摘要:
A method and a system for transmitting data by a transmitter over a channel having a predetermined channel quality estimate, comprises the steps of splitting (S2P) input data stream (S40, S60, S80) to be transmitted into a plurality of data sub-streams (S40a, S40b, S40c); processing (SYM1, SYM2, SYMj) each of the plurality of data sub-streams (S40a, S40b, S40c) into a plurality of symbol subsets (S41, S42, S43) by selecting a certain scheme of coded-modulation (BPSK, QPSK, 16-QAM); processing, separately, each of the plurality of symbol subsets (S41, S42, S43), via a plurality of separate Discrete Fourier Transforms (DFT1, DFT2, DFT3), herein after denoted as DFTs, to obtain a plurality of DFT-precoded data sub-streams (S44, S45, S46); allocating each DFT-precoded data sub-stream (S44, S45, S46) in a frequency resource block (RB1, RB2, RB3), via a sub-carrier mapping module (SCM), so that for each data sub-stream (S40a, S40b, S40c) the selected scheme of coded-modulation (BPSK, QPSK, 16-QAM) is chosen in dependence of the values of the channel quality estimate at the frequencies of its own allocated frequency resource block (RB1, RB2, RB3).
摘要:
Prior to transferring to a radio communication system, at least one data block is encoded according to predetermined quality-of-service requirements with the aid of a first code. Subsequently, the data block, encoded by the first code, is further encoded according to the radio transmission properties of a usable radio transmission source with the aid of a second code.
摘要:
In an OFDM multi carrier modulation method, M sub-carriers are used in a frequency band of a broadband mobile radio channel and several symbols are used in a time band. With application of a MIMO multi-antenna method with T transmitting antennae and R receiving antennae, for all sub-carriers and all symbols, a single, pre-determined, channel-matched transmission strategy is used, which is described by a maximum of T*R complex values on the signal side, independent of the species of the MIMO multi-antenna method and independent of the size of the frequency/time bands.
摘要:
In a communication system, a first transmitting station transmits a transmission signal to a first receiving station for transmitting a sequence of data via a radio interface. The radio interface is monitored with respect to an interference signal from an interference source prior to transmission via at least one of the first transmitting station and the first receiving station. The transmission only begins if the radio interface is sufficiently free from interference for a moment in time.
摘要:
A method performs synchronization in an at least partly self-organizing radio communication system with a number of mobile stations which lie across an air interface within two-way radio range. At least some mobile stations from the number of mobile stations transmit synchronization sequences, by which a part or all the mobile stations of the number of mobile stations synchronize.
摘要:
The invention relates to a method for switching a communications link to another channel (handover) in a digital cellular mobile radio systems and a mobile radio system, the time of the handover being determined by a decision algorithm. Roughly generalized, the changeover to a new channel can take place between two radio systems or frequency bands within a radio system (external handover), between two radio cells within a cellular network (intercell handover) or within a radio cell (intracell handover). Each handover case, in turn, can include various type of handover.
摘要:
In a radio system having stations which are at least partially provided with a directional antenna, a first emitting station is provided with a directional antenna in a first spatial radio area. The first emitting station sends a direction information message indicating the spatial direction in which the data is to be transmitted. Transmission resources can be advantageously occupied based on the direction information message.
摘要:
A method performs synchronization in an at least partly self-organizing radio communication system with a number of mobile stations which lie across an air interface within two-way radio range. Al least some mobile stations from the number of mobile stations transmit synchronization sequences, by which a part or all the mobile stations of the number of mobile stations synchronize.
摘要:
Irregular LDPC codes have a construction which allows one to obtain a number of codes with different length from a single prototype code with a parity check matrix given by H=[Hz Hi], where Hz specifies the well-known zigzag pattern in the corresponding Tanner graph. The parity check matrices for longer codes are obtained as [Hz′Πdiag(Hi, . . . , Hi)], where Hz′ specifies a longer zigzag pattern depending on the number of matrices Hi used, and Π represents some permutation. This allows one to construct the decoder for a longer code by reusing hardware components developed for decoding the prototype code.
摘要:
A method transmits data by radio during which a frequency band is split into a plurality of subcarriers, and a plurality of antennas are used for transmitting. The data are split into a number of elements, which are to be respectively transmitted by each antenna, said number of elements corresponding to the number of subcarriers, whereby for each antenna, each element is respectively assigned to a subcarrier for transmitting, and at least two antennas on at least one subcarrier transmit different elements. Before an OFDM modulation for each antenna, each element is multiplied by an antenna-specific and element-specific factor. Alternatively, after an OFDM modulation for at least one antenna, the time sequence of the time-dependent signal generated on the basis of the OFDM modulation is reordered. A transmitter carries out the method.