907results about "Transmitter specific arrangements" patented technology

The invention relates to methods for providing a network element 5 of a communications network with data, in particular HSDPA related data. In order to enable the transmission of user data, it is proposed that a controller 4 of the network uses a dedicated frame structure for assembling frames with said user data. The frames can then be transmitted from the controller 4 via an interface to the network element 5. In order to enable the transmission of control parameters, it is further proposed that an interface application protocol is employed which allows the controller 4 to add control parameters to control messages transmitted from the controller 4 to a network element 5 via the interface.

A method of transmitting data in a wireless communication system comprises receiving feedback data on an uplink data channel, the feedback data comprising a precoding matrix indicator (PMI), wherein the value of the PMI corresponds to an index in a codebook, transmitting a precoding scheme for downlink data on a downlink control channel, wherein the preceding scheme is determined as one of at least two of a transmit diversity irrespective of the received PMI, an acknowledgement indicating preceding according to the received PMI and a new PMI indicating that it is used in precoding downlink data to be transmitted, and transmitting the downlink data on a downlink data channel after applying precoding according to the determined preceding scheme.

A method of transmitting a sounding reference signal includes generating a physical uplink control channel (PUCCH) carrying uplink control information on a subframe, the subframe comprising a plurality of SC-FDMA(single carrier-frequency division multiple access) symbols, wherein the uplink control information is punctured on one SC-FDMA symbol in the subframe, and transmitting simultaneously the uplink control information on the PUCCH and a sounding reference signal on the punctured SC-FDMA symbol. The uplink control information and the sounding reference signal can be simultaneously transmitted without affecting a single carrier characteristic.

A multi-carrier communication system such as an OFDM or DMT system has nodes which are allowed to dynamically change their receive and transmit symbol rates, and the number of carriers within their signals. Changing of the symbol rate is done by changing the clocking frequency of the nodes' iFFT and FFT processors, as well as their serializers and deserializers. The nodes have several ways of dynamically changing the number of carriers used. The selection of symbol rate and number of carriers can be optimized for a given channel based on explicit channel measurements, a priori knowledge of the channel, or past experience. Provision is made for accommodating legacy nodes that may have constraints in symbol rate or the number of carriers they can support. The receiver can determine the correct symbol rate and number of carriers through a priori knowledge, a first exchange of packets in a base mode that all nodes can understand, or an indication in the header of the data packet which is transmitted in a base mode of operation that all nodes can understand.

According to embodiments of the invention, a communications system includes an error correction encoder that error correction encodes a bitstream according to an error correction code. The system also includes a variable symbol generator that generates a symbol according to a selected one of a plurality of selectable signal constellations from a group of bits of the error correction encoded bitstream. The system further includes a spreader that spreads the symbol according to a spreading code, and a transmitter that transmits the spread symbol in a communications medium. Preferably, the plurality of selectable signal constellations includes at least two signal constellations of different order. In other embodiments, the error correction encoder includes a variable error-correction encoder that encodes the bitstream according to a selected error correction code of a plurality of selectable error correction codes. In still other embodiments, the spreader includes a variable spreader that spreads the symbol according to a selected spreading code of a plurality of selectable orthogonal spreading codes including at least two spreading codes of different lengths. A controller may select the error correction code used by the variable error correction encoder, the signal constellation used by the variable symbol generator, and the spreading code used by the variable spreader to provide a desired information transmission rate for the bitstream. Related methods are also described.

A base station selects and assigns uplink segments to specific wireless terminals. The base station estimates potential system interference levels, selects, assigns, and transmits a maximum uplink rate indicator value to a wireless terminal indicating the maximum uplink data rate that the wireless terminal is permitted to use. The wireless terminal receives the maximum data rate indicator and selects an uplink data rate to use which is less than or equal to the maximum data rate indicator level. The selection includes consideration of data amounts, data importance, communications channel quality, changes affecting the channel and / or power information. The wireless terminal encodes information indicative of the selected used rate with the user data / information to be transmitted by placing additional energy on a subset of the uplink signals. The base station receives the uplink signals including user data / information and data rate. The base station extracts the data rate used and utilizes the data rate to demodulate and decode the uplink user data / information.

A base station has a time correlation calculating unit for estimating a variation-with-time characteristic of radio link quality using radio downlink quality information reported by a mobile station, a target error rate setting unit for changing over a target error rate adaptively using this variation-with-time characteristic, and an MCS decision unit for deciding a modulation scheme and / or encoding rate, in such a manner that packet error rate becomes equal to the target error rate, using the radio link quality information as well as reception success / failure information reported by the mobile station. The base station transmits a packet based upon the modulation scheme and / or encoding rate decided.

An average signal point amplitude detection section 15A determines an average position of I and Q components when a received QPSK modulated signal is demodulated and a threshold calculation section 15B determines threshold ths on an IQ plane based on the average signal point position of the received QPSK modulated signal and a theoretical distribution position on the IQ plane of signal points of a 16-value QAM signal. Then, a threshold decision section 14A makes a threshold-decision on the I and Q components of sequentially received QPSK modulated signals using this threshold ths and thereby calculates a simulated bit error rate of the 16-value QAM signal.

A method and apparatus for providing a link quality report in a wireless communication system supporting link adaptation. An input signal carrying data blocks in one or several transmission intervals of a reporting interval is received by a receiver of the apparatus. A quality measurement unit provides a link quality measure of the current reporting interval. A correction unit corrects the link quality measure by determining a SIR loss of the link, which is induced by unmatched transmission parameter settings of a physical layer. Then, a link quality report for the current reporting interval is based on the corrected link quality measure and transmitted by the transmitter to the transmitting unit, which will adapt the setting of physical layer parameters accordingly.

A method and medium tangibly embodying the method of constructing a lookup table of modes for encoding data for transmission in a wireless communication channel from a transmit unit to a receive unit by using at least one quality parameter of the data and its first-order and second-order statistical parameters to arrange the modes in the lookup table. The first-order and second-order statistical parameters can be determined from a simulation of the wireless communication channel or from field measurements of the wireless communication channel. The modes in the lookup table are ordered by a target value of a communication parameter such as PER, BER, data capacity, signal quality, spectral efficiency, throughput or another suitable communication parameter set to achieve a desired quality of service. The quality parameter selected is conveniently a short-term quality parameter such as signal-to-interference and noise ratio (SINR), signal-to-noise ratio (SNR) or power level. During use adjustments depending on the instantaneous condition of the channel can be used to tune the lookup table.

The present invention includes a method of optimizing a transmission mode of wirelessly transmitted data. The method includes selecting a first transmission mode based on a predetermined channel database and a first channel characterization. The first channel characterization can be based upon signals transmitted in an initial mode. An error factor is generated based on a difference between an estimated performance characteristic, and an expected performance characteristic. A subsequent transmission mode is selected based upon the predetermined channel database, the error factor and a subsequent channel characterization. The predetermined channel database can include a predetermined look-up-table that provides transmission mode selections based upon the channel characterizations. The look-up-table generally includes a plurality of quality parameter thresholds that determine the selection of a transmission mode. Another method includes receiving transmission signals that include data encoded in an initial transmission mode. A first quality parameter of the received transmission signals is measured. A subsequent transmission mode is selected based upon the quality parameter. Transmission signals are received having data encoded in the subsequent transmission mode. A second quality parameter is measured. A parameter is adjusted within selection criteria of another subsequent transmission mode based upon the second quality parameter.

The present invention is directed to a digital broadcast system and a data processing method. A broadcast signal in which mobile service data and main service data are multiplexed is transmitted and received. Then, in a broadcasting receiver, the program table information including information about a service or a program of an ensemble is parsed according to an identifier of the ensemble in which the mobile service data are multiplexed, in the received broadcast signal. And a mobile service is outputted by using the mobile service data and the parsed program table information.

A mobile communication system that is a wireless communication system using the AMC scheme and does not require any transmission / reception of control signals between a base station apparatus and a mobile station apparatus during controlling of the transmission / reception of the mobile station apparatus. In this mobile communication system, the mobile station apparatus measures reception quality of a downlink signal transmitted by the base station apparatus, and uses an uplink control channel to transmit, to the base station apparatus, downlink signal quality information (CQI) corresponding to the measured reception quality. The base station apparatus receives the downlink signal quality information CQI to control the data transmission to the mobile station apparatus. The base station apparatus judges whether the downlink signal quality information CQI transmitted by the mobile station apparatus is present, and controls, based on the result of this judgment, the downlink signal to be transmitted to the mobile station apparatus.

A method for transmitting a packet of N input bits includes encoding all of the N bits as a single entity, such as with an interleaver of length N within a turbo coder, outputting M encoded bits, channel interleaving the M bits, splitting the M encoded bits into a parallel first and second portion, and transmitting them over separate channels to achieve spatial diversity. The size of the first and second portion is determined based on a closed feedback loop that provides some knowledge of the channel, preferably a measure of channel capacity. The feedback loop may also provide channel knowledge to a subpacket selector associated with each transmit antenna, which determines an appropriate rate for that channel and selects subpackets to fill a transmission packet for that channel. The subpacket selectors choose a subpacket of systematic bits and fill the remaining transmission packet size with subpackets of parity bits. Eigenvectors may be employed to transmit each transmission packet over more than one channel with a power disparity between the channels. A transmitter according to the present invention is also described.

An SIR information extracting section 106 extracts SIR measured at a communication terminal from the received data, and a fluctuation amount calculating section 109 calculates a fluctuation amount of SIR between time at which the communication terminal has measured SIR and transmission starting time of DSCH data using a TPC command, and a. transmission system determining section 110 adds the SIR fluctuation amount calculated in the fluctuation amount calculating section 109 to the SIR measured at the communication terminal and estimates SIR of DSCH data so as to determine an optimal transmission system of DSCH data according to the estimated SIR.

A subcarrier transmission ON / OFF control system based on an MC-CDMA system capable of improving information transmission efficiency and reception performance while keeping the number of transmission bits constant. Furthermore, a subcarrier transmit power control system based on an MC-CDMA system or OFDM system capable of improving information transmission efficiency and reception performance. The former system based on the MC-CDMA system does not carry out transmission through subcarriers of low reception quality, with no transmit power assigned (transmission OFF), assigns the corresponding transmit power to subcarriers with transmit power assigned (transmission ON) and carries out transmission (subcarrier transmission ON / OFF control) The latter system based on the MC-CDMA system or OFDM system carries out transmission according to a reception level of each subcarrier on the receiving side, with greater transmit power assigned to subcarriers with higher reception levels and smaller transmit power assigned to subcarriers with lower reception levels (subcarrier reverse transmit power control).

A communication system and method includes the steps of: a) transmitting an ACK signal indicating a received packet includes no error or a NACK signal indicating the received packet includes error from a reception end to a transmission end, and performing automatic repeat request; b) obtaining reliability of the received packet when demodulating it at the reception end; and c) reporting from the reception end to the transmission end the reliability of the received packet utilizing the ACK / NACK signal by using not less than three levels.

A method of transmitting feedback data in a multiple antenna system includes generating feedback data based on the channel information and transmitting the feedback data at transmission periods, wherein the feedback data is transmitted in a plurality of report types respectively having a different control signal type contained depending on the transmission periods.

A mobile communication system is provided which is capable of preventing a reduction in user throughput and system throughput. In a radio base station, a dataflow control unit controls an Iub dataflow from an RNC, a buffer stores the dataflow for each terminal in each corresponding queue, and a scheduler schedules the dataflow. An HARQ control unit controls retransmission of the dataflow and corrects CQI report values received from a terminal at a corrector. An encoding processor encodes the dataflow, and a demodulator demodulates data received from the terminal. After the demodulation of the data received from the terminal, the demodulator sends CQI information and Ack / Nack information to the HARQ control unit. The corrector in the HARQ control unit then corrects the CQI report value in accordance with these received CQI information and Ack / Nack information.

A method of controlling link adaptation and packet scheduling in an HSDPA (High Speed Downlink Packet Access) radio system and an HSDPA base station communicating over a control channel with one or more user equipment units is provided. According to one embodiment the base station includes a device for receiving feedback information from the user equipment. The base station further includes a device for calculating a quality estimate related to the feedback information and executing link adaptation and packet scheduling based on the calculated quality estimate.

The embodiment of the invention provides a transmission method for feedback information, which comprises the following steps that: a base station sets control signaling VDAIDL for downlink control information carried by user equipment (UE) in physical downlink control channels (PDCCH) of all scheduling physical downlink share channels (PDSCH) or / and PDCCHs indicating semi-persistent scheduling (SPS) resource release in a feedback window, allocates a control information modulation and coding scheme (MCS) offset value beta offset HARQ-ACK to the UE in a semi-static state and informs the UE of the offset value through high-level signaling; and the base station receives acknowledgement / negative acknowledgement (ACK / NACK) feedback information sent by the UE through a physical uplink share channel (PUSCH) according to VDAIDL and the beta offset HARQ-ACK and performing corresponding processing. According to the scheme provided by the invention, a method for ACK / NACK multiplexing of a long term evolution time division duplex (LTE TDD) system can be expanded, so that the method for the feedback information can be applied to LTE / LTE-A, and the problem of multiple ACK / NACK feedbacks caused by carrier aggregation can be solved simultaneously. In addition, in the scheme provided by the invention, the change of the conventional system is small, the compatibility of the system cannot be influenced, and the scheme is simply and efficiently realized.

A method and communication system for selecting a mode for encoding data for transmission in a wireless communication channel between a transmit unit and a receive unit. The data is initially transmitted in an initial mode and the selection of the subsequent mode is based on a selection of first-order and second-order statistical parameters of short-term and long-term quality parameters. Suitable short-term quality parameters include signal-to-interference and noise ratio (SINR), signal-to-noise ratio (SNR), power level and suitable long-term quality parameters include error rates such as bit error rate (BER) and packet error rate (PER). The method of the invention can be employed in Multiple Input Multiple Output (MIMO), Multiple Input Single Output (MISO), Single Input Single Output (SISO) and Single Input Multiple Output (SIMO) communication systems to make subsequent mode selection faster and more efficient. Furthermore the method can be used in communication systems employing various transmission protocols including OFDMA, FDMA, CDMA, TDMA.

A communication system performs adaptive scheduling by considering present and past reported CQI values and other indications of channel conditions in scheduling a Modulation and Coding Scheme (MCS) and then executing a ‘dithering’ function in order to effectuate an MCS that is intermediate between adjacent discrete MCSs. In one embodiment, the communication system determines a first MCS based on a channel quality metric received from a mobile station (MS) and then transmits data utilizing the first MCS. The communication system assigns weights to each of the first MCS and a second MCS based on whether the transmitted data is acknowledged and, based on the assigned weights, selects one of the first and second MCSs for a subsequent transmission of data to the MS. The communication system also may assign weights to each of a first and second MCS based on a transition between a MIMO-A and a MIMO-B transmission scheme.

A system controls operation of a network, such as a WLAN, where at least one information stream is delivered to at least one user via a link that is exposed to variable operating conditions. The system includes a controller module for monitoring the operating conditions of the link, and at least one transcoder for selectively transcoding the information stream by selectively varying one or more transcoding parameters as a function of the monitored operating conditions.

An adaptive subchannel and bit allocation method in a wireless communication system. A mobile station analyzes channel quality information of a subchannel at a predetermined period and determines a feedback band index with a maximum decision criterion. The mobile station feeds back the determined feedback band index with the maximum decision criterion to a base station. The base station generates band allocation information using the feedback information from the mobile station, and transmits the band allocation information to the mobile station. The mobile station transmits AMC information using the band allocation information received from the base station. The base station estimates a channel using the AMC information transmitted from the mobile station and allocates bits to the allocated band according to the channel estimation result.

Systems and methods for transporting data between two endpoints over an encoded channel are disclosed. Data transmission units (data units) from the source network are received at an encoding component logically located between the endpoints. These first data units are subdivided into second data units and are transmitted to the destination network over the transport network. Also transmitted are encoded or extra second data units that allow the original first data units to be recreated even if some of the second data units are lost. These encoded second data units may be merely copies of the second data units transmitted, parity second data units, or second data units which have been encoded using erasure correcting coding. At the receiving endpoint, the second data units are received and are used to recreate the original first data units.

Methods and apparatus for optimum file transfers in a time-varying network environment. A method is provided for transmitting content in a data network. The method includes transmitting content at a selected transmission rate, and receiving one or more acknowledgement signals. The method also includes estimating a network delivery rate from the one or more acknowledgment signals, and adjusting the selected transmission rate of the content based on the network delivery rate.