A method for providing digital communication over an acoustic channel is disclosed. The method includes dividing an operating frequency band of the acoustic channel into multiple adjacent non-overlapping subbands of an equal bandwidth, selecting subbands based on a symbol to be transmitted, generating a signal with linear frequency modulation in each of the selected subbands, combining the signals with linear frequency modulation, and transmitting the combined signals to the acoustic channel through an acoustic system, wherein slopes of linear frequency modulation for the signals with linear frequency modulation are equal.

A receiving device includes an equalization processor including multiple delay equalizers. The equalization processor is configured to: obtain a first error between an output of one specific tap in the multiple delay equalizers and a predetermined reference value, and calculate a first weight with which the first error is minimized; cause a calculation result of the first weight to be reflected in all taps in the multiple delay equalizers except the specific tap, obtain a second error between outputs of all taps in the multiple delay equalizers and the predetermined reference value, and calculate a second weight with which the second error is minimized; and update coefficients of all taps in the multiple delay equalizers at the same timing using the calculation result of the first weight and a calculation result of the second weight, and calculate an output of the equalization processor.

An apparatus is disclosed, comprising means for identifying a plurality of user equipment (UE), each transmitting one or more uplink packets for decoding at a base station associated with a given cell of a radio network. The apparatus further comprises means for clustering the identified user equipment into joint processing groups, each joint processing group comprising the identities of two or more user equipment as clustered and means for performing, in a first processing stage, joint processing of the uplink data streams for identified user equipment within common joint processing groups using one or more first processing algorithms to produce corresponding first processed uplink data streams. The apparatus further discloses means for performing one or more subsequent processing stages on the first processed uplink data streams, subsequent to the joint processing, to produce decoded uplink data streams, the one or more subsequent processing stages using one or more second processing algorithms, different from the first processing algorithm.

A method for providing digital communication over an acoustic channel is disclosed. The method includes dividing an operating frequency band of the acoustic channel into multiple adjacent non-overlapping subbands of an equal bandwidth, selecting subbands based on a symbol to be transmitted, generating a signal with linear frequency modulation in each of the selected subbands, combining the signals with linear frequency modulation, and transmitting the combined signals to the acoustic channel through an acoustic system, wherein slopes of linear frequency modulation for the signals with linear frequency modulation are equal.

A transmitter for transmitting data to a receiver of a wireless communication network, the transmitter includes at least one antenna, a codebook, an encoder, and a transceiver coupled to the encoder and to the at least one antenna. The codebook includes a plurality of codewords, each codeword being a vector including a plurality of symbols, each symbol to be transmitted over resources of the wireless communication network. The encoder is configured to receive an information message to be transmitted to a receiver of the wireless communication network, to select from the codebook the codeword associated with the received information message, and to divide the selected codeword into a plurality of sub-codewords. The transceiver is configured to transmit via the at least one antenna a first sub-codeword, and to transmit via the at least one antenna a second sub-codeword responsive to an indication that the encoded information message was not successfully decoded at the receiver on the basis of the received first sub-codeword.

An apparatus is disclosed, comprising means for identifying a plurality of user equipment (UE), each transmitting one or more uplink packets for decoding at a base station associated with a given cell of a radio network. The apparatus further comprises means for clustering the identified user equipment into joint processing groups, each joint processing group comprising the identities of two or more user equipment as clustered and means for performing, in a first processing stage, joint processing of the uplink data streams for identified user equipment within common joint processing groups using one or more first processing algorithms to produce corresponding first processed uplink data streams. The apparatus further discloses means for performing one or more subsequent processing stages on the first processed uplink data streams, subsequent to the joint processing, to produce decoded uplink data streams, the one or more subsequent processing stages using one or more second processing algorithms, different from the first processing algorithm.

A method for providing digital communication over an acoustic channel is disclosed. The method includes dividing an operating frequency band of the acoustic channel into multiple adjacent non-overlapping subbands of an equal bandwidth, selecting subbands based on a symbol to be transmitted, generating a signal with linear frequency modulation in each of the selected subbands, combining the signals with linear frequency modulation, and transmitting the combined signals to the acoustic channel through an acoustic system, wherein slopes of linear frequency modulation for the signals with linear frequency modulation are equal.

A receiving device includes an equalization processor including multiple delay equalizers. The equalization processor is configured to: obtain a first error between an output of one specific tap in the multiple delay equalizers and a predetermined reference value, and calculate a first weight with which the first error is minimized; cause a calculation result of the first weight to be reflected in all taps in the multiple delay equalizers except the specific tap, obtain a second error between outputs of all taps in the multiple delay equalizers and the predetermined reference value, and calculate a second weight with which the second error is minimized; and update coefficients of all taps in the multiple delay equalizers at the same timing using the calculation result of the first weight and a calculation result of the second weight, and calculate an output of the equalization processor.

A receiver for receiving a signal including a plurality of symbols through a multiple input multiple output (MIMO) channel, and an operation method of the receiver are provided. The receiver includes a demodulator configured to calculate, for each physical channel, Euclidean distances of one or more of the received symbols with respect to all candidate vectors included in an initial candidate vector set and to output information about the Euclidean distances. A vector set detector may select, based on the information, one of a plurality of candidate vector sets having different sizes, as a subsequent candidate vector set for calculating a log likelihood ratio (LLR) of other symbols of the plurality of symbols or an LLR with respect to a second signal received following the first signal.

A transmitter for transmitting data to a receiver of a wireless communication network, the transmitter includes at least one antenna, a codebook, an encoder, and a transceiver coupled to the encoder and to the at least one antenna. The codebook includes a plurality of codewords, each codeword being a vector including a plurality of symbols, each symbol to be transmitted over resources of the wireless communication network. The encoder is configured to receive an information message to be transmitted to a receiver of the wireless communication network, to select from the codebook the codeword associated with the received information message, and to divide the selected codeword into a plurality of sub-codewords. The transceiver is configured to transmit via the at least one antenna a first sub-codeword, and to transmit via the at least one antenna a second sub-codeword responsive to an indication that the encoded information message was not successfully decoded at the receiver on the basis of the received first sub-codeword.