46results about "Multiplex code type" patented technology

A method and apparatus for physically secure communication over machine-to-machine (M2M) networks is claimed, through the use of frequency-hop and random access spread spectrum modulation formats employing using truly random spreading codes and time/frequency hopping and receiver selection strategies at the transmitters in the M2M network, blind signal detection and linear signal separation techniques at the receivers in the M2M network, completely eliminating the ability for an adversary to predict and override M2M transmissions. Additional physical security protocols are also introduced that allow the network to easily detect and identify spoofing transmissions on uplinks and downlinks, and to automatically excise those transmissions as part of the despreading procedure, even if those transmissions are received at a much higher power level than the intended transmissions. Extensions to weakly and strongly macrodiverse networks are also described, which provide additional efficiency and security improvements by exploiting the route diversity of the network.

A method for transmitting signals based on dual sensing in a wireless communication system is disclosed. One or more sensor nodes receive Gaussian codes corresponding respectively to the one or more sensor nodes, allocated from a fusion center. The one or more sensor nodes determine whether to operate at a specific time. At least one sensor node that has determined to operate among the one or more sensor nodes multiplies the Gaussian codes by a transmission signal and transmits the multiplied signal to the fusion center.

A UWB system comprising a plurality of piconets, wherein each piconet uses a different code to generate a preamble for use in communicating with a plurality of remote communication devices. The preamble can be generated from the combination of repeated versions of the code, negative versions of the code, and no code or zero, the codes used have a perfect autocorrelation function and optimal cross-correlation.

To enable low latency uplink to be used in a more preferable mode can be provided. A device includes: a communication unit configured to perform radio communication; and a control unit configured to perform control such that control information is transmitted from the communication unit to a terminal, the control information indicating that a communication scheme in which data non-orthogonally multiplexed for a plurality of layers is demodulated through cancellation of interference between the layers and in which the data is transmitted from the terminal to a base station through a predetermined uplink resource, is available.

Disclosed are an apparatus and method for constant amplitude encoding of a transmission signal in a CDM (Code Division Multiplexing) communication system. The apparatus for constant amplitude encoding of a transmission signal includes: an encoding module sequentially performing horizontal encoding and vertical encoding on an input signal; and a spreading and multiplexing module spreading the signal which has been encoded by the encoding module and multiplexing the spread signal in a vertical direction to output a data stream having a constant amplitude.

A method is provided of receiving user data from multiple transmitters, the user data from each transmitter having been encoded as a Low Density Lattice codeword, and the multiple Low Density Lattice codewords having been transmitted so as to be received as a combined signal at a receiver, the method of receiving comprising the steps of: (i) receiving the signal, (ii) calculating coefficients of linear combinations of the codewords from the multiple transmitters, (iii) calculating a scaling factor to be applied to the signal based on the coefficients, (iv) applying the scaling factor to the signal to provide a linear combination of the codewords, (v) decoding the linear combination of the codewords based on channel state information to obtain an optimal independent linear combination of user data, (vi) repeating steps (ii), (iii) (iv) and (v) to obtain at least as many optimal independent linear combinations as the number of transmitters, and recovering the user data from the optimal independent linear combinations.

The invention provides a soft spreading code optical selection method of a mixed spread spectrum multiple-access network; the method comprises the following steps: setting limit conditions according to structure characteristics of a cyclic shift keying (CCSK) code, and forming a code database satisfying proportionality and autocorrelation requirements; employing an origin traversal-initial random-end segment directed segmented search method to screen a set of soft spreading codes satisfying cross correlation requirements from the autocorrelation code database; finally combining with a frequency hopping pattern so as to reasonably distribute the soft spreading codes to each network for usage. The method can effectively reduce the internetwork interferences, thus improving the system networking ability.

A wireless communication device, a wireless communication system and a method of avoiding collisions by transmitting a packet length field before transmitting a header of the packet.

The invention provides a low-correlation code set construction method based on cross-correlation matrix concentration. The method comprises the steps that a code space is traversed to form a balanced code set; codes with the excellent self-correlation property are found out, and an excellent self-correlation code set is formed; cyclically equivalent codes are removed from the excellent self-correlation code set, and an alternative code set is formed; pairwise cross-correlation value vectors of all the codes are calculated, and peak values of the pairwise cross-correlation value vectors are selected to form a cross-correlation matrix; the cross-correlation matrix is converted into a cross-correlation 01 matrix and concentrated into a full 1 matrix; the codes corresponding to the full 1 matrix form an optimum code set, the alternative codes which have good cross-correlation with all the codes in the optimum code set are added, and the low-correlation code set is formed. According to the method, the low-correlation code set in which the codes are flexible in length range and excellent in correlation property is generated, and the code number in the set is considerable.

In one embodiment, a method for blindly detecting low density spreading (LDS) active signatures including receiving, by a first node from a second node, a signal and decorrelating the signal in accordance with a signature list to obtain an active signature list. The method also includes decoding the signal in accordance with the active signature list to obtain a decoded signal.

[Object] To provide a communication control apparatus, a radio communication apparatus, a communication control method, a radio communication method, and a program that are capable of contributing to improving a radio communication technology related to IDMA. [Solution] Provided is a communication control apparatus including: a communication unit configured to communicate with a radio communication apparatus of a radio communication system using interleave division multiple access (IDMA); and a control unit configured to allocate an interleaver type of an interleaver to be used for IDMA by the radio communication apparatus.

A transmitter apparatus in a wireless communication system that includes a processor. In one embodiment, the processor is configured to receive at least one modulated data message and spread the at least one modulated data message into a transmission signal using a low density signature matrix. The low density signature matrix is a cycle-free signature matrix. A receiver apparatus is configured toreceive the transmission signal and detect within the received transmission signal at least one modulated data message. The processor is configured to detect the at least one modulated data message in one iteration using the cycle-free signature matrix. Such cycle-free signature matrices are constructed as a concatenation of phase rotating identity matrices and all-zero matrices.

The invention discloses a novel method for designing a perfect Gaussian integer sequence embedded with a preset Gaussian integer, the obtained sequence has a period of 3N, N is an even number, (N, 3)= 1, and the obtained sequence has an auto-correlation function similar to impulse. For any Gaussian integer c = n1 + n2j (j2 =-1) preset by a sequence designer, N-2 c is embedded as a symbol in the perfect Gaussian integer sequence generated by the method of the present invention. The method can be applied to signal processing, communication systems and large-scale integrated circuit testing.