301results 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 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 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 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 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.

Methods and apparatus for delivering data objects from an electronic device or system over a packet-switched network are provided, wherein source data is represented by encoded symbols in packets such that the source data is recoverable, at least approximately, from the encoded symbols, by arranging the source data into a plurality of source symbols, generating a plurality of encoding packets, wherein an encoding packet comprises a universal object symbol identifier (“UOSI”) and a plurality of encoding symbols representing source data for a packet structure identified by the UOSI, and sending the plurality of encoding packets to the packet-switched network.

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.

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 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.

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.

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.