus and associated method, for receiving and de-mapping the SC-DCT OFDM signals contemplated herein.

Abstract: A method for equalizing a frequency-selective transmission channel (103) with N inputs and MR outputs is shown, the transmission channel representable in a transformation domain based on N orthogonal sub-carriers, and wherein the transmission characteristics from the MT inputs to the MR outputs for each of the N respective orthogonal sub-carriers are represented by N respective sub-carrier channels (201), the method using (904) equalization filters (301, 302) for at least two of the N sub-carrier channels, wherein at least one set (501) of sub-carrier channels comprising at least two of the N sub-carrier channels is formed (901), wherein for at least one sub-carrier channel, a first-type equalization filter is used that is determined (902) based on a representation of at least one sub-carrier channel, and wherein for at least one sub-carrier channel, a second-type equalization filter is used that is derived (903) at least partially from the first-type equalization filter.

Abstract: An outdoor communication unit (ODU) for implementation within a dual channel microwave backhaul system, is provided. The ODU includes an radio frequency (RF) module, having digital capabilities, which is configured to utilize the digital capabilities to perform adaptive adjustments to correct errors in data in a digital domain, a conversion block configured to convert the data between an analog domain and the digital domain, and a processing module configured to adaptively adjust a characteristic of the data and a characteristic of a dual channel wireless link, and to facilitate a transmission of the data over the dual channel wireless link by performing mathematical manipulation techniques. In particular, the characteristic of the data and of the dual channel wireless link are adaptively adjusted, according to a detected condition, using a hitless adaptive coding modulation (ACM) technique to optimize the transmission of the data over the dual channel wireless link.

Abstract: There is provided a method of transmitting control information in a Wireless Local Area Network (WLAN) system, comprising transmitting first control information by means of cyclic shift delay diversity beam-forming and transmitting second control information. The first control information comprises information necessary for each of a plurality of target stations of the second control information to receive the second control information. The second control information beamformed and transmitted to the plurality of target stations.

Abstract: A method and system for improving closed loop feedback in transmit diversity communication. In one embodiment of the invention, a predetermined variation of one or more transmit diversity parameters is performed at the transmit diversity transmitter. The receiver compares the transmit diversity parameter values of the received signals to the predetermined variation and transmits to the transmitter a value of a transmit diversity correction parameter. The transmitter may use this correction value to modify the transmit diversity parameter in a subsequent transmission.

Abstract: Systems, methods, devices, and computer program products are described for transmission of downlink channel quality information and acknowledgment information in a multi-carrier wireless communication system. Channel quality information may be estimated for a number of downlink carriers. An uplink control channel may be configured in a flexible manner based on the number of activated carriers and whether those carriers are configured with MIMO. The feedback cycle for the channel quality information may remain constant.

Abstract: A system is provided for optimizing throughput in a communication system. During operation, the system receives, at a first antenna, estimated channel state information (CSI) at least one channel between the first antenna and at least one second antenna. The system obtains antenna correlation information associated with the first antenna and the second antenna, respectively. The system further calculates a set of noise terms associated with random noise for the at least one channel, and optimizes a configuration of beamformers for the first antenna and the at least one second antenna that maximizes a throughput of all antennas, in accordance with the estimated CSI, the obtained antenna correlation information, and the noise terms.

Abstract: A transmission method for simultaneously transmitting a first modulated signal and a second modulated signal at the same frequency includes performing precoding on both signals using a fixed precoding matrix and regularly changing the phase of at least one of the signals. In this method, the power ratio between a plurality of signals transmitted from a plurality of antennas at the same frequency and at the same time differs from the power ratio between a plurality of pilot signals transmitted from the plurality of antennas at the same frequency and at the same time, whereby the accuracy of channel estimation by a reception device is improved.

Abstract: The present invention relates to a refinement of the Alamouti encoding scheme. The Alamouti scheme provides transmitting in a first period, the symbols S1 and S2 and in the next period the symbols—S2* and S1*, wherein S1* is the complex conjugate of S1. The symbols carrying the same information are transmitted on different paths to a receiver. If a disturbance occurs during the first period, the receiver may recover the symbol from symbol S1* in the second time period and vice versa. If no disturbance occurs, the receiver may use both symbols to further improve the transmission quality. An interleaver is provided to increase the transmission distance between redundant symbols, thereby causing the spread delay to be set to a value larger than the maximum length of typical channel disturbance in the communication channel.

Abstract: In a wireless network, plural downlink signals from plural base stations are transmitted to a terminal. The plural downlink signals all carry the same information to the terminal. The terminal provides feedback on the downlink channels. The feedback provides information on the taps of the channels. The amount of information fed back is constrained. Based on the feedback, transmission parameters of the downlink signals are adjusted. The process of transmitting, providing feedback, and adjusting the parameters continue so that the energy of the downlink signal is enhanced at the terminal location and suppressed elsewhere. Beam forming can be used to further suppress the energy signature at locations other than the terminal location.

Abstract: A method of transmitting a training signal in a Wireless Local Area Network (WLAN) system includes generating one or more first training signals for a first destination station and one or more second training signals for a second destination station by applying a mapping matrix P to a training signal generation sequence, mapping the first training signals and the second training signals to a plurality of antennas according to an antenna mapping matrix, and performing Inverse Fast Fourier Transform (IFFT) on each of the first training signals and the second training signals mapped to the plurality of antennas and transmitting the training signals through the plurality of antennas.

Abstract: A receiving device according to the present invention includes: a receiver for receiving an OFDM symbol that is modulated by phase shift keying; an FFT processor for applying an FFT process to the received OFDM symbol to obtain a subcarrier signal; a demapping unit for demapping the subcarrier signal to generate a bit string; a norm calculator for calculating the norm of the subcarrier; a weighting factor generator for generating a weighting factor by taking the statistics of the calculated norm; and a weighting unit for obtaining a soft decision value by weighting the bit string after demapping, based on the particular weighting factor. Thus, the receiving device can obtain a soft decision value to achieve good decoding performance with a small number of known signals and processes.

Abstract: The disclosure provides a method and device for retransmitting data under antenna gain imbalance, and the method includes: determining that gains of multiple antennas at a transmission terminal are imbalanced; using a better spatial sub-channel in the multiple antennas to retransmit data when streams transmitted by the multiple antennas adopt a same Modulation and Coding Scheme; and using a better spatial sub-channel in the multiple antennas to retransmit data and/or using a single-stream approach to retransmit data when the streams transmitted by the multiple antennas adopt different Modulation and Coding Schemes. The disclosure selects a corresponding retransmission approach according to the condition of a spatial sub-channel on which streams have an error, thus improving and ensuring success rate for retransmitting a stream.

Abstract: A precoding codebook matrix/vector of length 2L is generated by the selection of two matrices/vectors, each from one of a predetermined set of L×L matrices and multiplying each column of one of the matrices/vectors by a complex coefficient.

Abstract: Compressive sampling is used to generate pilot symbols to be transmitted over an array of antennas in a MIMO wireless communications device. A pilot symbol is transmitted over the array of antennas according to a spatially randomized antenna transmission function that randomly changes across the array of antennas. The randomized antenna transmission function may randomly select/deselect antennas and/or randomly change amplitude and/or phase of the pilot symbol transmission. Channel estimates can be constructed at a receiver based on the spatially randomized pilot symbols that were transmitted.

Abstract: The antenna weight selection solution disclosed herein selects antenna weights for a multiple antenna communication system that transmits uplink or downlink data using multiple radiation patterns based on channel variability metrics determined for two or more sets of candidate antenna weights. In so doing the antenna weight selection solution disclosed herein reduces the channel variability associated with data transmissions, and therefore reduces the amount of feedback and/or the feedback rates required for the multiple antenna communication system.

Abstract: Power control for devices having multiple transmit antennas are disclosed, including power control methods for Physical Uplink Control Channel (PUCCH) and Sounding Reference Signal (SRS) transmissions for a wireless transmit/receive unit (WTRU). The PUCCH and SRS power control methods include selecting a multiple input multiple output (MIMO) mode and changing the power of the PUCCH or SRS transmission based on the selected MIMO mode. Another power control method estimates an antenna gain imbalance (AGI) for a WTRU having at least two transmit antennas. The AGI is based on measuring a Reference Signal Received Power (RSRP) on each transmit antenna. Each transmit antenna is then scaled by an AGI scaling factor based on the estimated AGI.

Abstract: Transmission outputs of a plurality of transmission branches (101, 102) are extracted by coupler sections (161, 162). Branch detectors (121, 122) respectively detect the levels of the extracted signals of the respective transmission branches and a combination detector (130) detects an output obtained by combining two extracted outputs from the transmission branches by a signal combining section (110). An amplitude error is detected and corrected by comparing output levels of the branch detectors (121, 122), and a phase error is detected and corrected by an output level of the combination detector (130).

Abstract: Systems are provided for searching for a codeword from a plurality of codewords in a codebook for use in precoding, for example, as used in a multiple-input multiple-output (MIMO) transmission system. Dimension reduction techniques may be utilized to reduce the complexity and enhance the efficiency of the codebooks search. Null-spaces of an optimal codeword and codewords in a codebook may be computed. Distance values may be computed based on the null=spaces of the codewords. A codeword may be selected from the codebook based on a minimum distance value from the optimal codeword.

Abstract: A method for transmitting a sounding reference signal from a user equipment in a MIMO antenna wireless communication system. The method includes receiving sounding reference signal setup information from a base station, the sounding reference signal setup information including an initial cyclic shift value nSRScs and an initial transmissionComb parameter value kTC; setting an interval between cyclic shift values corresponding to each antenna port based on the initial cyclic shift value, to reach a maximum interval; setting a transmissionComb parameter value corresponding to a specific one of the antenna ports to a value different from the initial transmissionComb parameter value if the initial cyclic shift value is a previously set value and the number of antenna ports is 4; and transmitting the sounding reference signal to the base station through each antenna port by using the set cyclic shift value and transmissionComb parameter value.

Abstract: A transmitter 103 and a method therein for transmitting discovery signals to a receiver 107. The transmitter 103 and the receiver 107 arc comprised in a radio communications system 100. The transmitter 103 transmits two or more discovery signals over two or more directions, wherein the each discovery signal is configured to span over a fraction of a carrier bandwidth.

Abstract: A data transmission method and system are provided. The data transmission method includes: transmitting, by a BBU, frequency domain data obtained by performing a multi-antenna MIMO coding, to a RRU via a CPRI; receiving, by the RRU, the frequency domain data transmitted by the BBU, via the CPRI; and performing, by the RRU, an OFDM symbol generation processing on the frequency domain data received via the CPRI, to convert the frequency domain data into time domain data. With this method, a rate of the CPRI can be significantly lowered, and a bandwidth of the CPRI can be dynamically adjusted in the communication system according to the load and the usage of frequency resources, thereby lowering the bandwidth of the CPRI.

Abstract: Systems and methods for efficiently transmitting information over a wireless network segment are provided herein. An exemplary method may include separating, via a transmitter, digital fronthaul data into general information and radio signal information, transmitting the general information over the wireless network segment from the transmitter to a receiver on a first communications channel, and transmitting the radio signal information over the wireless network segment from the transmitter to the receiver on a second communications channel.

Abstract: A system for determining precoding for a wireless signal may include a derivation module and a selection module. The derivation module may be configured to determine precoding information for a composite channel. The composite channel may represent characterizations of multiple wireless paths established between multiple receiving antennas and multiple transmitting antennas. The transmitting antennas may be distributed among multiple transmission points. The selection module may further be configured to select a codeword for each transmission point from a subset of predefined codewords based on the precoding information. The codeword for each transmission point may be used to manipulate data signals sent over the wireless paths established between the receiving antennas and the transmitting antennas of the respective transmission point.

Abstract: Transmission quality is improved in an environment in which direct waves dominate in a transmission method for transmitting a plurality of modulated signals from a plurality of antennas at the same time. All data symbols used in data transmission of a modulated signal are precoded by hopping between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol in the frequency domain and the time domain all differ. A modulated signal with such data symbols arranged therein is transmitted.

Abstract: Systems, methods, apparatuses, and computer program products for an interleaved multi-beam acquisition waveform providing concurrent beam selection, automatic gain control (AGC) and automatic frequency correction (AFC) are provided. The access point (AP) may send an acquisition waveform on multiple beams, then return and retransmit an AFC on the multiple beams thus interleaving beam switching with the acquisition and frequency correction waveforms. AGC correction can be deferred until the end, relying on the fact that the transmitter may be detected at close range using a one of the multi-beams that is attenuated.

Abstract: Disclosed is a method of transmitting dual digital signals through a single antenna. The method includes receiving, by a transmitter, a first data stream and a second data stream which use the same carrier frequency, modulating, by the transmitter, each of the first data stream and the second data stream, lowering, by the transmitter, a power level of the modulated second data stream, combining, by the transmitter, the modulated first data stream and the second data stream with the lowered power level, and transmitting, by the transmitter, the added first data stream and second data stream to a single antenna in the same channel.

Abstract: A method for mapping signals to subcarriers in a sending means of a MIMO-based wireless telecommunication network and an apparatus for the same. It is characterized in that, controlling the mapping of the signals in an input signal sequence to the subcarriers, so that the signals sent by different antennas at the same time correspond to nonadjacent signals in the input signal sequence. With the aid of the present invention, burst error due to deep fading channel can be effectively avoided, and diversity gains can be also improved.

Abstract: Systems and methodologies are described that facilitate utilizing dedicated reference signal in connection with downlink transmissions. A dedicated reference signal can comprise a set of dedicated reference symbols, which are inserted into a resource block in accordance with a specification provided by a dedicated reference signal structure. The dedicated reference signal structure can vary according to a rank utilized in the downlink transmission.

Abstract: The present invention relates to a method including signalling by a receive node at least one first transmission rank r to a transmit node, where 1?r ?R, wherein R is a maximum available rank for a transmission, and at least one predefined precoding matrix corresponds to the first transmission rank r, determining by the transmit node a second transmission rank r? for transmitting data from the transmit node to the receive node, where 1?r? ?R, defining at least two subsets of precoding matrices for at least one of the at least one first transmission rank r, selecting one of the at least two subsets of precoding matrices in accordance with a channel quality estimate for a radio channel, and signalling the selected one subset of precoding matrices, wherein the selected one subset of precoding matrices is associated with said the at least one predefined precoding matrix.

Abstract: A station in a wireless communication system includes a processor circuitry configured to form at least a first plurality of data streams and a second plurality of data streams, and a digital precoder configured to receive the first plurality of data streams and the second plurality of data streams. The wireless station can further include a plurality of radio frequency (RF) beamforming chains connected to the digital precoder and configured to form at least one RF envelope, wherein the digital precoder is configured to steer a plurality of digital beams within the at least one RF beam envelope, the digital beams forming a plurality of spatially distinct paths for the first plurality of data streams and a plurality of spatially distinct paths for the second plurality of data streams, and a plurality of antennas operably connected to the RF beamforming chains.

Abstract: An exemplary system comprises at least one antenna, first and second signal paths, and an N-plexer. The antenna may be configured to receive first and second diversity receive signals. The antenna is further configured to transmit first and second diversity transmit signals. The first signal path may have a frequency converter configured to downconvert the first diversity receive signal to an intermediate frequency and to upconvert the first diversity transmit signal to a radio frequency. The second signal path may have a frequency converter configured to downconvert the second diversity receive signal to an intermediate frequency and to upconvert the second diversity transmit signal to the radio frequency. The N-plexer may be configured to provide the first and second diversity receive signals to a cable and to provide from the cable the first and second diversity transmit signals to the first signal path and the second signal path, respectively.

Abstract: For example in case of an OFDM multicarrier transmission system the transmission characteristics of subcarriers of a multicarrier transmission system using a plurality of antenna elements (3, 3?) can be adjusted. Particularly the power and the phase of the subcarriers can be adapted. To this object the subcarrier frequency channel (2, 2?) characteristics of the multicarrier transmission are detected (11, 11?) at the side of the transmitter (3). The power of each subcarrier is then distributed by a weighting unit (14, 14?). The subcarriers can be further pre-equalized (1, 1?) by dividing the subcarrier signal respectively by the sum of the squared magnitude of the frequency channel characteristics of all subcarrier signals or a frequency characteristic of the selected antenna element (3, 3?).

Abstract: A method for providing information of access point (AP) selection in a wireless local area network (WLAN) system, the method including receiving from candidate APs the AP selection information including channel correlation information for other stations associated with the candidate APs; and selecting one AP from candidate APs according to the channel correlation information corresponding to the candidate APs. Accordingly, a gain of multi-user multiple input multiple output (MIMO) can be increased, and an AP suitable for a terminal can be selected.

Abstract: A method for symbol detection includes assigning a received symbol to at least one particular candidate symbol of a set of candidate symbols of a finite candidate symbol alphabet based on a metric between the received symbol and the at least one particular candidate symbol, the metric comprising contributions with respect to channel-based information and contributions with respect to a priori information.

Abstract: The present invention employs a pilot scheme for frequency division multiple access (FDM) communication systems, such as single carrier FDM communication systems. A given transmit time interval will include numerous traffic symbols and two or more short pilot symbols, which are spaced apart from one another by at least one traffic symbol and will have a Fourier transform length that is less than the Fourier transform length of any given traffic symbol. Multiple transmitters will generate pilot information and modulate the pilot information onto sub-carriers of the short pilot symbols in an orthogonal manner. Each transmitter may use different sub-carriers within the time and frequency domain, which is encompassed by the short pilot symbols within the transmit time interval. Alternatively, each transmitter may uniquely encode the pilot information using a unique code division multiplexed code and modulate the encoded pilot information onto common sub-carriers of the short pilot symbols.

Abstract: The present invention relates to a method for communicating from a primary station with an array of transmit antennas to a secondary station on a downlink channel, said method comprising steps of, at the primary station, (a) configuring the downlink channel, step (a) being subdivided into steps of: 5 (a2) computing a precoding to be applied during a corresponding transmission from the primary station to the secondary station for each of an array of transmit antennas; (a3) applying a reversible transform to the precoding, thus ascertaining a set of precoding coefficients substantially representative of the precoding in a transform 10 domain; (a4) computing a set of parameters comprising at least one parameter, said parameter being substantially representative of the coefficients obtained at step (a3); (a5) signaling the set of parameters to the secondary station; 15 (b) transmitting data to the secondary station substantially according to the precoding computed at step (a2).

Abstract: Disclosed is a precoding method comprising the steps of: generating a first coded block and a second coded block with use of a predetermined error correction block coding scheme; generating a first precoded signal z1 and a second precoded signal z2 by performing a precoding process, which corresponds to a matrix selected from among the N matrices F[i], on a first baseband signal s1 generated from the first coded block and a second baseband signal s2 generated from the second coded block, respectively; the first precoded signal z1 and the second precoded signal z2 satisfying (z1, z2)T=F[i](s1, s2)T; and changing both of or one of a power of the first precoded signal z1 and a power of the second precoded signal z2, such that an average power of the first precoded signal z1 is less than an average power of the second precoded signal z2.

Abstract: A method for transmitting a pilot signal for machine to machine (M2M) communication in a wireless communication system and an apparatus thereof are disclosed. The method comprises the steps of configuring a basic unit including a plurality of pilot resource elements (REs) and data resource elements; allocating pilot signal to the plurality of pilot resource elements to the basic unit; and transmitting the basic unit to a receiver in a subframe unit in accordance with a rule which is previously defined, wherein the resource elements are time-frequency resources defined by one symbol index and one subcarrier index, and the basic unit is transmitted at a subframe except for a subframe at which a control channel is transmitted.

Abstract: Provided is a transmitter for transmitting signals by means of the STBC method or the DSTBC method, wherein communication is carried out effectively. The transmitter for transmitting signals by means of the STBC method or the DSTBC method has the following configuration. A frame in which synchronization words are arranged at specified positions is used. An encoding means in the transmitter encodes the entire frame to be transmitted including the synchronization words, by means of the STBC method or the DSTBC method. It is also possible to implement a communication system and a communication method for communicating signals by means of the STBC method or the DSTBC method.

Abstract: A receiving station receives an orthogonal frequency division multiplexing (OFDM) symbol via a shared medium, the OFDM symbol comprising a first set of frequency components modulated with preamble information and a second set of frequency components modulated with information. The receiving station processes sampled values of the received OFDM symbol based on channel characteristics estimated from the first set of frequency components to decode information encoded on a first subset of the second set of frequency components. The receiving station processes sampled values from the first symbol based on channel characteristics estimated from the first set of frequency components and the first subset of the second set of frequency components to decode information encoded on a second subset of the second set of frequency components.

Abstract: A method for transmitting signals in a multi-carrier radio transmission system is provided. The method includes a transmission block composed of N consecutive Orthogonal Frequency-Division Multiplexing (OFDM) symbols in a time domain and M consecutive physical sub-carriers in a frequency domain, where N and M are each an integer not less than 1. The method further includes encoding and interleaving data at a transmitting end, transmitting a pilot signal in a frequency area of a pilot stream for transmission of the pilot signal, performing, at the transmitting end, an IFFT operation on the encoded and interleaved data and the pilot signal, and transmitting, at the transmitting end, the data and the pilot signal through at least one antenna after inserting a preamble signal, wherein at least one pilot stream exists at the transmitting end, and wherein at most one pilot signal is transmitted in a group of OFDM symbols.

Abstract: A method and apparatus of reducing interference in space frequency block coding (SFBC) communication are disclosed. SFBC encoding is performed on at least one pair of symbols. The symbols are assigned to subcarriers in accordance with a frequency assignment pattern assigned to a cell. Different frequency assignment patterns are assigned to neighboring cells. Cells in the network may be divided into a plurality of groups and a different frequency assignment pattern may be assigned to each group of cells. The frequency assignment pattern may be defined such that subcarriers mapped to a pair of symbols in one cell are interlaced to subcarriers mapped to a pair of symbols in a neighbor cell. Alternatively, the frequency assignment pattern may be defined such that subcarriers mapped to a pair of symbols in one cell are shifted in a neighbor cell.