Abstract: A beam pattern design method is adapted to an antenna array system. An antenna array of the antenna array system includes a plurality of antenna devices. The beam pattern design method includes the following procedures. A plurality of first virtual beamforming vectors having a first resolution are set. Each of the plurality of first virtual beamforming vectors corresponds to all the antenna devices in the antenna array. Corresponding weights are respectively assigned to phases of the plurality of first virtual beamforming vectors to generate a plurality of correspondingly weighted first virtual beamforming vectors. The plurality of correspondingly weighted first virtual beamforming vectors are linearly combined to synthesize a provisional vector having a second resolution. The phase of each element in the provisional vector is extracted, and a fixed amplitude is provided to the extracted phase of each element in the provisional vector to generate a final beamforming vector.

Abstract: A beam alignment method for an antenna array is provided. In the method, a base station uses multi-modal beam patterns for transmitting several synchronization signals. User equipment scans the synchronization signals, determines a synchronization signal with the strongest received power and a receive beam direction corresponding thereto, and transmits an initial access message including index information indicating the strongest synchronization signal.

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: A communication method of coordinated multi-point transmission systems. Based on the Zadoff-Chu sequences, multiple training sequences are implemented, and the training sequences are a set of robust orthogonal training sequence (ROTS). Preamble signals that use the set of training sequences can be transmitted from multiple base stations/relay stations at the same time. In the case with the mixture signal of multiple preamble signals, user equipment can still use the received signal to estimate multiple carrier frequency offsets of the corresponding base stations/relay stations.

Abstract: A communication method for estimating Doppler spread includes the following steps: transmitting a preamble signal to a receiver from a transmitter of a transmission terminal. The preamble signal is received by the receiver; followed by dividing the received samples in the preamble signal into a plurality of sets of samples. The plurality of sets of samples are introduced into a Doppler spread estimation algorithm to estimate Doppler spread.

Abstract: A communication method of coordinated multi-point transmission systems. Based on the Zadoff-Chu sequences, multiple training sequences are implemented, and the training sequences are a set of robust orthogonal training sequence (ROTS). Preamble signals that use the set of training sequences can be transmitted from multiple base stations/relay stations at the same time. In the case with the mixture signal of multiple preamble signals, user equipment can still use the received signal to estimate multiple carrier frequency offsets of the corresponding base stations/relay stations.

Abstract: A multi-class multimedia broadcast/multicast service (MBMS) system includes a transmitter and at least one receiver. The transmitter transmits N primary signals by N primary channels and an auxiliary signal by an auxiliary channel, wherein a resolution of the auxiliary signal is identical to the highest resolution of the N primary signals and the constellation mappings of the auxiliary signal and the primary signal with the highest resolution among said N primary signals on the corresponding modulation constellations are coupled. The receiver couples the primary signal with the corresponding auxiliary/virtual auxiliary signal to obtain a lower-resolution virtual auxiliary signal, which can also be coupled with the primary signal having the same resolution. Therefore, receiving quality of each resolution is improved by combining the primary signal and the corresponding auxiliary/virtual auxiliary signal.

Abstract: A multi-class multimedia broadcast/multicast service (MBMS) system includes a transmitter and at least one receiver. The transmitter transmits N primary signals by N primary channels and an auxiliary signal by an auxiliary channel, wherein a resolution of the auxiliary signal is identical to a resolution of the primary signal with the highest resolution and the constellation mappings of the auxiliary signal and the primary signal with the highest resolution on the corresponding modulation constellations can be coupled. The receiver couples the primary signal with the corresponding auxiliary/virtual auxiliary signal to obtain a lower-resolution virtual auxiliary signal, which can also be coupled with the primary signal having the same resolution. Therefore, receiving quality of each resolution is improved by combining the primary signal and the corresponding auxiliary/virtual auxiliary signal.