Abstract: This invention provides a joint user clustering and power allocation method and a base station using the same. They are applicable to cooperative non-orthogonal multiple access (NOMA) systems. The method includes: sorting K user equipment devices (UEs) according to the K channel gains between the base station and the K UEs, and then establishing a strong user candidate group of K/2 UEs and a weak user candidate group of K/2 UEs; pairing each of the UEs in the strong user candidate group with each of the UEs in the weak user candidate group so as to divide the K UEs into K/2 clusters, where the power allocation coefficients for each pair of UEs are also calculated during the paring process; and transmitting messages to the K UEs based on the calculated power allocation coefficients of the K/2 clusters.

Abstract: A transmitting device, for handling signal interference, comprises a first transmitting circuit, for processing a first plurality of baseband signals, to generate a first plurality of radio frequency signals; a second transmitting circuit, for processing a second plurality of baseband signals and a plurality of input signals, to generate a second plurality of radio frequency signals; a feedback circuit, coupled to the second transmitting circuit, for processing the second plurality of radio frequency signals and a plurality of leakage signals, to generate a plurality of error signals; and a control circuit, coupled to the first transmitting circuit, the second transmitting circuit and the feedback circuit, for generating the plurality of input signals according to the first plurality of baseband signals and the plurality of error signals.

Abstract: This invention provides a relay precoder selection method for two-way amplify-and-forward multiple-input multiple-output (MIMO) relay systems and communication devices using the selection method or the selected relay precoder. According to the relationship between a relay precoder and the singular values of the effective MIMO channels, a set of candidate relay precoders are constructed based on the singular vector subspaces of cascaded MIMO channels, and one of them is selected for meeting a specific design criterion, such as the minimum sum of mean-squared errors, the maximum sum of channel capacities, and the minimum or maximum sum of condition numbers, where the condition number is defined as the ratio of the largest to the smallest singular value of a MIMO channel. As compared with the iterative design methods with the best performance, this invention achieves close performance while requiring much lower computational complexity.

Abstract: A method of interference cancellation includes the following steps: performing a take-energy operation on a to-be-sent signal at multiple times to generate multiple to-be-sent signal powers; performing a first high-pass operation on the to-be-sent signal powers to generate a to-be-sent high-pass result; performing a second high-pass operation on a received signal to generate a received high-pass result; adjusting multiple filter coefficients according to the to-be-sent high-pass result and the received high-pass result; and generating a recover signal according to the filter coefficients.

Abstract: This invention discloses a multicarrier communication system that includes a transmitter equipment and a receiver equipment. According to a timing scheme, the transmitter equipment processes multiple original symbols for transmission on multiple subcarrier channels, and the receiver equipment processes and detects multiple received symbols from the multiple subcarrier channels. During a time frame of data transmission, the initial three of the original symbols for each of the subcarrier channels are three pilot symbols, forming a preamble. The three preambles of every consecutive three of the subcarrier channels form a preamble unit. All the pilot symbols of the preamble unit are expressed as a 3×3 matrix. When the center pilot symbol of the preamble unit is normalized to 1 or j (i.e., the imaginary unit), the matrix is [ - j - j - j j 1 - j - j j - j ] ? ? or ? [ 1 1 1 - 1 j 1 1 - 1 1 ] .

Abstract: This invention provides a joint power allocation, precoding, and decoding method and a base station thereof. They are applicable to multiple-input multiple-output non-orthogonal multiple access (MIMO-NOMA) systems. The method includes: (1) decomposing the precoder for each cluster into a first precoder and a second precoder; (2) obtaining the mean-squared error (MSE) functions of the decoded signals for all user equipment devices in each cluster; (3) calculating the power allocation factors for each cluster in the case of minimizing the maximum of all the MSE functions in each cluster; and (4) obtaining the second precoder and the decoders for each cluster in the case of minimizing a sum of the MSE functions of the decoded signals for all user equipment devices in all clusters under a total power constraint according to the power allocation factors.

Abstract: This invention provides a joint power allocation, precoding, and decoding method and a base station thereof. They are applicable to multiple-input multiple-output non-orthogonal multiple access (MIMO-NOMA) systems. The method includes: (1) decomposing the precoder for each cluster into a first precoder and a second precoder; (2) obtaining the mean-squared error (MSE) functions of the decoded signals for all user equipment devices in each cluster; (3) calculating the power allocation factors for each cluster in the case of minimizing the maximum of all the MSE functions in each cluster; and (4) obtaining the second precoder and the decoders for each cluster in the case of minimizing a sum of the MSE functions of the decoded signals for all user equipment devices in all clusters under a total power constraint according to the power allocation factors.

Abstract: An antenna beam searching method uses a balance puzzle concept to perform group division of a plurality of antenna beams supported by a transmitter end, so as to perform evaluation on the antenna beam group(s) thus divided to determine an angle of departure of the transmitter end.

Abstract: This invention provides a joint user clustering and power allocation method and a base station using the same. They are applicable to cooperative non-orthogonal multiple access (NOMA) systems. The method includes: sorting K user equipment devices (UEs) according to the K channel gains between the base station and the K UEs, and then establishing a strong user candidate group of K/2 UEs and a weak user candidate group of K/2 UEs; pairing each of the UEs in the strong user candidate group with each of the UEs in the weak user candidate group so as to divide the K UEs into K/2 clusters, where the power allocation coefficients for each pair of UEs are also calculated during the paring process; and transmitting messages to the K UEs based on the calculated power allocation coefficients of the K/2 clusters.

Abstract: A method of joint clustering and precoding and a base station using the same are provided and applicable to a non-orthogonal multiple access (NOMA) system. The method includes: dividing four user equipments into a first cluster and a second cluster each consisting of two user equipments; forming a first cluster signal and a second cluster signal for simultaneous transmission at the base station; establishing a first precoding set and a second precoding set for the first cluster and the second cluster, respectively, by using channel state information between the base station and all the user equipments; selecting a first precoder from the first precoding set and a second precoder from the second precoding set; superposing the first cluster signal multiplied by the first precoder and the second cluster signal multiplied by the second precoder and broadcasting a resulting signal to the user equipments in the first and second cluster.

Abstract: This invention discloses a multicarrier communication system that includes a transmitter equipment and a receiver equipment. According to a timing scheme, the transmitter equipment processes multiple original symbols for transmission on multiple subcarrier channels, and the receiver equipment processes and detects multiple received symbols from the multiple subcarrier channels. During a time frame of data transmission, the initial three of the original symbols for each of the subcarrier channels are three pilot symbols, forming a preamble. The three preambles of every consecutive three of the subcarrier channels form a preamble unit. All the pilot symbols of the preamble unit are expressed as a 3×3 matrix. When the center pilot symbol of the preamble unit is normalized to 1 or j (i.e., the imaginary unit), the matrix is [ - j - j - j j 1 - j - j j - j ] ? ? or ? [ 1 1 1 - 1 j 1 1 - 1 1 ] .

Abstract: The disclosure proposes a method of power allocation and a base station using the method. The method is applicable to a base station for transmitting information signals to at least two user equipments in a non-orthogonal multiple access (NOMA) system. The method includes: setting a first transmit power of a first user equipment to be smaller than a second transmit power of a second user equipment, where a channel gain of the first user equipment is larger than that of the second user equipment; calculating a first system capacity of the first user equipment according to the first transmit power, and calculating a second system capacity of the second user equipment according to the second transmit power; summing the first system capacity and the second system capacity to obtain a sum capacity; and calculating the first transmit power and the second transmit power based on maximizing the sum capacity.

Abstract: Provided is a cooperative multimedia communication system. The source node includes a first hierarchical modulation constellation diagram, modulates two data streams and transmits a first signal and a second signal. The relay node includes a protection-level-exchanging modulation and a second hierarchical modulation constellation diagram, modulates the second signal to generate a third signal and transmits the third signal. The destination node receives the first signal and the third signal and performs optimal decoding. The present disclosure designs a pair of optimal hierarchical constellation diagrams respectively for the source node and the relay node. Moreover, the present disclosure further provides a cooperative multimedia communication method.

Abstract: Provided is a cooperative multimedia communication system. The source node includes a first hierarchical modulation constellation diagram, modulates two data streams and transmits a first signal and a second signal. The relay node includes a protection-level-exchanging modulation and a second hierarchical modulation constellation diagram, modulates the second signal to generate a third signal and transmits the third signal. The destination node receives the first signal and the third signal and performs optimal decoding. The present disclosure designs a pair of optimal hierarchical constellation diagrams respectively for the source node and the relay node. Moreover, the present disclosure further provides a cooperative multimedia communication method.

Abstract: The disclosure proposes a method of power allocation and a base station using the method. The method is applicable to a base station for transmitting information signals to at least two user equipments in a non-orthogonal multiple access (NOMA) system. The method includes: setting a first transmit power of a first user equipment to be smaller than a second transmit power of a second user equipment, where a channel gain of the first user equipment is larger than that of the second user equipment; calculating a first system capacity of the first user equipment according to the first transmit power, and calculating a second system capacity of the second user equipment according to the second transmit power; summing the first system capacity and the second system capacity to obtain a sum capacity; and calculating the first transmit power and the second transmit power based on maximizing the sum capacity.

Abstract: A decoding method for low density parity check (LDPC) code, used to decode an input signal into a correct codeword according to a predetermined LDPC matrix, is provided. The method includes performing a plurality of decoding attempts according to the LDPC matrix within a predetermined number of decoding attempts, the plurality of decoding attempts at least including a first decoding attempt with use of a first decoding schedule and a second decoding attempt with use of a second decoding schedule. The second decoding attempt is adjacently subsequent to the first decoding attempt. The first decoding schedule as a group is not included in the second decoding schedule.

Abstract: An encoding and decoding method of low-density parity-check code is disclosed. The method is following steps: a high rate check code is transferred to a check matrix having a protograph. The check matrix is extended to form an extended base matrix and is split to form a split base matrix. The extended base matrix and the split base matrix are respectively calculated to generate their decoding threshold by a protograph extrinsic information transfer chart. The base matrix with the lower decoding threshold is considered as a low rate base matrix. Repeating the above process until a stop condition is satisfied. The last low rate base matrix is expanded to form a parity check matrix. The transmission data is encoded and decoded by the parity check matrix.

Abstract: This invention provides a relay precoder selection method for two-way amplify-and-forward multiple-input multiple-output (MIMO) relay systems and communication devices using the selection method or the selected relay precoder. According to the relationship between a relay precoder and the singular values of the effective MIMO channels, a set of candidate relay precoders are constructed based on the singular vector subspaces of cascaded MIMO channels, and one of them is selected for meeting a specific design criterion, such as the minimum sum of mean-squared errors, the maximum sum of channel capacities, and the minimum or maximum sum of condition numbers, where the condition number is defined as the ratio of the largest to the smallest singular value of a MIMO channel. As compared with the iterative design methods with the best performance, this invention achieves close performance while requiring much lower computational complexity.

Abstract: A method of joint clustering and precoding and a base station using the same are provided and applicable to a non-orthogonal multiple access (NOMA) system. The method includes: dividing four user equipments into a first cluster and a second cluster each consisting of two user equipments; forming a first cluster signal and a second cluster signal for simultaneous transmission at the base station; establishing a first precoding set and a second precoding set for the first cluster and the second cluster, respectively, by using channel state information between the base station and all the user equipments; selecting a first precoder from the first precoding set and a second precoder from the second precoding set; superposing the first cluster signal multiplied by the first precoder and the second cluster signal multiplied by the second precoder and broadcasting a resulting signal to the user equipments in the first and second cluster.

Abstract: A mounting plate and a security device using the same are provided. The mounting plate is for being fixed to a surface, wherein a mounting device is hanged up on the mounting plate, and the mounting plate comprises a first conductive sheet and a second conductive sheet electrically connected to a first electrode of an exterior power and a second electrode of the exterior power respectively. When the mounting device is hanged up on the mounting plate, the exterior power is electrically connected to the mounting device through the first conductive sheet and the second conductive sheet.