Abstract: The present invention provides a time-frequency code spreading method in an OFDMA system. The method includes: converting a transmission message into one or more modulating signal vectors, and each bit of the transmission message is spread onto all vector elements of a modulating signal vector; mapping one or more modulating signal vectors to a set of time-frequency grids, wherein in an OFDMA time-frequency plane, two time-frequency grids to which any two vector elements in each modulating signal vector are mapped do not have the same frequency location or time location. In addition, the present invention also provides a time-frequency code spreading apparatus in an OFDMA system.

Abstract: A method and system for encoding and determining labels in a Dual Polarization (DP) Quaternary Phase Shift Keying (QPSK) signal is provided. A label frame, signature sequence, and data payload are combined using a complementary constant-weight code encoding (CCWC) encoder, the output of which is deinterleaved and differentially precoded to generate a polarized tributary of a DP-QPSK signal. This encoding can be duplicated for a second tributary of the DP-QPSK signal. The label can be determined using one or more polarizers and corresponding low-speed photodetectors, each applied to a copy of the DP-QPSK signal. The strongest output of the photodetectors is then used to determine the label. Alternatively, the DP-QPSK signal can be viewed as having XI, XQ, PH, and PV tributaries. These tributaries can then be translated into XI, XQ, YI, and YQ tributaries are encoded into a standard DP-QPSK signal.

Abstract: A transmit amplifier stage operable to amplify a transmit signal comprises power amplifiers and switches. The power amplifiers include at least one fractional power amplifier operable to provide fractional power to amplify the transmit signal, where the fractional power is a fraction of the full power. A switch has a plurality of positions, where a position directs the transmit signal to a selected power amplifier.

Abstract: Provided are a digital communication system using frequency selective baseband and a method thereof. A transmitter of the digital communication system, includes: a preamble/header transmission processing unit for spreading a preamble for frame synchronization and a header including data information; a data transmission processing unit for spreading data by using spread codes having dominant frequency in a desired frequency band, i.e., frequency selective spread codes; and a multiplexer for multiplexing the spreaded preamble and the spreaded header from the preamble/header transmission processing unit and the frequency selective spreaded data from the data transmission processing unit and transmitting the multiplexed signal in digital.

Abstract: The present invention describes a spread spectrum communication system wherein the frequency of carriers and the code channels of the carriers or both for transmission to a given remote station user vary in time. This provides for a direct sequence spectrum communications system which changes frequency or code channel according to a predetermined pattern. The code channels and frequencies can be determined in accordance with a deterministic function or based upon a subset of the data to be transmitted. A receiver structure is also described for receiving the same.

Abstract: A method is provided for receiving a received signal corresponding to a multicarrier signal transmitted by at least one transmitter via a transmission channel, the multicarrier signal being formed by a temporal succession of symbols including of a set of data elements with real values, including informative data elements, and reference data elements called pilots for at least some of the symbols. The reception method includes step of first estimation of the transmission channel. Due to at least one of the pilots being an isolated pilot in transmission, the reception method further includes a step of extracting the isolated pilot, and a step of locally refining the first estimation.

Abstract: A system, method and apparatus for wireless communications are provided. In an exemplary embodiment, frequency components present in a short duration modulated complex pulse is used to represent data to be sent. In other embodiments, the complex pulse is created, modulated, then modified to have desirable frequency characteristics. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.

Abstract: Provided is a radio communication device which can surely prevent inter-code interference while maintaining the use efficiency of an upstream line control channel and suppress separation characteristic of a response signal. The device includes: a control unit (209) which controls a cyclic shift amount of a ZC sequence used for a primary diffusion in a diffusion unit (214) and a Walsh sequence used for secondary diffusion in a diffusion unit (217) according to a PUCCH number inputted from a judgment unit (208); the diffusion unit (214) which performs primary diffusion of the response signal by the ZC sequence set by the control unit (209); and the diffusion unit (217) which performs secondary diffusion of the response signal by the Walsh sequence set by the control unit (209).

Abstract: Systems (100) and methods (700) for processing a data signal in a communications system. The methods involve generating a first chaotic sequence at a transmitter (102). The methods also involve performing first basis function algorithms using the first chaotic sequence to generate first statistically orthogonal chaotic sequences. At least one sequence is selected from the first statistically orthogonal chaotic sequences for combining with a first data signal. The selected sequence is combined with a second data signal to obtain a modulated chaotic communication signal. The modulated chaotic communication signal is transmitted to a receiver (104). At the receiver, the received modulated chaotic communication signal is processed to obtain data therefrom. Notably, the signal processing generally involves performing a deterministic process (e.g., a Hidden Markov Model deterministic process).

Abstract: Provided are a system and method for human body communication using a limited passband. The system includes a transmission frame generating unit for human body communication which generates a transmission frame for human body communication based on data information including user identification (ID) and data scrambled into an orthogonal code generated by the user ID; a symbol mapping unit for symbolizing the generated transmission frame for human body communication according to a predetermined modulating method; a spreading unit for spreading the symbol outputted in the symbol mapping unit; a waveform generating unit for generating a baseband signal whose band is limited to a predetermined range with respect to the data spread in the spreading unit; and a middle band transmitting unit for modulating the baseband signal into a predetermined limited passband signal.

Abstract: Disclosed are a radio transmission device and a radio transmission method which can reduce a processing amount or a memory amount while maintaining the randomizing effect of other cell interference. When using as a reference signal, a ZC sequence of the sequence length uniquely correlated to a transmission bandwidth of a reference signal, as the transmission bandwidth becomes smaller and the sequence length of the ZC sequence becomes shorter, the sequence is switched at a shorter time interval and as the transmission bandwidth becomes greater and the sequence length of the ZC sequence becomes longer, the switching is performed at a longer time interval. Thus, a reference signal is generated by using the ZC sequence in accordance with the timing into which the reference signal transmission bandwidth and the sequence are switched.

Abstract: Described is a method that includes receiving a signal through a channel; considering at least one channel-related criterion and, in response to the considered at least one channel-related criterion, setting a value of an adaptive combining threshold for a maximum ratio combiner that receives the outputs of a plurality of fingers of a rake receiver.

Abstract: A method for allocation of parameters for radio transmission in a wireless communication network using channel feedback compression is provided. At least one channel impulse response in the time domain for at least one connection (CH13-CH24) between an antenna (A1, A2) of a transmitter (BS) and an antenna of a receiver (MS) is determined. Only the at least one complex coefficient related to one or more time intervals of the at least one channel impulse response with a power higher than a predefined threshold is fed back. Parameters for radio transmission are allocated to the at least one connection (CH13-CH24) based on the at least one channel impulse response which is fed back. Network elements and a wireless communication network associated with the method are also provided.

Abstract: An embodiment for wirelessly communicating a signal includes a transmitter combining a plurality of phase shifted input data signals with a plurality of synchronization/pilot sequences to produce a plurality of combined signals, performing frequency domain-to-time domain transformations of the combined signals to produce a plurality of candidate signals, determining peak-to-average ratios for at least some of the plurality of candidate signals, identifying a selected signal from the plurality of candidate signals based on the peak-to-average ratios, and transmitting the selected signal over a wireless communication channel.

Abstract: Embodiments of methods and apparatus for wirelessly communicating signals include one or more transmitters configured to generate a plurality of wireless signal for transmission. Each of the wireless signals includes a plurality of pilot signals represented in a plurality of unevenly spaced, in-band subcarriers. Pilot signals of each wireless signal are positioned at subcarriers that are orthogonal in frequency with subcarriers at which pilot signals of all other wireless signals are positioned. According to an embodiment, subcarrier indices each the plurality of pilot signals are determined using a third order or higher order polynomial parameterization of pilot subcarriers in conjunction with a convex optimization algorithm to produce pilot signals having near-optimal channel estimate mean square error (MSE) performance. The wireless signals are simultaneously radiated over a wireless communication channel using a plurality of co-located or distributed antennas.

Abstract: A system is provided for transmitting a low code rate spatially multiplexed channel on multiple antennas. The system includes a transmitter and a processor. The processor is configured such that the processor encodes a block of information bits to form channel coded bits, wherein the ratio of the number of channel coded bits to the number of information bits is greater than one; and the processor maps the channel coded bits to modulation symbols, and each channel coded bit is mapped once to a modulation symbol. The transmitter is configured to transmit a first portion of the modulation symbols using a spreading sequence on a first antenna of the multiple antennas and to transmit a second portion of the modulation symbols using the spreading sequence on a second antenna of the multiple antennas.

Abstract: An acquisition module includes a coherent correlator configured to receive a transmission having a pilot signal and correlate the received transmission with a local copy of the pilot signal to produce a first output, a delayed correlator configured to delay the first output and correlate the first output with the delayed first output to produce a second output, and a detector configured to detect the pilot signal in the transmission based on the second output.

Abstract: Communication circuitry uses a combination of Pseudo-Noise (PN) coded and non-PN coded transmission periods to represent different data values. In one embodiment, a number of data values are encoded into a smaller second number of encoded ternary values. The Pseudo-Noise (PN) codes are transmitted representing some of the encoded ternary values and no transmitted PN codes represent other encoded ternary values. The throughput of spread spectrum radio systems is increased by representing data values in fewer spread spectrum time slots.

Abstract: A communication apparatus is connected to a transmission channel for transmitting data to another communication apparatus. The communication apparatus includes: a communication frame generator which generates a communication frame for storing the data; and a controller which controls to insert a pilot symbol into the communication frame based on a state of the transmission channel.

Abstract: Techniques for transmitting data with dynamic space-time coding are described. Dynamic space-time coding refers to the mapping of data across both space and time dimensions based on a mapping scheme that changes in a dynamic manner, e.g., a time-variant manner. A transmitter generates at least one data stream and performs space-time coding on the at least one data stream in a dynamic manner to generate at least two output streams for transmission from at least two antennas. The space-time coding may be performed in various manners. For example, each data stream may be space-time coded based on a respective set of space-time codes, e.g., by cycling through the space-time codes in the code set or by using a space-time code selected based on feedback from a receiver. The code set for each data stream may also be selected from among multiple code sets available for the data stream.

Abstract: A radio transmission apparatus for transmitting a first radio signal and a second radio signal with different communication system, the apparatus includes: a first transmission unit which generates the first radio signal on the basis of a first communication system and transmits the first radio signal; a diffusion processing unit which performs diffusion processing of data allocated to DC subcarrier on the basis of the first communication system, and generate a diffusion signal; an addition unit which adds the diffusion signal and a signal obtained by orthogonal frequency division multiplex processing; and a second transmission unit which transmits the added signal as the second radio signal.

Abstract: The present invention provides an ultra-wide band (UWB) system and method. In one embodiment, a transmitter of a low duty cycled ultra wide band (UWB) system includes a differential spreading encoder for encoding a phase of a bit sequence based on a reference bit sequence. The transmitter also includes a pulse generator for generating a number of pulses associated the bit sequence using the encoded phase of the bit sequence, where the number of pulses is equal to a length of the bit sequence. Moreover, the transmitter includes a DMPSK modulator for generating a modulated signal through modulating the number of pulses using a phase of a differential data symbol.

Abstract: A multi-burst transmitter for ultra-wideband (UWB) communication systems generates a sequence of precisely spaced RF bursts from a single trigger event. There are two oscillators in the transmitter circuit, a gated burst rate oscillator and a gated RF burst or RF power output oscillator. The burst rate oscillator produces a relatively low frequency, i.e., MHz, square wave output for a selected transmit cycle, and drives the RF burst oscillator, which produces RF bursts of much higher frequency, i.e., GHz, during the transmit cycle. The frequency of the burst rate oscillator sets the spacing of the RF burst packets. The first oscillator output passes through a bias driver to the second oscillator. The bias driver conditions, e.g., level shifts, the signal from the first oscillator for input into the second oscillator, and also controls the length of each RF burst.

Abstract: Wireless transmission techniques are described, including techniques used to generate scrambling codes for use in wireless transmissions, such as spread spectrum transmissions. In some embodiments, scrambling codes may be iteratively generated using multiplicative factors. The multiplicative factors may be predetermined and stored in advance, reducing processing time when the codes are needed. The multiplicative factor iterations may involve predetermined algorithms, such as squaring and powers of two iterations.

Abstract: A controlling unit disposed in a PLL circuit controls a phase interpolator to gradually change a phase shift amount applied to a phase shift signal C_PS by a unit of basic delay amount ? at a timing predetermined in accordance with a modulation profile of an SSC. Further, the controlling unit controls a total phase shift amount applied to the phase shift signal C_PS output from the phase interpolator in one period of a feedback clock signal C_FB obtained by dividing frequency of the phase shift signal C_PS in a way that a difference between the total phase shift amount and a total phase shift amount in a previous one period of C_FB is always equal to or less than the basic delay amount ?.

Abstract: A demodulation reference signal generator includes a non-correlation sequence generator to generate a non-correlation sequence for RS of a first resource block; a first spectrum spreading unit to spread spectrums of elements in the non-correlation sequence for RS to be mapped to a first frequency resource of the first resource block, by using a first group of codes; a second spectrum spreading unit to spread spectrums of elements in the non-correlation sequence for RS to be mapped to a second frequency resource of the first resource block, using a second group of Codes; the first and second frequency resources are adjacent frequency resources used for RS transmission in the first resource block, and the first and second groups of Codes are mirrors in column to each other; and a mapping unit to map the spectrum-spread elements to the first and second frequency resources.

Abstract: A modulator being made small in size, low in costs, low in power consumption, small in heat generation and spurious signals. The modulator includes multipliers (101, 102) for code-modulating received transmission data (D(n), C(n)), and outputting the modulated data, a control channel gain factor signal generator (106) for generating a gain control signal, a control channel gain factor signal generator (107), and weighting coefficient setting signal generators (108, 109) for receiving the output of the complex-number computing section (120) and controlling the gains of the raised cosine filters (110 to 113).

Abstract: A data communication method is provided, comprising: processing high-speed digital data for communication to produce processed data; generating short impulse wavelets; constructing a digitally modulated ultra wideband signal from the short impulse wavelets in response to bits of the processed data, wherein the digitally modulated ultra wideband signal comprises a series of the short impulse wavelets, and the value of each bit of the processed data is digitally modulated onto the shape of at least one of the short impulse wavelets of the series, to produce a series of digitally shape modulated impulse wavelets; and transmitting the digitally modulated ultra wideband signal, including the series of digitally shape modulated impulse wavelets, via an antenna.

Abstract: A wireless communication apparatus capable of minimizing the degradation in separation characteristic of a code multiplexed response signal. In this apparatus, a control part (209) controls both a AC sequence to be used in a primary spreading in a spreading part (214) and a Walsh sequence to be used in a secondary spreading in a spreading part (217) so as to allow a very small circular shift interval of the ZC sequence to absorb the interference components remaining in the response signal; the spreading part (214) uses the ZC sequence set by the control part (209) to primary spread the response signal; and the spreading part (217) uses the Walsh sequence set by the control part (209) to secondary spread the response signal to which CP has been added.

Abstract: A signal generating apparatus includes a spreading device that respectively spreads data using spreading code that is based on an initial phase; a multiplexing unit that code multiplexes the data spread by the spreading device; a calculating unit that calculates a peak of a signal resulting from code multiplexing by the multiplexing unit; a changing unit that changes the initial phase of the spreading device in a predetermined order; a determining unit that each time the initial phase is changed by the changing unit, determines whether the peak calculated by the calculating unit is at most a threshold; and a transmission control unit that outputs the signal, if the determining unit determines that the peak is less than or equal to the threshold.

Abstract: Aspects of a method and system for transmitter beamforming for reduced complexity multiple input multiple output (MIMO) transceivers are presented. Aspects of the system may include a MIMO transmitter that computes a channel estimate matrix and decomposes the computed channel estimate matrix based on singular value decomposition (SVD). Singular values in a singular value matrix may be rearranged and grouped to generate a plurality of submatrices. In one aspect, each of the submatrices may be decomposed based on GMD at a MIMO transmitter, while a MIMO receiver may utilize a vertical layered space time (VLST) method. In another aspect, the MIMO transmitter may utilize Givens rotation matrices corresponding to each of the submatrices, while the MIMO receiver may utilize maximum likelihood (ML) detection.

Abstract: The present disclosure proposes a method for precoding of transmission signal at an access point of a multiuse system based on eigenmode selection and minimum mean square error (MMSE) processing. The most reliable eigenmodes of every multiple-input multiple-output (MIMO) channel in the system can be selected at each user terminal and corresponding eigenvalues and eigenvectors can be fed back to the access point. The linear MMSE precoding (beamforming) applied at the access point based on the selected eigenmodes may provide an improved transmission capacity performance.

Abstract: Sequence generation in wireless communication is provided for sequences having good aperiodic correlation properties. In particular, dual window quasi-Barker sequences are generated that possess at least some properties of Barker sequences. In addition, the sequences can be orthogonal to mitigate multiple access interference. Dual windowing allows the sequences even after being phase modulated by data to be recognized, provided that delay in transmission is large as compared to the correlation zone. In this regard, the sequences can be utilized in quasi-synchronous spread spectrum and/or code division multiple access (CDMA) signal communication to provide orthogonality while substantially eliminating inter-user and inter-symbol interference. In addition, unlike the single window low periodic correlation sequences, system overheads, such as cyclic prefix, need not be utilized in transmission as the data modulation effect can be accounted for by the dual windowing.

Abstract: Provided is a system and method of digitally encoding and decoding digital data during the transmission process using a combination of Direct Sequence Spread Spectrum (DSSS) and turbo coding. A DSSS de-spreading process is used in place of the outer decoder functional block of a turbo decoder, which removes the need for a dedicated outer ECC code. Removal of the dedicated outer ECC code allows for an increase in the actual data rate transmitted through the channel (compared with a system which uses a discrete DSSS stage after Turbo coding or some other ECC code) because the number of bits to be transmitted for a given data rate has been reduced.

Abstract: A wireless device comprising a plurality of chips may be operable to dynamically configure wireless communication between the plurality of chips. Each of the chips may include one or more transceivers and one or more integrated directional antennas communicatively coupled to the one or more transceivers. The communications link between chips in the wireless device may be dynamically configured via control of the transceivers and/or the integrated directional antennas. The antennas may include patch antennas and/or dipole antennas. The transceivers may be configured by controlling output power of power amplifiers or by controlling gain of low noise amplifiers. The communications link may be dynamically configured by controlling a characteristic impedance of the antennas for impedance matching to transceivers. A frequency of the communication link may be controlled by configuring the antennas. A bandwidth of the communications link may be configured based on activity of processors in the wireless device.

Abstract: A signature sequence employed in a wireless transmission over a channel is detected and utilized. The signature sequence is selected from a set of sequences formed by delay-Doppler shifts of a base sequence. Preferably but not exclusively, the set of sequences is formed by circular delay-Doppler shifts of the base sequence. The base sequence can be, for example, an m-sequence. A received signal is obtained from a received wireless transmission. A candidate sequence selector (90) selects a candidate sequence from among a set of sequences for evaluation as the signature sequence, the set of sequences having been formed by sequence set generator (88) as delay-Doppler shifts of a base sequence. An image former (82) uses the base sequence and the received signal to form a delay-Doppler image with respect to an image area pertinent to the candidate sequence.

Abstract: The present invention relates to a transmission method for a transmitter having Nt transmit antennas. The method (1) spreads symbols in two dimensions by means of a spreading code, the symbols coming from a signal for transmission over Nfft sub-carriers via the Nt transmit antennas. The signal is transmitted with a power pem(k) that is determined per symbol m, per user k=1, . . . , Nu, and per transmit antenna. The principle of the method (1) is to determine (2) a set of powers pem(k) that is constant over a symbol frame, with the distribution of power amongst the users minimizing an overall error criterion under the constraint that the sum of the powers pem(k) in the set is equal to the product of the number of users multiplied by the average power emitted per symbol over the users.

Abstract: The present invention relates to a method for transmitting data Di in a telecommunication system SYST including a first transceiver TXi and a second transceiver RX linked together by means of a communication channel Chi, one of which transceivers being mobile, which method includes: a spreading step for spreading said data Di over a plurality of components Ctj (for j=1 to M), and an equalization step during which each component Ctj (for j=1 to M) is multiplied by an equalization value Wi(j)* representative of communication conditions within the communication channel Chi. According to the invention, the equalization values Wi(j)* are also representative of a Doppler effect generated by movement of the mobile transceiver. The invention enables to significantly compensate for alterations caused to the communication channel Chi by movement of the mobile transceiver.

Abstract: This disclosure relates to method, device and system for detecting errors in a communication system. A signal is received from a transmitter at a receiver wherein the signal includes a data portion and a result of a hash function. The hash function is computed in part from a transmitter identification code. The receiver determines if the result of the hash function matches both the data portion and the transmitter identification code. The receiver discards the signal if the result of the hash function does not match both the data portion and the transmitter identification code of the transmitter.

Abstract: A method for generating a preamble of a frame for a multiple input multiple output (MIMO) wireless communication begins by, for each transmit antenna, generating a carrier detect field. The method continues by, for a first grouping of the transmit antennas, generating a first guard interval following the carrier detect field; and generating at least one channel sounding field. Continuing, the method applies cyclical shift prior to transmission via the first grouping of the transmit antennas. When the MIMO wireless communication includes more than the first grouping of the transmit antennas, for another grouping of the transmit antennas. For the another grouping of the transmit antennas, generating at least one other channel sounding field. The method proceeds by generating the first guard interval prior to the at least one other channel sounding field, and applying another cyclical shift prior to transmission via the another grouping of the transmit antennas.

Abstract: A code phase signalling module arranged to provide code phase signalling to assist in signal acquisition of direct sequence spread spectrum signalling received by a receiver module from a transmitter module. The code phase signalling is arranged to be used by the receiver module to synchronise the phase of a synchronisation code provided from within the receiver module with the phase of a modulation code of the direct spread spectrum sequence signalling received by the receiver module. The synchronisation code sequence corresponds to the modulation code sequence. The code phase signaling module is arranged to provide code phase time signaling representing the offset time of the synchronisation code from a reference time. The reference time is associated with the time of transmission of a particular reference portion of the modulation code of the direct spread spectrum signaling.

Abstract: A wireless communication apparatus capable of minimizing the degradation of the separation characteristic of response signals to be code-multiplexed. In the apparatus, a control part (209) controls both a ZC sequence to be used for the primary spread in a spreading part (214) and a Walsh sequence to be used for the secondary spread in a spreading part (217) according to the associations between sequences and CCEs established in accordance with the probability of using response signal physical-resources corresponding to CCE numbers. The spreading part (214) performs the primary spread of the response signal by use of the ZC sequence established by the control part (209). The spreading part (217) performs the secondary spread of the response signal, to which CP has been added, by use of the Walsh sequence established by the control part (209).

Abstract: A method for transmitting information using a sequence is disclosed. According to an embodiment, the method includes the steps of generating a sequence for transmitting data or control signals, performing phase modulation for indicating additional information on partial elements among a plurality of elements configuring the sequence, and transmitting the phase modulated sequence.

Abstract: A method of encoding a signal to be transmitted from a terminal via a channel in a communication network includes receiving the signal at the terminal; determining characteristics of the channel; encoding a first portion of the signal in accordance with a first encoding method to produce a first encoded signal portion; and encoding a second portion of the signal in accordance with a second encoding method to produce a second encoded signal portion. The first portion of the signal encoded in accordance with the first encoding method is dependent on the determined characteristics of the channel. The first encoded signal portion and the second encoded signal portion are transmitted via the channel.

Abstract: A code division multiplex signal transmitter includes an operational circuit, a modulator unit and a multiplexer. The operational circuit adds up input transmission data on channels to produce resultant added data and modulates pieces of bit transmission data which are indicative of the values of the respective bits of the added data, when expressed in binary form, the pieces of bit transmission data being equal in number to the M bit positions of the added data expressed in binary form. The modulator unit includes modulators corresponding in number to the M bit positions of the added data in the binary form. A k-th modulator, where k is an integer of 1 to M, inclusive, modulates a k-th piece of bit transmission data to produce a k-th bit modulated signal whose amplitude level is 2k-1. The multiplexer multiplexes first to M-th bit modulated signals to produce a code division multiplex signal.

Abstract: A transmitter system includes a processor that synthesizes a randomly varying, non-differentiable waveform by applying independent, pseudo-random variations to a number of transmission parameters to produce a number of independent pseudo-random variable stochastic processes with independent distributions within the waveform. Examples of transmitter parameters that can be varied include: a PN spreading sequence segment; a PN spreading symbol rate; a chip clock frequency; a chip frequency-dwell period; a data symbol rate; a data symbol rate dwell; an RF carrier frequency; and a carrier frequency dwell-time.

Abstract: Provided is a radio communication device which can suppress inter-code interference between an ACK/NACK signal and a CQI signal which are code-multiplexed. A diffusion unit (214) diffuses the ACK/NACK signal inputted from a judgment unit (208) by using a ZC sequence. A diffusion unit (219) diffuses the CQI signal by using a cyclic shift ZC sequence. By using a Walsh sequence, a diffusion unit (216) further diffuses the ACK/NACK signal which has been diffused by using the ZC sequence. A control unit (209) controls the diffusion unit (214), the diffusion unit (216), and the diffusion unit (219) so that the minimum value of the difference between the CQI signals from a plurality of mobile stations and a cyclic shift amount of the ACK/NACK signal is not smaller than the minimum value of the difference between the cyclic shift amounts of the ACK/NACK signals from the plurality of mobile stations.

Abstract: Examples are disclosed for transmitting and receiving schemes for multiuser single-carrier space time spreading (STS) with frequency domain equalization.

Abstract: The present invention provides a method for estimating a ratio of average chip energy to a total transmit power spectrum density (Ec/Ior), including: according to a group of spreading codes corresponding to an acquired spreading factor, obtaining an estimated value of Ior; according to a spreading code of a physical channel to be estimated, obtaining an estimated value of Ec; and according to the estimated value of the Ior and the estimated value of the Ec, obtaining an estimated value of EC/Ior. The present invention further provides a device for estimating Ec/Ior. By adopting the method and device for estimating Ec/Ior, when a base station adjusts transmit power of each physical channel, an adjusted value of Ec/Ior can be obtained in real time for accurate estimation.

Abstract: Embodiments of the present invention provide a pilot sending method and an apparatus, which relate to the communication field and can save network resources. The solution is: performing spreading on at least two signature sequences by using a spreading code, where each signature sequence of the at least two signature sequences corresponds to at least one user equipment (UE), and is used as a dedicated pilot of at least one data stream of the at least one UE, and the dedicated pilot is used by the UE to perform precoding matrix estimation; and performing precoding on the spread signature sequences, and sending the precoded spread signature sequences to the UE. The embodiments of the present invention are applicable to the sending of pilots in MU-MIMO.