Abstract: The invention discloses a wireless communication system for calculating time of flight. The system transmits and receives a plurality of packets every a plurality of delay times. Thereafter, the wireless communication system calculates a plurality of reference times according to the delay times and processing times and then averages the reference times to obtain the time of flight. Thereby, the time of flight can be calculated more accurately.

Abstract: A computer apparatus comprises a CPU, power supply unit, and low power-consuming detection device for wireless transmission ability. The power supply unit supplies a detection-device power as a detection event is triggered ; and a system power to the CPU as a power-on event is triggered. The detection device detects transmission ability of wireless communication connection of the computer apparatus in response to the detection device power. The detection device comprises a signal processing unit, an embedded low-power processor and a display unit. The signal processing unit receives a RF signal via the wireless communication connection and demodulating the RF signal to generate transmission data. The embedded low-power processor calculates dynamic data amount information, dynamic data flux information or dynamic transmission quality information of the wireless communication connection in response to the transmission data. The display unit is for displaying the above information.

Abstract: An adaptive channel estimator for estimating channel frequency responses when receiving OFDM symbols. The adaptive channel estimator comprises a channel estimator and a channel tracking module. The channel estimator generates one first channel frequency response for each OFDM symbol when operated in the first mode, and generates the channel frequency responses of a second channel frequency response for every N-th OFDM symbols when operated in the second mode, wherein N is a constant integer exceeding one and j is a non-negative integer. The channel tracking module indicates a channel status, and controls the channel estimator to operate in a first mode or a second mode according to the channel status.

Abstract: A guard section length detection method is disclosed. In the method, a guard section length detection method is used in an OFDM system. The OFDM symbol includes a data interval having a first length, and a guard section having a guard section length. The method detects a first symbol boundary and a second symbol boundary, and determines the guard section length based on a length between the first symbol boundary and the second symbol boundary.

Abstract: A method for authenticating user terminal in IMS network, the method includes: with regard to user request, Service-Call Session Control Function (S-CSCF) entity creates the authentication challenge utilizing Digest Authentication Algorithm, and sends the authentication challenge to user terminal through Proxy-Call Session Control Function (P-CSCF) entity; the user terminal creates the authentication response utilizing Digest Authentication Algorithm according to the user key and associated parameters with said authentication challenge, and sends the authentication response to S-CSCF entity through S-CSCF entity; S-CSCF entity authenticates said authentication response utilizing Digest Authentication Algorithm according to HA1 and associated parameters, if the authentication passes, determines that the user terminal is authenticated successfully, otherwise, determines that the user terminal is authenticated failure.

Abstract: A guard section length detection method detects whether a preamble signal is received. A short preamble boundary is then detected, then detecting a frame boundary and detecting a guard section length. In the step of detecting the guard section length a second matched filter capable of processing 128 point data sets is detected. Four different 128 point data sets have a distance of 8 points, 16 points, 32 points, and 64 points respectively from the frame boundary to the second matched filter. Four signal correlation values are calculated for determining the guard section length.

Abstract: A method and system is disclosed for enabling number portability in a communication session between a caller and a callee in an IMS network. When a caller or callee changes her subscription from a first network to a second network, mechanisms are implemented to have the number portability information provided so that the moved caller or callee can still engage in communication sessions using her original public identification number.

Abstract: The present invention provides an antenna-array-based multiple-input multiple-output orthogonal-frequency-division-multiplexing (MIMO-OFDM) system and a pre-coding and feedback method used in the same. The present invention uses QR decompositions of the MIMO channel matrixes to parameterize the channel state information (CSI) of every OFDM frequency band. In addition, the present invention feeds back the information related to ? and ? in the Givens rotation matrixes of the partial frequency bands and then uses an interpolation method to generate ? and ? in the Givens rotation matrixes of all the frequency bands, which further is able to represent the CSI of all the frequency bands. In this way, the present invention has advantages of low complexity and low feedback rate requirement.

Abstract: The invention provides a method for adjusting a speed-detection device for an object lens in an optical pickup head. The invention provides an adjusted optical disc drive, wherein the optical pickup head is accelerated/decelerated and the speed-detection device outputs a standard signal level. Next, the optical pickup head of an unadjusted optical disc drive is accelerated/decelerated under the same condition, and the speed-detection device outputs a speed signal level. Finally, the gain of a programmable gain amplifier is adjusted until the speed signal is equal to the standard signal.

Abstract: The invention provides a method for adjusting a speed-detection device for an object lens in an optical pickup head. The invention provides an adjusted optical disc drive, wherein the optical pickup head is accelerated/decelerated and the speed-detection device outputs a standard signal level. Next, the optical pickup head of an unadjusted optical disc drive is accelerated/decelerated under the same condition, and the speed-detection device outputs a speed signal level. Finally, the gain of a programmable gain amplifier is adjusted until the speed signal is equal to the standard signal.

Abstract: A collapsible scooter has a frame plate secured on a head tube of the scooter, a strut having a lower end thereof pivotally connected to a foot board of the scooter and an upper end thereof pivotally connected to the frame plate. Opposite sides of the frame plate are symmetrically defined with two pivot slots, the upper end of the strut is pivotally connected with the frame plate and movable along the pivot slots between an upper position in which the scooter is fully collapsed and a lower position in which the head tube is uprightly extended. A retaining device is particularly provided in the scooter to prohibit the head tube from any inadvertent movement relative to the foot board, even when the head tube is subjected to excessive stress during riding on a rough road.