311results about "Unequal error protection" patented technology

A hybrid ARQ scheme is used incremental data packet combining. In an example embodiment, the hybrid ARQ scheme with incremental data packet combining employs three feedback signaling commands: ACK, NACK, and LOST. Using these three feedback commands, the hybrid ARQ scheme with incremental data packet combining provides both robustness and good performance. This scheme is particularly advantageous in communication systems with unreliable communication channels, e.g., a fading radio channel, where forward error correction (FEC) codes are used and some of the code symbols are more important than other code symbols. Benefits include increased throughput and decreased delay of the packet data communication.

A method for transmitting common control information from a base station to a plurality of subscriber stations in a wireless communication. The common control information includes first information transmitted in common to all of the subscriber stations and second information separately transmitted to the subscriber stations according to channel states of the subscriber stations. The first information is transmitted using an MCS (Modulation and Coding Scheme) level having a modulation scheme with a lowest order and a coding scheme with a lowest coding rate among all MCS levels available in the base station. The second information is transmitted using MCS levels that are adjusted by a predetermined level against MCS levels corresponding to channel states of the subscriber stations.

A digital broadcast transmitting / receiving system and a method for processing data are disclosed. The method for processing data may enhance the receiving performance of the receiving system by performing additional coding and multiplexing processes on the traffic information data and transmitting the processed data. Thus, robustness is provided to the traffic information data, thereby enabling the data to respond strongly against the channel environment which is always under constant and vast change.

A packet transmission method for transmitting packets classified according to a quality of service (QoS) requirement from a transmitting node to a receiving node is provided. In the transmitting node, the steps of: selecting sequentially a QoS class; dividing a queued packet to be transmitted belonging to the selected class into a plurality of predetermined data units, and transmitting one of the obtained predetermined data units; and applying a transmitter-side retransmission control process to the data unit to be transmitted when the selected class is a QoS class specified for data type packets are provided. In the receiving node, the steps of: receiving sequentially the data units transmitted from the transmitting node; assembling a plurality of received data units to decompress the original packet for each QoS class; and applying a receiver-side retransmission control process to the received data units to be assembled when the received data unit belongs to one of the QoS classes specified for the data type packets are provided.

A particular protocol layer of the transmitting side (transmitter) initially receives service data units (SDUs) having the same priority through a single stream from an upper layer, processes these SDUs to generate protocol data units (PDUs) having different priorities, and uses respectively different transmission methods to transmit the generated PDUs over a radio interface in order to guarantee their respectively different quality of service (QoS) requirements.

A method and system of wireless communication is provided which involves inputting information bits, wherein certain bits have higher importance level than other bits, and applying unequal protection to the bits at different importance levels. As such, important bits are provided with more protection for transmission and error recovery. Applying unequal protection involves using skewed constellations such that more important bits are provided with more error recovery protection.

A method of mobile communication including a transmitter having multiple transmitters and a receiver having multiple receivers. The method includes adding a cyclic redundancy check (CRC) code to a data block to be transmitted and spatially segmenting the data block according to a modulation scheme and a coding rate of each respective transmit antenna of the multiple antennas.

A method and system for providing Voice over Internet Protocol (VoIP) in a wireless communications system using a Packet Data Conversion Protocol (PDCP) with enhanced functionality that allows sub-packets to be processed for transmission over different Radio Bearers (RB) with unequal or different levels of error protection and / or error detection based on perceptual importance of the bits in the sub-packets. The enhanced PDCP being operable to partition a packet into a plurality of sub-packets such that different levels of error protection and / or error detection may be applied to the packet. An overall gain in system capacity can be expected due to transmit power savings provided via unequal error detection and error protection.

A coding section 101 turbo-codes transmit data and outputs parity bit data, and systematic bit data for which good quality is required. A modulation section 102 modulates the parity bit data and systematic bit data. A subcarrier allocation section 103 rearranges the transmit data so that systematic bit data is allocated to subcarriers in the vicinity of the center frequency and parity bit data is allocated to subcarriers in the vicinity of both ends. An OFDM section 104 performs orthogonal frequency division multiplexing of the transmit data, and allocates parity bit data and systematic bit data to respective subcarriers. By this means, it is possible to improve significantly the error rate characteristics of transmit data for which good quality is required, and prevent degradation of the quality of transmit data for which good quality is required.

A DTV signal is transmitted that avoids legacy DTV receivers regarding data segments used in other than ordinary 8VSB transmissions being mistaken for (207, 187) R-S FEC codewords that appear to free of byte error or can be corrected to appear so. The DTV signal is analyzed prior to its transmission, for detecting those data segments used in other than ordinary 8VSB transmissions that legacy DTV receivers could mistake for correct (207, 187) R-S FEC codewords or correctable (207, 187) R-S FEC codewords. Twenty bytes of each segment of data that could be so mistaken are modified to prevent such mistake. Complementing certain bits in the final twenty bytes of each segment of data is preferred if data are transmitted at one-half or one-quarter ordinary 8VSB code rate. Segments of control data, each pertaining to a respective future group of said segments of data, are transmitted in a further aspect of the invention for indicating which data segments are modified. These segments of control data can further include information concerning the type of modulation used in each data segment.

A communication method, transmitter, receiver, and cellular ratio communication system. When the high priority data and the low priority data are transmitted at the same time in the multi-carrier communication, a processing in accordance with the priority is performed to decode data accurately. At the transmitting side, the high priority symbols and the low priority symbols are alternately positioned and each symbol of the differential symbol stream obtained by differential-modulating the high priority data based on the differential phase is assigned to sub-carrier. The transmission signal in which the sub-carriers on which high priority symbols are superimposed and the sub-carriers on which low priority symbols are superimposed are positioned alternately is transmitted. At the receiving side, when the transmission signal is received at a reception timing having transfer delay, the phase offset component is detected from the high priority symbol of the symbol stream obtained by performing a predetermined reception processing and the differential demodulation on the reception signal, and the high priority data is decoded. After the phase offset component is removed from the phase component of the low priority symbol of the symbol stream, the low priority data is decoded.

A method and receiver systems for demodulating and decoding a hierarchically modulated signal, e.g. an 8PSK signal, are disclosed. An exemplary method includes demodulating and processing (502) the hierarchically modulated signal (202) to produce symbols (212) from the first modulation at the first hierarchical level, applying information (504) from a plurality of the symbols from the first modulation at the first hierarchical level in subtracting (214) from the demodulated hierarchically modulated signal to obtain the second modulation at the second hierarchical level and processing (506) the second modulation at the second hierarchical level to produce second symbols (222) from the demodulated second signal. The hierarchically modulated signal comprises a non-uniform 8PSK signal. Applying the information from the plurality of the symbols from the first modulation can be achieved by applying the symbols after error correction. A decision-directed demodulation of the first modulation can also be used to further improve performance.

Methods and apparatus are presented for supporting the transmission of variable-rate vocoder frames over non-compatible communication channels. Variable-rate vocoder frames are reformatted as cargo in multi-rate vocoder frames. At the receiver, a determination is made as to whether a received multi-rate vocoder frame carries a variable-rate vocoder frame cargo. If a variable-rate vocoder frame is cargo, then a determination of the frame type is made. Various embodiments for conveying cargo information are presented.

A communication system includes a transmitter that transmits both wideband data and narrowband data on a link and a receiver that receives the wideband data and the narrowband data on the link. The receiver demultiplexes the wideband data and the narrowband data into separate data streams so that the link effects transmission of a narrowband channel and a wideband channel. The system achieves high link availability on a link using bandwidth efficient modulation by using a more robust modulation format for the narrowband channel to enable higher link availability for the narrowband channel (carrying the narrowband data on the link) than for the wideband channel. The link may employ bandwidth efficient modulation or may be compatible with prior art wideband modulation formats.

Methods and apparatus are presented for supporting the transmission of variable-rate vocoder frames over non-compatible communication channels. Variable-rate vocoder frames are reformatted as cargo in multi-rate vocoder frames. At the receiver, a determination is made as to whether a received multi-rate vocoder frame carries a variable-rate vocoder frame cargo. If a variable-rate vocoder frame is cargo, then a determination of the frame type is made. Various embodiments for conveying cargo information are presented.

A method of transmitting data. The method includes receiving data to be transmitted to a receiver, determining information on the structure of the received data, segmenting the received data into segments, in a manner determined responsive to the determined structure information and transmitting the segments to the receiver.

When transmitting data from a transmission unit to a reception unit over a channel in a wireless communication system, it has been observed that there are inherent losses in throughput, especially for a channel experiencing high channel quality variations over its frequency range. To improve the throughput over such a channel, it is proposed to: estimate the quality of each subchannel of a channel, classify the subchannels into a number of quality groups based on the estimated quality, and select a code rate per quality group. This selected code rate per quality group is then used when a data word to be transmitted is coded. Simulations have shown that by grouping the subchannels into a limited number of groups, for example one to four groups depending on the channel quality variation, a high throughput could be achieved with a minimum of signaling cost in the form of extra overhead.

A system and method for transmitting data over a channel, in which the data are categorized in at least two different categories. For example, the data are categorized according to the effect on perceived degradation on the data when error mitigation is performed on the data. Corrupted data of the first category are replaced using a first replacement method, such as retransmission and forward error correction. The corrupted data of the second category are replaced using a second replacement method different from the first replacement method, e.g., error mitigation or interpolation.

In a transmission-side data transmission apparatus, a first information component of information data, necessary for real-time reproduction, is transmitted at a first transmission rate that is always secured on a communication channel. The other second information component of the information data, which is necessary for lossless reproduction but not for real-time reproduction, is intermittently transmitted at a second transmission rate that is irregularly secured on the communication channel. On the other hand, in a receiving-side data transmission apparatus, first encoded data that has been transmitted at the first transmission rate is decoded and reproduced in real time. Second encoded data that has been intermittently transmitted at the second transmission rate is decoded and synthesized with the real-time information component, whereby reception information data corresponding to the transmission information data is losslessly reproduced.

A transmitter for use in digital radio communications systems includes: a bit corrector controls bit arrangement in such a manner that a code having high significance, out of multiple codes obtained by coding, is allocated with high priority to a bit having a tendency that the likelihood enlarges at the time of symbol decision on a receiver; a multi-level modulator allocates the code to the multiple bits in accordance with a predetermined symbol arrangement; and a symbol arrangement controller controls the symbol arrangement from equal distance arrangement to another arrangement in accordance with a ratio of the codes different in significance. To control symbol arrangement increases the effect of bit correction and improves an error rate on the receiver.

A communication method, and a processing in accordance with the priority can be performed with a simple configuration even in the case of the communication of the multi-carrier method.The sub-carriers on which high priority data is superimposed and the sub-carriers on which low priority data is superimposed are positioned alternately to be transmitted. At the receiving side, the reception symbol stream in which symbols are lined on the frequency axis is obtained by performing a predetermined reception processing. The delayed symbol stream in which the reception symbol stream is delayed for a predetermined time is added to the reception symbol stream to extract the signal components relating to the high priority data, so that the high priority data is decoded. Thus, the high priority data can be decoded promptly with a simple configuration, and a processing in accordance with the priority can be performed with a simple configuration even if the high priority data and the low priority data are transmitted at the same time by the multi-carrier method.

An apparatus and method for transmitting / receiving an HS-SCCH in an HSDPA communication system including an HS-DSCH shared among a plurality of UEs and spread with a plurality of channelization codes, and the HS-SCCH for transmitting control information related with the HS-DSCH to enable the UEs to receive the shared channel. In the HS-SCCH transmitting apparatus, the control information is prioritized according to its processing urgency degree. High-priority control information and low-priority control information are generated and encoded in different encoding methods. Then the high-priority control information and the low-priority control information are multiplexed to a control channel signal such that the high-priority control information precedes the low-priority control information.

Methods and systems for reporting Channel State Information (CSI), including ordering of CSI in Uplink Control Information (UCI), are provided herein. According to one embodiment, a method performed in a wireless device for reporting CSI comprises at least one of: receiving an indication of a resource allocation for an UL transmission; determining, from the indication, a maximum container size for a CSI report; mapping the one or more information bits of a CSI report to a bitstream, optionally such that a first CSI subset is mapped to more significant bits than a second CSI subset; and omitting the one or more least significant bits of the bitstream.

A method for selective forward error correction of a data stream is disclosed. The method comprises: identifying data segments of different importance and assigning them with corresponding levels of priority; and generating forward error correction data corresponding to only to data segments assigned with levels of priority above a predetermined level of priority.

Disclosed is a communication system in which appropriate retransmission control operations are respectively performed for two data types including real time data and non-real time data, and the transmitter and the receiver used for this communication system. A data type identifier identifies a data type as real time or non-real time, and based on the identified data type, a controller, and another controller (not shown) adjust parameters used for retransmission control.

A method and an apparatus for transmitting error-tolerant data is disclosed employing the ARQ technique, wherein the retransmission of erroneous data is performed up to the point where the remaining amount of errors is acceptable (for instance because the erorrs will not be perceived by the recipient of the information, which can be a person or a higher level protocol with additional error correction capabilities). The number of data blocks (RLC) detected as erroneous is employed to define a reliability measure (RM) and a request for retransmission of the erroneous data blocks is performed until a desired reliability threshold (RT) is reached. An additional threshold with a higher value than the first one can be employed to request for optional retransmission when the reliability measure (RM) is between the first and the second threshold. The retransmission will be performed only if further conditions such as channel availability are met.

A method for transmitting prioritized data encoded by a Forward Error Coding operation wherein a media object is separated into different classes of data forming a base layer and at least one enhancement layer of information, with each layer having associated parity data. Data of the separated media object, formed of classified data, is later encoded and stored, whereby information of the base layer is assigned a higher priority for transmission than enhancement layer data. Such priority classifications are used when a server transmits the classified data over a network fabric as prioritized data. Optionally, the composition of transmitted classified data is adjusted in view of a change in network conditions.