335 results about "Turbo decoding" patented technology

Disclosed is a method and communication device for suppressing interference. The method comprises performing, with a turbo decoder (314), at least one turbo decoding attempt (1106) on a received signal (1104). The turbo decoding attempt generates at least one whole word code bit therefrom (1108). The whole word code bit (1108) corresponds to a group of bits comprising a transmitted symbol. The method determines if the whole word code bit (1108) has a confidence level exceeding a given threshold (1110). If the whole word code bit (1108) does have a confidence level exceeding the given threshold, the whole code word bit is selected for use in data symbol recovery (1114).

A system employs space-time coding characterized at the transmitter by bit-interleaved coded modulation (BICM) combined with modulating several streams of the BICM encoded data for transmission over two or more antennas. Space-time coding techniques improve transmission efficiency in radio channels by using multiple transmit and/or receive antennas and coordination of the signaling over these antennas. Bit-interleaved coded modulation provides good diversity gain with higher-order modulation schemes that employ binary convolutional codes. A receiver demodulates the received signals and applies multi-input, multi-output (MIMO) demapping to estimate the BICM encoded bitstream. After deinterleaving of the BICM encoded bitstream, maximum a posteriori (MAP) decoding is applied to the resulting bit stream to generate soft output values. By applying well-known turbo-decoding principles to iteratively demap and decode, the overall receiver performance is significantly improved. The MIMO demapping and MAP decoding processes exchange likelihood information to improve the bit error rate performance over several iterations of demapping/decoding. By generating tentative decisions for transmitted bits, the overall number of evaluations used for demapping may be reduced.

A digital broadcasting system and method, where the digital broadcasting system includes: a transmission stream generator multiplexing a normal stream and a turbo stream to generate a dual transmission stream; a transmitter inserting an supplementary reference signal (SRS) into the dual transmission stream, processing the turbo stream to reconstitute the dual transmission stream, and outputting the reconstituted dual transmission stream; and a receiver receiving the reconstituted dual transmission stream, separately turbo decoding the turbo stream, inserting the turbo decode turbo stream into the dual transmission stream, and decoding the dual transmission stream into which the turbo decoded turbo stream has been inserted, to restore normal stream data and turbo stream data. Thus, reception sensitivity of a digital broadcasting signal can be efficiently improved.

A transmitting system, a receiving system, and a method of processing broadcast signals are disclosed. The receiving system includes a tuner, a channel equalizer, a storage unit, an inner decoder, a deinterleaver, an outer decoder, and an interleaver. The tuner receives a broadcast signal including a data group. The channel equalizer channel-equalizes the broadcast signal. The storage unit stores mobile service data included in the channel-equalized broadcast signal, and repeatedly outputs the stored mobile service data for a predetermined number of turbo decoding iterations. The inner decoder matches the mobile service data being outputted from the storage unit with mobile service data being outer-decoded and fed-back and inner-decodes the matched mobile service data. The deinterleaver deinterleaves the inner-decoded mobile service data in block units. The outer decoder outer-decodes the deinterleaved mobile service data. The interleaver interleaves the outer-decoded mobile service data in block units and feeding-back the interleaved mobile service data to the inner decoder.

An interference symbol determining section 208 compares reception power of a signal at an interference position measured by an interference position reception power measuring section 208B with a reception power value of a desired signal measured by a desired signal measuring section 208D for each subcarrier, thereby determines symbols which should be actually treated as interference symbols and outputs the symbols to a turbo decoding section 209. The turbo decoding section 209 determines whether to calculate LLR values of symbols of each subcarrier signal input from a demodulation section 207 or set the LLR values to “0” based on the comparison result of the interference symbol determining section 208 and executes decoding processing.

A system employs space-time coding characterized at the transmitter by bit-interleaved coded modulation (BICM) combined with multi-carrier Orthogonal Frequency Division Multiplexing (OFDM) modulation. Space-Time coding techniques improve transmission efficiency in radio channels by using multiple transmit and/or receive antennas and coordination of the signaling over these antennas. Bit-interleaved coded modulation provides good diversity gain with higher-order modulation schemes that employ binary convolutional codes. OFDM modulation allows for wideband transmission over frequency selective radio channels. A receiver demodulates the OFDM signal and applies multi-input, multi-output (MIMO) demapping to estimate the BICM encoded bitstream. After deinterleaving of the BICM encoded bitstream, maximum a posteriori (MAP) decoding is applied to the resulting bit stream to generate soft output values. The MIMO demapping and MAP decoding processes exchange likelihood information to improve the bit error rate performance over several iterations of demapping/decoding. By applying well-known turbo-decoding principles to iteratively demap and decode, the overall receiver performance is significantly improved.

In iterative-diversity (ID) transmission systems for signals with concatenated convolutional coding (CCC), paired iterative diversity signals each have ½ the code rate of the 8VSB DTV signals prescribed by the 1995 ATSC Digital Television Broadcast Standard. Known serial concatenated convolutional coding (SCCC) or novel parallel concatenated convolutional coding (PCCC) is used in such system. Pairs of CCC signals code data bits and ones' complemented data bits respectively, using similar coding algorithms. Receivers for this transmission system use respective turbo decoders for turbo decoding the earlier-transmitted and later-transmitted CCC signals. Turbo decoding of the earlier-transmitted portions of iterative diversity signals is delayed to be contemporaneous with turbo decoding of the later-transmitted portions of iterative diversity signals. This facilitates the turbo decoders exchanging information concerning confidence levels of data bits during the turbo decoding procedures.

A UE in an URA_PCH state or a Cell_PCH state receives a HS-PDSCH without an associated HS-SCCH. No dedicated H-RNTI is assigned to the UE. The received HS-PDSCH is separately processed using one or more different predetermined transport format. The different predetermined transport formats are identified from associated HS-DSCH paging system information block. The UE starts blindly processing the received HS-PDSCH by determining a set of configuration parameters according to a first transport format of the identified predetermined transport formats. One or more associated device components such as hardware components of the UE are configured using the determined set of configuration parameters. The configured device components are used to perform HARQ processing, IR combining and/or Turbo decoding on the received HS_PDSCH without associated HS_SCCH. The UE continuously processes the received HS-PDSCH using the next available predetermined transport format when a CRC test completes with an error.

A transmitting system, a receiving system, and a method of processing a broadcast signal are disclosed herein. The receiving system include a tuner, a demodulator, a block decoder, an RS frame decoder, and a service manager. The tuner receives a broadcast signal. Herein the broadcast signal includes mobile service data, a service map table signaling access information of the mobile service data, and a plurality of known data sequences. The mobile service data and the service map table are packetized to an RS frame. The demodulator demodulates the received broadcast signal. The block decoder turbo-decodes the mobile service data and the service map table included in the demodulated broadcast signal in block units. The RS frame decoder forming an RS frame including the turbo-decoded mobile service data and service map table, performs primary first cyclic redundancy check (CRC)-decoding and RS-decoding, and performs secondary CRC-decoding on the primarily CRC-decoded and RS-decoded RS frame. The service manager acquires source IP address information of IP datagrams of the RS frame-decoded mobile service data from the service map table.

Source nodes in an International Mobile Telecommunications (IMT)-advanced 4G network transmit data on uplink channels to a relay node and a BS using a channel code. The relay node decodes independently the data received from each source node, and applies network coding to data correctly decoded, and transmits the encoded data to the BS. The BS decodes the encoded data transmitted by the sources nodes and the relay nodes cooperatively via a turbo decoding process. The data from each source node are decoded by soft-input soft-output single user decoders and are decoded, together with the data from the relay node, by a soft-input soft-output multi-user decoder.

Receivers with capability for iterative-diversity reception of COFDM digital television transmissions of repeated similarly coded data are described. Also described are receivers with capabilities for receiving COFDM digital television transmissions in which earlier transmissions of coded data are later followed by subsequent transmissions of the same data differently coded. The receivers use maximal-ratio code combining techniques for repeated components in the COFDM digital television transmissions. The receivers use turbo decoding techniques for concatenated coding of data in the COFDM digital television transmissions.

The outer convolutional coding of the signals used to transmit mobile-handheld (M/H) service data within digital-television (DTV) signals is subjected to anti-Gray coding, either before or after its interleaving, but before its inner convolutional coding. In a receiver for such M/H-service data, portions of the trellis decoded DTV signal containing soft decisions concerning symbol-interleaved convolutionally coded M/H-service data are recoded for a Gray-code mapping of symbols to modulation levels. This is done either before or after symbol de-interleaving, but before decoding the outer convolutional coding. Soft decisions concerning extrinsic information to be fed back to the ⅔ trellis decoder to close a turbo decoding loop are derived from soft decisions as to the M/H-service data, which derivation includes re-coding for a binary-code mapping of symbols to modulation levels. Each re-coding procedure can be performed using ROM, but preferably is performed using simple digital logic.

Provided are a method and an apparatus for parallel Turbo decoding in LTE, comprising: storing input check soft bits and a frame to be decoded, when storing said frame, dividing the frame into blocks, storing each block respectively as system soft bits; simultaneously performing component decoding once for several blocks of one said frame, and in the process of component decoding, dividing each block into several sliding windows according to a sliding window algorithm, calculating the following parameters according to system soft bits, check soft bits and priori information: branch metric value γ, forward state vector α, backward state vector β, LLR, and priori information, storing the priori information for use in a next component decoding; completing a decoding process after several component decoding; performing a hard decision on LLR, and if judged that a result of the hard decision meets an iteration ending condition, outputting a decoding result, otherwise, performing next iteration decoding.

This disclosure relates to providing negative stopping criteria for turbo decoding for a wireless device. A device may wirelessly receive turbo coded data. Turbo decoding may be performed on the turbo coded data. Performing turbo decoding may use one or more negative stopping criteria for early termination of the turbo decoding for each code block of the turbo coded data. The negative stopping criteria may be selected to terminate the turbo decoding of a code block early under poor wireless medium conditions. Turbo decoding of a code block may be terminated early if the one or more negative stopping criteria for the code block are met.

A transmitting system, a receiving system, and a method for processing a broadcast signal are disclosed. The receiving system comprises a tuner, a channel equalizer, a turbo decoder, a demultiplexer, a first error correction decoder, a block deinterleaver, and a second error correction decoder. The tuner receives a broadcast signal including a data group. The data group comprises mobile service data, regularly spaced known data sequences, and signaling data. The turbo decoder performs turbo decoding for the signaling data included in the channel equalized broadcast signal in the channel equalizer. The block deinterleaver performs block deinterleaving for the turbo-decoded FIC data in a block unit of TNoG (the number of all data groups assigned to one subframe)×51 bytes.

In a method for transmitting data in a digital transmission system given packet-switched service, for purposes of channel coding, a turbo-coding is performed in a turbo-coder at the sender side and a turbo-decoding with soft decision output signals is performed in a turbo-decoder at the receiver side. To trigger an ARQ, the channel quality is estimated by a parameter estimation method; the variances of the soft decision output signals at the turbo-decoder are determined; the correctness or respectively, defectiveness of the transmitted packet is inferred from the channel quality and the variances; and a retransmission of at least a part of defective packet is triggered. In the retransmission of the information of a defective packet, at least part of the information suppressed by the dotting in the precious transmission is sent. This additional information is [. . .] inserted into the already existing information at the receiver side, and this complete information is decoded again.

Removing adverse effects in case error detection using error detection codes cannot be performed correctly, and improving the data transmission efficiency. The turbo decoder 6 compares data which is decoded this time with data which is decoded previous time, both of which are decoded in repetitive decoding processing, to obtain discord number information indicative of the number of discordant sign bits, and sends the information to a terminal I/F unit 7 and a packet flow retransmission controlling unit 10. Even though it is determined that error detection result from a CRC recalculating unit 9 shows that there exists no bit error, in case the number of discordant sign bits is larger than a predetermined threshold value, it is determined that there is generated error. And, a packet flow retransmission controlling unit 10 sends a signal requesting retransmission of data. Furthermore, data amount to be retransmitted is varied in accordance with the number of discordant sign bits to improve the data transmission efficiency.

Turbo encoded information that comprises first systematic bits, first parity bits, second systematic bits, and second parity bits is decoded by supplying the first systematic bits and the first parity bits to a first decoder; supplying the second systematic bits and the second parity bits to a second decoder; and operating the first and second decoders in parallel for a number, m, of half-iterations, wherein m≧1. For each of the m half-iterations, the first decoder utilizes soft information supplied as an output from the second decoder in a preceding half-iteration, and the second decoder utilizes soft information supplied as an output from the first decoder in the preceding half-iteration. An early iteration termination decision is made by, after one or more of the m half-iterations, deciding whether to stop operating the first and second decoders by comparing an output from the first decoder with an output from the second decoder.

An Forward Error Correction (FEC) apparatus and method for reducing Bit error rates (BER) and Frame Error Rates (FER) using turbo decoding in a digital communication system. In a constituent decoder for decoding a turbo code, a first adder calculates the LLR of a received code symbol by calculating the difference between the probability of the code symbol being 1 and that of the code symbol being 0 at an arbitrary state of a turbo decoding trellis. A second adder adds the transmission information and a priori information of the code symbol. A third adder calculates the difference between the outputs of the first and second adders as extrinsic information. A first multiplier multiplies the output of the third adder by a predetermined weighting factor as a feedback gain. A correction value calculator calculates a correction value using the difference between the best metric and the second best metric of the code symbol. A fourth adder adds the correction value to the output of the first multiplier.

The invention discloses a novel conflict-free interleaver-based low delay parallel Turbo decoding method, which mainly solves the problem of high decoding delay in MAP algorithms due to iteration and recursive calculation. The method comprises the following steps of: blocking and windowing the received channel information; initializing prior information and state measurement initial values; making a primary soft input and soft output processor (SISO I) and a secondary soft input and soft output processor (SISO II) to synchronously slide forwards to decode; interleaving and de-interleaving the external information generated by the SISO I and the SISO II by using a novel conflict-free interleaver respectively; and when the iteration reaches the maximum iteration times, comparing the obtained likelihood ratio L (xk) with the threshold 0, and performing hard decision to obtain an estimation value of decoding bit. The method has the advantages of low decoding delay, high throughput rate, low performance loss and the like, and can be used for a Turbo decoder of a long term evolution (LTE) receiver.

A receiving system and a method of processing data are disclosed herein. The receiving system a signal receiving unit, a known sequence detector, a first equalization unit, a second equalization unit, a block decoder, and an error correction unit. The signal receiving unit receives a broadcast signal including a data group multiplexed mobile service data with a plurality of known data sequences. The known sequence detector detects known data sequences from the broadcast signal. The first equalization unit updates an equalization coefficient by using the known data sequence during the known data section, thereby primarily channel-equalizing the known data sequence. The second equalization unit interpolates or extrapolates a converging equalization coefficient, thereby secondarily channel-equalizing the mobile service data, when the equalization coefficient converge. The block decoder performs turbo-decoding on the channel-equalized mobile service data in block units. And, the error correction unit performs error correction decoder on the decoded mobile service data, thereby correcting errors generated in the mobile service data.

A decoding device having a turbo decoder and an RS decoder concatenated serially and a method of decoding performed by the same. A turbo decoder decodes received data of a channel and an RS decoder RS decodes the turbo decoded data. A controller controls the turbo decoder to iteratively turbo-decode the data according to a number of iterations determined by a stored iteration number and to cease the turbo decoding if an error correction completion signal is received from the RS decoder. The controller decreases the iteration number for a next frame of the data if the completion signal is received within the predetermined number of iterations and increases the iteration number for a next frame if the completion signal is not received within the predetermined number of iterations. The iteration number is changeable within maximum and minimum limits and may exceed the maximum limit in special cases.

The invention discloses a communication method of underwater digital voice and relates to a communication method. The communication method comprises the following steps of: at a communication transmitting end, sampling input simulated voice by using an analogue to digital (A/D) converter so as to obtain digital voice, performing mixed excitation linear prediction (MELP) low-speed compression coding on the digital voice so as to obtain voice data, grouping and performing Turbo coding on a voice data bit stream so as to obtain different groups of data, performing orthogonal frequency division multiplexing (OFDM) multicarrier modulation on every group of data and converting a modulated signal into a sound wave through an underwater acoustic transducer for transmitting in a sea underwater sound channel; and at a communication receiving end, performing underwater sound OFDM multicarrier modulation on a received signal after synchronization so as to obtain demodulation data, performing Turbo decoding on the demodulation data, performing MELP decoding on the data so as to synthesize the digital voice, converting the digital voice into simulated voice by using a digital to analogue (D/A) converter and outputting the simulated voice through a loudspeaker.