Abstract: This invention provides a method for jointly optimizing network coding, channel coding, and signal constellations in non-coherent wireless multiple-input multiple-output (MIMO) wireless relay networks for the case when transceivers cannot obtain any knowledge of channel state information (CSI) due to high-speed mobility of the transceivers. In the relay networks, two terminal transceivers simultaneously transmit data to an intermediate relaying transceiver, which in turn broadcasts mixed data using physical-layer network coding to both terminals. The embodiments of this invention exploit different blind space-time trellis-coded modulations (ST-TCM) for each user, whose codebook is jointly generated over a Grassmannian manifold. The method is provided by exponential mapping with affine-lattice convolution for joint optimization of channel coding, modulations, and network coding. The method is designed for fast fading channels with and without interleaving.

Abstract: A printer and printer control method can report information about ink consumption to the host computer. The printer 100 is in communication with a host computer 300, and prints according to print jobs sent from the host computer 300. The printer 100 has a job data memory 190 for storing information about each print job. A receiver 110 receives the print jobs from the host computer 300. A print controller 150 controls printing on paper using a predetermined ink according to the print job. A printing evaluator 175 evaluates the result of printing a print job. A ink shot count converter 170 calculates the number of ink shots used to print the print job. A job data manager 180 stores the job ID for the print job and the ink shot count used to print the print job linked to the print result determined for printing the print job in the job data memory 190.

Abstract: A printer 240 calculates the amount of ink used only for printing as a number of discharged ink shots, and sends this shot count with the printer serial number and ink cartridge ID to a server 220. The server 220 saves the shot count, printer serial number, ink cartridge ID, and an error correction code as status information. The server 220 or server upstream from the server 220 can reliably determine the number of ink shots used by the printer 240 only for printing from this status information.

Abstract: The first and second nodes in a wireless network estimate first and second channel response. The first node quantizes the first channel response to produce a first bit sequence, and a feed-forward message, which is transmit as a feed-forward message to the second node. The second node quantizes the second channel response using the feed-forward message to produce and an estimate of the first bit sequence, a second bit sequence and a feed-back message, which is transmitted to the first node. Then, the first and second nodes delete bits in the respective bit sequences using the feed-back and feed-forward message to generate first and second private keys with low bit mismatch rate.

Abstract: A method equalizes and decodes a received signal including a sequence of symbols. Subsequences of the signal are selected, wherein the subsequences are overlapping and time shifted. For each subsequence, statistics of the channel corresponding to a pattern in the subsequence are selected, wherein the statistics include high-order statistics. A transmitted signal corresponding to the received signal is then estimated based on the statistics.

Abstract: This invention provides a method for exploiting precoder optimization gains and multi-user diversity gains with interference alignment in general MIMO wireless networks including multiple users. Specifically, two embodiments exploit either a gradient-based search or iteratively orthogonalizing inference. The method can achieve near-optimal performance at a low complexity. Furthermore, a scheduling criterion is provided for wireless networks comprised of a large number of mobile stations in each cell. The criterion can be done independently in each cell to significantly reduce information exchanged between base stations in different cells compared to the methods that perform joint scheduling over all cells. The two embodiments can be utilized in a spectrally efficient communications network equipped with relaying nodes.

Abstract: For coherent fiber optic communications, the nonlinear XPolM impairment is the most important issue to realize over-100 Gbps high-speed transmissions. A method provides a way to cancel time-varying XPolM crosstalk by introducing multi-stage adaptive mechanism. In the method, a low-complexity adaptive filtering based on recursive least-squares (RLS) first tracks the time-varying crosstalk along with the per-survivor trellis-state decoding. The estimated channel and the decoded data are then used to calculate the empirical covariance, which is in turn exploited to obtain more accurate channel estimates by means of optimal-weighted least-squares. This is performed with a low-complexity processing over frequency domain with fast Fourier transform. The performance is significantly improved with turbo principle decoding, more specifically, iterative decoding and iterative estimation over a block.

Abstract: A channel matrix is estimated for a channel subject to frequency and time selective fading in a multiple-input multiple-output (MIMO) wireless communication network. The method uses a recursive least-squares (RLS) process and an expectation-maximization (EM) process, based on a L1-Lq regularized sparse regression. The method significantly improves an accuracy of the channel estimation by using high-order matrix extension to obtain covariance matrices. The covariance matrices and an initial estimate are refined by a sparse EM to obtain the final estimate of the channel.

Abstract: A method reduces time-varying polarization crosstalk due to XPolM by transmitting multi-dimensional orthogonal constellations. Three variants of crosstalk-free constellations are provided: Grassmann constellations, unitary constellations, and rotation codes. The method uses the Grassmann constellations and the unitary constellations to deal with fiber nonlinearity by applying as a polarization-time coding. The rotation codes exploit a fiber channel characteristic to improve performance and to reduce computational complexity. The underlying orthogonality behind those constellations enables the receiver to decode it as if there is no polarization crosstalk. Moreover, the required computational complexity at the receiver is significantly reduced because neither crosstalk cancellers nor channel estimators are needed.

Abstract: A method reduces time-varying polarization crosstalk due to XPolM by transmitting multi-dimensional orthogonal constellations. Three variants of crosstalk-free constellations are provided: Grassmann constellations, unitary constellations, and rotation codes. The method uses the Grassmann constellations and the unitary constellations to deal with fiber nonlinearity by applying as a polarization-time coding. The rotation codes exploit a fiber channel characteristic to improve performance and to reduce computational complexity. The underlying orthogonality behind those constellations enables the receiver to decode it as if there is no polarization crosstalk. Moreover, the required computational complexity at the receiver is significantly reduced because neither crosstalk cancellers nor channel estimators are needed.

Abstract: For coherent fiber optic communications, the nonlinear XPolM impairment is the most important issue to realize over-100 Gbps high-speed transmissions. A method provides a way to cancel time-varying XPolM crosstalk by introducing multi-stage adaptive mechanism. In the method, a low-complexity adaptive filtering based on recursive least-squares (RLS) first tracks the time-varying crosstalk along with the per-survivor trellis-state decoding. The estimated channel and the decoded data are then used to calculate the empirical covariance, which is in turn exploited to obtain more accurate channel estimates by means of optimal-weighted least-squares. This is performed with a low-complexity processing over frequency domain with fast Fourier transform. The performance is significantly improved with turbo principle decoding, more specifically, iterative decoding and iterative estimation over a block.

Abstract: A channel matrix is estimated for a channel subject to frequency and time selective fading in a multiple-input multiple-output (MIMO) wireless communication network. The method uses a recursive least-squares (RLS) process and an expectation-maximization (EM) process, based on a L1-Lq regularized sparse regression. The method significantly improves an accuracy of the channel estimation by using high-order matrix extension to obtain covariance matrices. The covariance matrices and an initial estimate are refined by a sparse EM to obtain the final estimate of the channel.

Abstract: This invention provides a method for jointly optimizing network coding, channel coding, and signal constellations in non-coherent wireless multiple-input multiple-output (MIMO) wireless relay networks for the case when transceivers cannot obtain any knowledge of channel state information (CSI) due to high-speed mobility of the transceivers. In the relay networks, two terminal transceivers simultaneously transmit data to an intermediate relaying transceiver, which in turn broadcasts mixed data using physical-layer network coding to both terminals. The embodiments of this invention exploit different blind space-time trellis-coded modulations (ST-TCM) for each user, whose codebook is jointly generated over a Grassmannian manifold. The method is provided by exponential mapping with affine-lattice convolution for joint optimization of channel coding, modulations, and network coding. The method is designed for fast fading channels with and without interleaving.

Abstract: This invention provides a method for exploiting precoder optimization gains and multi-user diversity gains with interference alignment in general MIMO wireless networks including multiple users. Specifically, two embodiments exploit either a gradient-based search or iteratively orthogonalizing inference. The method can achieve near-optimal performance at a low complexity. Furthermore, a scheduling criterion is provided for wireless networks comprised of a large number of mobile stations in each cell. The criterion can be done independently in each cell to significantly reduce information exchanged between base stations in different cells compared to the methods that perform joint scheduling over all cells. The two embodiments can be utilized in a spectrally efficient communications network equipped with relaying nodes.

Abstract: The first and second nodes in a wireless network estimate first and second channel response. The first node quantizes the first channel response to produce a first bit sequence, and a feed-forward message, which is transmit as a feed-forward message to the second node. The second node quantizes the second channel response using the feed-forward message to produce and an estimate of the first bit sequence, a second bit sequence and a feed-back message, which is transmitted to the first node. Then, the first and second nodes delete bits in the respective bit sequences using the feed-back and feed-forward message to generate first and second private keys with low bit mismatch rate.

Abstract: A printing device and a control method for a printing device enable eliminating paper feed error due to slipping between a paper feed roller and recording paper when printing. The control unit of a thermal printer has a slippage calculator that runs a process to calculate slippage between the recording paper and platen roller when conveying the recording paper during printing, and a conveyance distance correction unit that runs a process to correct the paper feed distance of the recording paper when printing to each printing area based on the slippage that was just calculated. The conveyance distance correction unit runs a process that inserts a non-printing area d of a length corresponding to the slippage to one or plural specific positions in the original print image.

Abstract: A printer 240 calculates the amount of ink used only for printing as a number of discharged ink shots, and sends this shot count with the printer serial number and ink cartridge ID to a server 220. The server 220 saves the shot count, printer serial number, ink cartridge ID, and an error correction code as status information. The server 220 or server upstream from the server 220 can reliably determine the number of ink shots used by the printer 240 only for printing from this status information.

Abstract: A printer 240 calculates the amount of ink used only for printing as a number of discharged ink shots, and sends this shot count with the printer serial number and ink cartridge ID to a server 220. The server 220 saves the shot count, printer serial number, ink cartridge ID, and an error correction code as status information. The server 220 or server upstream from the server 220 can reliably determine the number of ink shots used by the printer 240 only for printing from this status information.

Abstract: A recording control device controls a recording mechanism section which performs recording on a recording medium by a recording head. An image expansion section expands data input from the outside to create image data for recording. An image buffer memory temporarily stores the image data created by the image expansion section. A recording control section reads the image data stored in the image buffer memory, and controls the recording mechanism section to record the read image data on the recording medium by the recording head. The recording control section controls a recording speed of the recording mechanism section on the basis of a creation speed of the image data in the image expansion section.

Abstract: The cleaning process best suited to the condition of an inkjet printer is selected and run, thereby removing nozzle clogging without wastefully consuming ink. The first time a cleaning switch 7 is operated a CL1 cleaning process is run. If the cleaning switch 7 is pressed a second time and the print pass count is less than e.g., 400, a CL2 cleaning process that uses more ink than the CL1 process is used to clean the recording head, but if the print pass count is 400 or more, the CL1 cleaning process is used. If the print pass count is less than 400 the third time the switch is operated, the CL2 cleaning process is used, but the CL1 cleaning process is used if the print pass count is 400 or more. If the cleaning switch 7 is operated four or more times and the print pass count is less than 400, a YCL cleaning process that consumes substantially no ink is used to clean the recording head, but if the print pass count is 400 or more, the CL1 cleaning process is used.