3735 results about "Time-division multiplexing" patented technology

A multi-ladar sensor system is proposed for operating in dense environments where many ladar sensors are transmitting and receiving burst mode light in the same space, as may be typical of an automotive application. The system makes use of several techniques to reduce mutual interference between independently operating ladar sensors. In one embodiment, the individual ladar sensors are each assigned a wavelength of operation, and an optical receive filter for blocking the light transmitted at other wavelengths, an example of wavelength division multiplexing (WDM). Each ladar sensor, or platform, may also be assigned a pulse width selected from a list, and may use a pulse width discriminator circuit to separate pulses of interest from the clutter of other transmitters. Higher level coding, involving pulse sequences and code sequence correlation, may be implemented in a system of code division multiplexing, CDM. A digital processor optimized to execute mathematical operations is described which has a hardware implemented floating point divider, allowing for real time processing of received ladar pulses, and sequences of pulses.

In an OFDM system, a transmitter broadcasts a first TDM pilot on a first set of subbands followed by a second TDM pilot on a second set of subbands in each frame. The subbands in each set are selected from among N total subbands such that (1) an OFDM symbol for the first TDM pilot contains at least S₁ identical pilot-1 sequences of length L₁ and (2) an OFDM symbol for the second TDM pilot contains at least S₂ identical pilot-2 sequences of length L₂, where L₂>L₁, S₁·L₁=N, and S₂·L₂=N. The transmitter may also broadcast an FDM pilot. A receiver processes the first TDM pilot to obtain frame timing (e.g., by performing correlation between different pilot-1 sequences) and further processes the second TDM pilot to obtain symbol timing (e.g., by detecting for the start of a channel impulse response estimate derived from the second TDM pilot).

A system and method for managing the allocation of Time Division Multiplexing (TDM) timeslots in a network switch. The network switch may use a TDM cycle comprising multiple timeslots to manage shared resources and to schedule data ingress and egress through the ports of the current configuration, wherein each port is assigned one or more timeslots. The network switch may be reprogrammed to support one of multiple timeslot assignment schemes for one of multiple port configurations. The network switch may support configurations with varying numbers of ports, e.g. 8- and 16-port configurations. A network switch may also support configurations where two or more ports are combined to form one port, for example, a 2 Gbs Fibre Channel port. To meet the requirements of the various configurations, the timeslot assignment scheme may be reprogrammed to meet the scheduling requirements of each of the possible port configurations.

A method for subcarrier allocation and loading for a multi-carrier, multi-subscriber system is described. At least one cluster in a first and second set of clusters of subcarriers is associated for use in communication with a first and second subscriber, respectively. Then, for each cluster associated for use in communication with the first subscriber and the second subscriber, usage of that cluster is multiplexed between the first subscriber during a first time division and the second subscriber during a second time division.

A method and apparatus for spatial multiplexing and demultiplexing of radio signals. A multichannel transmitter and receiver is integrated in a base station and coupled to an antenna array. Using digital radio signals containing previously known or non-Gaussian sequences and arranged in frames, the spatial information about each mobile unit is estimated on the basis of the signal received by the receiver for the reception and transmission frequencies. This is done by known sequences or by blind source separation methods. The respective paths of each mobile unit with the power above a predetermined threshold is isolated by spatial filtering in the presence of multiple channel paths in order to provide spatial demultiplexing. Simultaneously, the intended signal is transmitted in the direction of the main path of each mobile unit while protecting each mobile unit from signals transmitted in the direction of other mobile units by spatial filtering with cancelling constraints in order to provide spatial multiplexing.

A cellular wireless internet access system which operates in the 2.5 to 2.68 GHz band and which must comply with complex government regulations on power levels, subscriber equipment and interference levels yet which provides high data rates to users and cell sizes of 1½ miles radius or more from base stations with subscriber equipment and antennas mounted indoors. Such base stations are mounted low and use spread-spectrum transmission to comply with interference rules with respect to adjacent license areas. An unidirectional tear-drop coverage pattern is used at multiple cells to further reduce interference when required. Time division duplex is used to allow the system to operate on any single channel of varying bandwidth within the 2.5 to 2.68 GHz band. Backhaul transmission from base stations to the Internet is provided using base station radio equipment, operating either on a different frequency in the band or on the same frequency using a time-division peer-to-peer technique. Different effective data-rates are provided by a prioritization tiering technique.

A method and system for a single chip integrated Bluetooth and FM transceiver and baseband processor are provided. The single chip may comprise a Bluetooth radio, an FM radio, a processor system, and a peripheral transport unit (PTU). FM data may be received and/or transmitted via the FM radio and Bluetooth data may be received and/or transmitted via the Bluetooth radio. The FM radio may receive radio data system (RDS) data. The PTU may support digital and analog interfaces. A processor in the processor system may time-multiplex processing of FM data and processing of Bluetooth data. The single chip may operate in an FM-only, a Bluetooth-only, and an FM-Bluetooth mode. The single chip may reduce power consumption by disabling portions of the Bluetooth radio during FM-only mode and/or disabling analog circuitry when performing digital processing. Communication between Bluetooth and FM channels may be enabled via the single chip.

Provided are a sync channel of a forward link, a common pilot channel structure, and an initial cell search method and an adjacent cell search method for handover in a cellular system using orthogonal frequency division multiplexing (OFDM). A cell search method in an OFDM cellular system in which a primary sync channel and a secondary sync channel are configured based on time division multiplexing (TDM) includes acquiring sync block synchronization and a primary sync channel sequence number using a primary sync channel symbol included in a frame received by a terminal, detecting a boundary of the frame and a scrambling code group using the sync block and a secondary sync channel symbol included in the frame received by the terminal, and acquiring a scrambling code using the primary sync channel sequence number and the scrambling code group, thereby reducing cell search time with low complexity.

A base station includes a scheduler configured to perform frequency scheduling for each subframe; a control channel generating unit configured to generate a control channel including common control information to be mapped to radio resources distributed across a system frequency band and specific control information to be mapped to one or more resource blocks allocated to each selected user device; and a transmission signal generating unit configured to generate a transmission signal by time-division-multiplexing the common control information and the specific control information according to scheduling information from the scheduler. The common control information includes a format indicator representing one of preset options that indicates the number of symbols occupied by the common control information in one subframe. The common control information includes information units with a predetermined data size. The number of the information units is less than or equal to a specified multiplicity included in broadcast information.

A portable programming device is used in a supervisory remote control system comprising a signal transmission unit for supplying a signal according to a TDM (Time Division Multiplexing) manner, first and second terminals having individual addresses, and a signal line connecting therebetween. According to a set of relation data including an address correspondence between one of the second terminals and one of the first terminals and control data including control parameters of a load, the load connected to the one of the second terminals can be controlled according to a supervisory input provided to the one of the first terminals. The programming device has a hand-held type housing for accommodating a display, operation unit for programming an address, the relation data and the control data, data memory, and a signal processor for transferring the address to a required one of the first and second terminals, and transferring the relation data and the control data stored in the data memory to the transmission unit. The signal processor further comprises a data retrieving unit for retrieving at least one set of the relation data and the control data corresponding to an address designated by the operation unit from the transmission unit, and listing a name given to the set on the display.

A method for determining the radio frame structure of a Time Division Duplex system is disclosed, which comprises: configuring, by the network side, the radio frame structure used for service transmission as containing two half-frames each of 5 ms, wherein each half-frame consists of eight service time slots of 0.5 ms and one special time slot field of 1 ms, two consecutive service time slots form a subframe of which the length is 1 ms, and the special time slot field contains a DwPTS, a GP and an UpPTS; determining the lengths of the DwPTS, the GP and the UpPTS in the special time slot field according to the requirements of the coverage range, and determining the radio frame structure used for service transmission. By reconfiguring the radio frame structure, the invention can flexibly support different coverage ranges, enhance the flexibility of satisfying different service requirements, and implement the coexistence of two types of TDD systems.

A point-to-multipoint passive optical network transmits downstream data from an optical line terminal (OLT) to multiple optical network units (ONUs) in variable-length packets and upstream data from the ONUs to the OLT in variable-length packets utilizing time division multiplexing to avoid transmission collisions. In an embodiment, the variable-length downstream packets and the variable-length upstream packets are formatted according to IEEE 802.3. In an embodiment, the length of the variable-length downstream and upstream packets is related to the length of Internet protocol (IP) datagrams carried within the packets.

A data transmission system uses a method of aligning a plurality of transmission lanes with a plurality of reception lanes in a time-division multiplexing arrangement. The method utilizes a plurality of control symbols and lane identifiers that are transmitted on each of the transmission lanes during link initialization and training. The control symbols and lane identifiers are time-division multiplexed onto a data link and subsequently demultiplexed onto the plurality of reception lanes. One of the reception lanes is monitored for receipt of a control symbol followed by a lane identifier. Upon receipt, a lane identifier is compared to the identity of the reception lane being monitored. If the received lane identifier does not match the identity of the reception lane being monitored, the assignment of the reception lanes is rotated.