Abstract: A data processing apparatus maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit.

Abstract: Systems and methods of controlling characteristics of messages in sub-1 GHz networks (e.g., IEEE 802.11ah networks) are disclosed. One or more data structures indicating available frame formats and/or timing parameters may be stored at or accessible to transmitters and receivers. The data structures may be organized based on a frame format, a wireless network bandwidth, and/or the number of spatial streams in use at the wireless network. Information stored in the data structures may be used in generation and processing of messages communicated via the sub-1 GHz network.

Abstract: A method and apparatus are provided for reducing a channel length. The method implements a channel-length reduction filter that takes into account a pulse response of the channel. The method includes the following steps: cutting the filter into at least one first and one second portion; optimizing said first portion of the filter according to a first criterion in order to output a first set of filtering coefficients; reducing the length of the channel by optimizing said second portion of the filter according to a second criterion different from the first one and based on the first set of filtering coefficients of said first portion of the filter in order to output a second set of filtering coefficients.

Abstract: Multiple-Input and Multiple-Output (MIMO)-Orthogonal Frequency Division Multiplexing (OFDM) communication is provided which allows high accuracy estimation of frequency offset, high accuracy estimation of a transmission path fluctuation and high accuracy synchronization/signal detection. Pilot symbol mapping is provided for forming pilot carriers by assigning orthogonal sequences to corresponding subcarriers among OFDM signals which are transmitted at the same time from respective antennas in the time domain. Even when pilot symbols are multiplexed among a plurality of channels (antennas), this allows frequency offset/phase noise to be estimated with high accuracy.

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: Provided are, among other things, systems, apparatuses, methods and techniques for converting a discrete-time quantized signal into a continuous-time, continuously variable signal. An exemplary converter preferably includes: (1) multiple oversampling converters, each processing a different frequency band, operated in parallel; (2) multirate (i.e., polyphase) delta-sigma modulators (preferably second-order or higher); (3) multi-bit quantizers; (4) multi-bit-to-variable-level signal converters, such as resistor ladder networks or current source networks; (5) adaptive nonlinear, bit-mapping to compensate for mismatches in the multi-bit-to-variable-level signal converters (e.g., by mimicking such mismatches and then shifting the resulting noise to a frequently range where it will be filtered out by a corresponding bandpass (reconstruction) filter); (6) multi-band (e.g.

Abstract: Disclosed are a wireless communication method of improving frequency efficiency based on a channel function in a wireless communication system and an apparatus thereof. The wireless communication system using a digital modulation scheme, includes: a transmitting apparatus which modulates a data signal to generate a modulation symbol, generates a channel symbol function corresponding to the modulation symbol, combines the modulation symbol with the channel symbol function to generate a transmission symbol to transmit the generated transmission symbol through a transmission antenna; and a receiving apparatus which receives the transmission symbol through a reception antenna, estimates a channel symbol function included in the transmission symbol, and extracts the data signal based on the modulation symbol included in the transmission symbol.

Abstract: Reader receivers including a sample clock providing unit are provided. The sample clock providing unit may be configured to generate a plurality of first clock signals of equivalent frequency that are out-of-phase relative to each other and further configured to generate first and second sample clock signals of unequal phase from selected ones of the plurality of first clock signals by comparing a respective phase of each of the plurality of first clock signals against a phase of a reference clock signal.

Abstract: Bit permutation to bits of a codeword is performed such that: at least one spatial-multiplexing block is made up of bits from B/2 different cyclic-blocks; each constellation word of the at least one spatial-multiplexing block is made up of bits from Bt/2 different cyclic blocks, Bt being the number of bits of the constellation word; and each of the bit pairs of the constellation word is made up of bits from a common one of the Bt/2 different cyclic blocks.

Abstract: Provided is a vector selection modulation-based multi-antenna transmission method, including: for a group of data to be transmitted, using part of bit information in the group of data to select a weight corresponding to the group of data from K preconfigured weights; and performing constellation mapping modulation on residual bit information in the group of data, and using the selected weight corresponding to the group of data to weight the group of data after the constellation mapping modulation, wherein, the K is a natural number. Based on the method of the present document, the spectrum efficiency of the system can be greatly improved under the condition without adding a transmission antenna.

Abstract: A transmitter is capable of suppressing a PAPR to be low and efficiently amplifying transmit power. The transmitter generates a transmission signal by oversampling a modulated signal, and includes a modulation unit that performs a modulation process on an information sequence and that generates a constant envelope signal and a phase interpolation unit that inserts a predetermined number of signals identical in amplitude to signal points of the constant envelope signal between the signal points so that signal points including original signal points are located equidistantly.

Abstract: A transmitter and/or receiver for performing frequency domain equalization is provided. A transmitter includes a pilot position determination unit for determining positions for inserting pilots in a frequency domain based on frequency spectrums of data, and a pilot insertion unit for inserting the pilots between the frequency spectrums of the data according to the determined positions for inserting the pilots.

Abstract: Transport of differential signals is provided. In one aspect, a telecommunications system includes a first unit and a second unit. The first unit can calculate a differential signal from an original signal. The differential signal can represent a change in signal levels between constant time intervals in the original signal. The second unit can estimate the original signal from the differential signal received from the first unit over a communication medium.

Abstract: A transmitting circuit, a transceiver, a communication system, and a method for transmitting data. The transmitting circuit includes a digital interface circuit configured to obtain, in a predetermined bandwidth, data to be sent, and decompose the data into N parallel sub digital signal flows; a digital modulation circuit configured to modulate the N sub digital signal flows to obtain N modulated signals; a frequency relocation circuit configured to perform frequency relocation on the N modulated signals; a synthesizer configured to modulate M modulated signals of the N modulated signals that have undergone frequency relocation into a bandwidth signal; a digital to analog converter configured to receive the bandwidth signal, and perform digital to analog conversion on the bandwidth signal to obtain an analog signal; an up-conversion circuit configured to receive the analog signal, and convert the analog signal into a radio frequency signal.

Abstract: Transmission output detectors extract transmission outputs of a plurality of transmission branches, and an inter-branch error detector detects a combined signal level of the transmission outputs of the transmission branches to obtain an error detection signal. A correction controller calculates an amplitude error between the transmission branches based on an error detection signal, and calculates a phase error between the transmission branches based on an error detection signal which is obtained by changing the phases of the transmission branches. A phase controller and an amplitude controller correct the amplitude error and the phase error.

Abstract: A method and an apparatus for transmitting broadcast signals thereof are disclosed. The apparatus for transmitting broadcast signals comprises an encoder encoding service data, a time interleaver interleaving the encoded service data, a mapper mapping the interleaved service data into a plurality of OFDM (Orthogonal Frequency Division Multiplex) symbols to build at least one signal frame, a frequency interleaver frequency interleaving data in the at least one signal frame by using a different interleaving-seed which is used for every OFDM symbol pair comprised of two sequential OFDM symbols, wherein the frequency interleaving is performed by using two memories, a modulator modulating the frequency interleaved data by an OFDM scheme and a transmitter transmitting the broadcast signals having the modulated data, wherein an interleaving-seed is generated based on a cyclic shift value and an FFT size of the modulating.

Abstract: The disclosure generally relates to a method and apparatus for frequency interleaving. Specifically, an embodiment of the disclosure relates to a communication system having one or more antennas, a radio, a memory circuit, and a processor circuit. The antennas can be used to communicate signals or to comply with different transmission protocols. The radio can be configured to send and receive radio signals. The memory can communicate with the processor circuit and contain instructions for the processor circuit to write data carriers along a plurality of rows and columns of a 2-D store in bit-reversed order and read the columns of 2-D store.

Abstract: A device for transmitting and receiving multi-input multi-output (MIMO) signal in a wireless communication system in which a plurality of communication systems is present includes a plurality of antenna modules and a recognition module for recognizing at least one of network information or antenna information of a source device. The recognition module compares a measurement result of the plurality of antenna modules with pre-stored information to recognize the network information or antenna information of the source device.

Abstract: Systems and methods for transmitting and receiving additional data, such as video data, over legacy satellite digital audio radio signals are provided. In exemplary embodiments, hierarchical modulation can be used to transmit secondary information over a legacy signal. For example, the Sirius Satellite Digital Audio Radio Service (“SDARS”) system may use a second layer of modulation to transmit video data on top of its regular audio signal. In order to support such future services within the original system design, sometimes referred to herein as a “legacy” system, additional information bandwidth can be acquired, for example, by using hierarchical modulation to overlay data for such new services on top of the legacy transmission. In such a system, for example, overlay data can be transmitted by applying a programmable angular offset to legacy QPSK symbols, for forming a new constellation similar to 8PSK.

Abstract: An exemplary apparatus includes a modulator configured to modulate a data signal onto a carrier signal to generate a modulated signal having a transmit frequency within a predefined frequency range adjacent to and within a boundary of an uplink frequency band, a filter configured to at least partially remove a carrier frequency component from the modulated signal to produce a filtered modulated signal, and an antenna configured to transmit the filtered modulated signal.

Abstract: A modulator and a method are disclosed. The modulator is for generating a band pass signal and comprises: sigma delta modulation logic operable to receive an input signal and to perform at least a 3-level quantisation of the input signal to generate an at least 3-level quantised signal; and requantisation logic operable to requantise the at least 3-level quantised signal to a 2-level quantised signal to be provided as the band pass signal. This approach improves the coding efficiency achieved compared to that possible using a 2-level sigma delta modulator, whilst also providing improved noise performance due to the inherent linearity of the 2-level quantised signal which is provided to drive the switch mode power amplifier. Accordingly, the performance of the modulator is improved by increasing its coding efficiency whilst maintaining its linearity which improves the noise performance in adjacent channels.

Abstract: Systems and methods for training, or calibrating, a model of a frequency response of a transmitter and/or a model of a frequency response of a transmit observation receiver coupled to an output of the transmitter are disclosed. In one embodiment, in order to train a model of the frequency response of the transmitter and/or a model of the frequency response of the transmit observation receiver, a nonlinear component is connected between an output of the transmitter and an input of the transmit observation receiver. A combined model for the frequency response of the transmitter, a nonlinear characteristic of the nonlinear component, and the frequency response of the transmit observation receiver is then trained. Preferably, once the combined model is trained, the nonlinear component is disconnected for normal operation of the transmitter and the transmit observation receiver.

Abstract: Integrated circuits with wireless communications circuitry having digital predistortion (DPD) circuitry are provided. The digital predistortion circuitry may include a forward path filter, a time domain alignment (TDA) circuit, a frequency domain alignment (FDA) circuit, and an adaption circuit. The TDA circuit may receive power amplifier input signals and power amplifier output signals and may include a cross correlator, a peak detector, and a delay circuit for performing coarse time domain alignment (i.e., to align the power amplifier input and output signals). The FDA circuit may include a fast Fourier transform circuit, a matrix multiplier, and a matrix inverter for performing frequency domain alignment. The adaption circuit may analyze the aligned signals output from the FDA circuit to produce impulse response coefficients that are then used to control the forward path filter. The forward path filter may serve to predistort transmit signals prior to radio-frequency amplification.

Abstract: Multiplier coefficients are updated according to minimal power value of mixed signals in a wireless communication system. While using updated multiplier parameters, signal imbalance caused by a local oscillator or mismatch between analog elements of the wireless communication system can be reduced, so that the wireless communication system can be immune from noises.

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: 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: System and method embodiments are provided for high efficiency wireless communications. In an embodiment, a method in a network component for transmitting a frame of two different fast Fourier transform (FFT) sizes includes generating a frame, wherein the frame comprises orthogonal frequency-division multiplexing (OFDM) symbols in two different FFT sizes, wherein the frame comprises a first portion and a second portion, wherein the first portion comprises a first FFT size and the second portion comprises a second FFT size; and transmitting the frame during a single transmission opportunity.

Abstract: A method and an apparatus for sending signals to suppress outband interference effectively in a simple way includes: grouping subcarriers in a spectrum into edge subcarriers of the spectrum and non-edge subcarriers of the spectrum; precoding data to be sent to obtain modulated symbols of the data on the subcarriers, where the precoding makes every two adjacent edge subcarriers of the spectrum in the edge subcarriers of the spectrum carry a pair of modulated symbols with opposite polarities, and makes each of the non-edge subcarriers of the spectrum carry a modulated symbol with no polarity; and sending the modulated symbols of the data on the subcarriers. The embodiments of the present invention are applicable to a signal sending process.

Abstract: A communication apparatus according to the present invention comprises first communication means configured to transmit differential signals serving as first information over a first wire pair; second communication means configured to transmit differential signals serving as second information over a second wire pair; and third communication means configured to transmit third information by transmitting one of differential signals over the first wire pair and transmitting the other of the differential signals over the second wire pair. It is possible to provide a communication apparatus that spurious emission is suppressed.

Abstract: A transmission device 100 has an inverse fast Fourier transform converter 104 (first circuit) that acquires plural multi-value symbol data each of which is assigned to a dedicated subcarrier, and generates waveform data on the basis of the acquired plural multi-value symbol data, and a digital frequency converter 107 (second circuit) that shifts frequency of the waveform data generated by the inverse fast Fourier transform converter 104.

Abstract: In various embodiments, a computer-implemented method for optimized data transfer utilizing optimized code table signaling is disclosed. In one embodiment, a computer-implemented method comprises receiving, by a processor, a digital bit stream and transforming, by the processor, the digital bit stream to an encoded digital bit stream. The encoded digital bit stream comprises at least one of a gateway channel, a composite channel, or a data channel, and any combination thereof. The computer-implemented method further comprises providing, by the processor, the encoded digital bit stream to a transmission system for transmission and establishing, by the processor, signal integrity by utilizing pre-coordinated, pre-distributed information to limit the transmission to an intended sender-receiver pair. The intended sender-receiver pair comprises the pre-coordinated, pre-distributed information.

Abstract: A communication level table storage unit stores a communication level table that defines correspondence between a communication level at least defined by MCS (modulation scheme and coding rate) and a range of required CINR at the communication level. A communication quality management unit obtains CINR of a received signal at another communication apparatus which is a communication partner. A setting unit refers to the communication level table, and when a difference between a representative value of a range of required CINR at a current communication level and a representative value of a range of required CINR of CINR at a communication level which is one level higher is more than or equal to a threshold value, sets a communication level such that the obtained CINR of the received signal is included in the range of required CINR.

Abstract: A duty-cycle modulated bit signalling method and circuit, comprising: signaling bits by virtue of a duty-cycle ratio; wherein the duty-cycle ratio is varied dependent upon the transmission rate of the signalling. A bit period comprises a long phase and a short phase and the duty-cycle therebetween is varied such that the ratio between the duration of the long phase and the duration of the short phase is increased for decreasing transmission rate. The duty-cycle ratio is varied dependent upon the transmission rate of the signalling according to one or more ranges of transmission rate. In a higher transmission rate range the duty-cycle is defined as a fixed ratio, and in a lower transmission range the duty-cycle is defined by a fixed length of the short phase of the bit period.

Abstract: Embodiments of a circuit are described. In this circuit, a modulation circuit provides a first modulated electrical signal and a second modulated electrical signal, where a given modulated electrical signal, which can be either the first modulated electrical signal or the second modulated electrical signal, includes minimum-shift keying (MSK) modulated data. Moreover, a first phase-adjustment element, which is coupled to the modulation circuit, sets a relative phase between the first modulated electrical signal and the second modulated electrical signal based on a phase value of the first phase-adjustment element. Additionally, an output interface, which is coupled to the first phase-adjustment element, is coupled to one or more antenna elements which output signals. These signals include a quadrature phase-shift-keying (QPSK) signal corresponding to the first modulated electrical signal and the second modulated electrical signal.

Abstract: A multi-port information communication system includes a reference clock signal generator configured to generate a reference clock signal. The system also includes a phase controller configured to generate a plurality of information communication clock signals based on the reference clock signal by staggering a phase of each of the information communication clock signals. The phase controller includes a delay-locked loop configured to generate a plurality of delay-locked loop signals based on the reference clock signal, and a plurality of time delay elements. Each time delay element is configured to produce a respective one of the information communication clock signals by adding a respective delay to a respective one of the delay-locked loop signals. The system includes information communication devices each including a respective transmitter. Each of the transmitters is configured to operate in response to a respective one of the information communication clock signals.

Abstract: Disclosed herein is a method of generating an uplink reference signal in a system supporting a plurality of uplink access schemes. The method includes, at a base station, transmitting reference signal configuration information indicating the configuration of a reference signal to be transmitted in uplink, which is generated according to the plurality of uplink access schemes, to a user equipment which is set to operate in an uplink access scheme corresponding to the information, and receiving a subframe including the reference signal generated based on the reference signal configuration information from the user equipment. The reference signal configuration information includes a cyclic shift value of a sequence of the reference signal.

Abstract: A receiver performs interference mitigation under blind or semi-blind conditions using diversity present in the signal of interest or in the interferer. A first path interference mitigation procedure extracts training information from received signals, performs interference mitigation on the training information and estimates the channel. The second path interference mitigation procedure uses data extracted from the received signal and the channel estimate to perform interference mitigation. Each interference mitigation process can take the form of a lossy compression followed by decompression.

Abstract: A non-display signal encoding method cooperates with a matrix substrate including a plurality of electrodes. The electrodes cross each other and transmit a plurality of display signals and a plurality of non-display signals. The non-display signal encoding method comprises steps of: transmitting the non-display signals by at least one of the electrodes during a first time; and receiving by coupling at least a part of the non-display signals by at least an external object, wherein the non-display signals have at least three states, i.e. a first state, a second state, a third state or their any combination, and the first, second and third states are different from one another. A matrix substrate is also disclosed.

Abstract: When signals to be transmitted to a plurality of mobile station devices are multiplexed by hierarchical modulation in a downlink, an increase in difference in reception quality among the mobile station devices is prevented. A transmitting device of the present invention is a transmitting device which performs data transmission to a plurality of receiving devices by using a plurality of symbols and a plurality of layers with different distances between signal points, and includes a modulating unit 118-n which assigns data to be transmitted to a first receiving device to a first layer in a predetermined symbol of the plurality of symbols and assigns data to be transmitted to a second receiving device different from the first receiving device to the first layer in remaining symbols and a transmission processing unit 127 which transmits each data assigned to the first layer to the first receiving device and the second receiving device.

Abstract: A transmitter incorporates a table (TBL1) for assigning the frame lengths of 560 ?s and 600 ?s to the code “0” in a binary system and assigning the frame lengths of 600 ?s and 560 ?s to the code “1” in the binary system. The transmitter refers to the table (TBL1) and assigns the two frame lengths of 560 ?s and 600 ?s and the two frame lengths of 600 ?s and 560 ?s to the codes “0” and “1”, respectively, in the code sequences [0,0], [0,1], [1,0] and [1,1] representing the transmission information “0” to “3” represented using the binary system, and sequentially transmits four radio signals having the assigned four frame lengths.

Abstract: Disclosed is a method for generating and transmitting a reference signal in a clustered DFT-spread OFDM transmission scheme. A method for generating and transmitting a DM-RS in a clustered DFT-spread-OFDM scheme comprises: a step of generating DM-RS sequences corresponding to the number of clusters allocated for an uplink transmission; and a step of mapping the generated DM-RS sequences to the relevant DM-RS symbol positions for each cluster. Accordingly, the method for generating and transmitting a reference signal according to the present invention, in which DM-RS sequences are allocated and transmitted on a cluster basis, uses a complete DM-RS sequence for each cluster, and therefore inter-cell interference can be weakened, and problems which might occur when applied to a multi-user MIMO (MU-MIMO) scheme can be solved.

Abstract: A method and apparatus are disclosed comprising a combined open loop/closed loop uplink power control scheme for E-UTRA. The combined open and closed loop method for UL intra-cell PC controls the wireless transmit receive unit (WTRU) transmit power spectral density (PSD), PSDTx, (e.g. power per RB).

Abstract: For use in a transmitter in a wireless network, a transmitter apparatus is configured for digital multi-level outphasing. The apparatus includes a bandwidth reduction (BWR) modulator block configured to receive a phase modulated carrier and reduce a bandwidth of the phase modulated carrier using amplitude modulation. The apparatus also includes an outphasing modulator block configured to receive the reduced-bandwidth phase modulated carrier and an amplitude modulated signal, and convert the reduced-bandwidth phase modulated carrier into a plurality of phase modulated signals. The apparatus further includes an amplification stage comprising a plurality of power transistors configured to amplify the phase modulated signals.

Abstract: The present invention provides, in one embodiment, a method of transmitting a message. The method includes transmitting a first codeword from a transmitter to a relay. The method also includes subsequently transmitting a second codeword based on the first codeword from the relay and a third codeword from the transmitter wherein the second and third codewords are transmitted concurrently.

Abstract: Systems and methodologies are described that facilitate transmitting at least two different types of information in a single signal, whereby the different types of information can be encoded and decoded independently. Thus, changes to one type of information does not affect a second type of information.

Abstract: An apparatus for reconstructing digital video data stream reconstructs a transport stream from a first data stream and a second data stream. Both of the first data stream and the second data stream comprise a plurality of packets, a plurality of input stream time reference (ISCR) values, and a plurality of deleted null packet (DNP) values. The apparatus includes a packet interval detector, that estimates a packet interval according to the first data stream or the second data stream; an alignment unit, that generates an alignment signal according to the ISCR values and the packet interval; an oscillator, coupled to the packet interval detector, that generates an output pulse signal; and a reconstruction controller, that reconstructs the transport stream from the first data stream and the second data stream and outputs the transport stream according to the alignment signal and the output pulse signal.

Abstract: A RF digital to analog converter has a first capacitor arrangement, a first common node, and a first controller. The first capacitor arrangement has multiple switchable capacitor paths arranged in parallel. Respective switchable capacitor paths have a switchable element and a capacitor coupled in series. The first common node is connected to the multiple switchable capacitor paths. The first controller receives a baseband signal having a component, and a local oscillator (LO) signal. The first controller combines the component and the LO signal to obtain a first modulation signal. The first controller controls the multiple switchable capacitor paths of the first capacitor arrangement with the first modulation signal.

Abstract: There is provided a system that includes a tunable amplification module, a coupler, an interface module; a detector that is arranged to output an impedance indicative signal and a power indicative signal; wherein the impedance indicative signal is indicative of an impedance mismatch between an output impedance of the tunable amplification module and an impedance of a radio frequency (RF) antenna as seen by the tunable amplification module, wherein the power indicative signal is indicative of an output power of the tunable amplification module.

Abstract: An enhanced VSB receiver includes a tuner which tunes an RF signal and converts it into an IF signal, an IF mixer which converts the IF signal into a baseband signal, and a demodulator which demodulates the baseband signal into a VSB signal. The enhanced VSB receiver further includes a map recovery unit which recovers VSB map information of the VSB signal, an enhanced equalizer for compensating channel distortion of the VSB signal and outputting an equalized symbol, and an enhanced Viterbi decoder for estimating whether polarity inversion occurred during a symbol period of the equalized symbol and Viterbi-decoding the equalized symbol based on the polarity estimation.

Abstract: The present invention relates to receiving control information in an orthogonal frequency division multiplexing (OFDM) system of a mobile communication system. The present invention includes receiving information related to a number of OFDM symbols in a subframe for receiving first control information, receiving information related to a number of OFDM symbols in the subframe for receiving second control information, decoding the first control information according to the received information related to the number of OFDM symbols in the subframe for receiving the first control information, and decoding the second control information according to the received information related to the number of OFDM symbols in the subframe for receiving the second control information, wherein the number of OFDM symbols for receiving the first control information is less than or equal to the number of OFDM symbols for receiving the second control information.