47results about "Multiplex code type" patented technology

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.

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.

Method and apparatus embodiments are provided for low complexity message passing algorithm (MPA) detection with substantially minor or tolerated performance loss compared to the standard MPA. A method includes calculating, at a detector, a plurality of function nodes (FNs) according to a plurality of received multiplexing signals for a one or a plurality of user equipments (UEs) using a plurality of first MPA computations that map a plurality of variable nodes (VNs) corresponding to the UEs to the FNs and using a priori information in an initial vector of probabilities for each of the VNs, excluding from the first MPA computations a plurality of first relatively small multiplication terms, updating the probabilities for the VNs using the last calculated FNs and a plurality of second MPA computations that map the FNs to the VNs, and excluding a plurality of second relatively small multiplication terms from the second MPA calculations.

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.

Signals with unpredictable transmission properties enabling physically secure, unscheduled and interference-resistant machine-to-machine (M2M) communication are described. A physical dwell structure containing time slots and frequency channels is established, and a combination of unpredictable physical dwells, spread spectrum modulation with unpredictable spreading vectors, and unpredictable selection of intended receivers is described. These unpredictable transmission properties enable receivers to detect and extract transmissions intended for the receiver, and excise transmissions not intended for the receiver, even if they are received at much higher power levels than the intended transmissions. The system eliminates the ability for an adversary to predict and override M2M transmissions; allows reception of ad-hoc transmissions in dense environments without scheduling, carrier-sense multiple access with collision avoidance (CSMA / CA) protocols, or scheduling feedback paths; and allows macrodiverse reception of transmissions at networks of connected receivers, thereby providing additional efficiency and security improvements exploiting route diversity of the network.

In order 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, a communication control apparatus is provided. The communication control apparatus includes 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.

Disclosed are methods and apparatus used in wireless communications. The methods and apparatus establish a codebook for use in sparse code multiple access (SCMA) encoded communications, in particular. The SCMA codebook is configured to set the codebook for at least one layer (i.e., a user) to include a constellation of points having a first grouping of constellation points located at first radial distance from an origin in a complex plane and a second grouping of constellation points located at a second radial distance from the origin. This codebook arrangement provides increased gains at receivers by optimizing the constellation shape to improve the distance between constellation points (i.e., SCMA codebook performance), and in particular more robust performance when encountering amplitude and phase misalignment in uplink (UL) multiple access.

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.

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.

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.

The present invention discloses a new method for designing a perfect Gaussian integer sequence embedded with preset Gaussian integers. The obtained sequence has a period of 3N, where N is an even number, and (N, 3)=1, and has an impulse-like autocorrelation function. For any Gaussian integer c=n preset by the sequence designer 1 +n 2 j(j 2 =-1), N-2 c are embedded in the perfect Gaussian integer sequence produced by the method of the present invention as code elements. The invention can be applied to signal processing, communication system and large-scale integrated circuit test.

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.