136 results about "Statistical time division multiplexing" patented technology

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.

The invention discloses a method and a system for time division multiplexing of transmitting channels to overcome the defect of lack of using transmitting channel redundancy in a multi-antenna system to reduce transmitting channels. The method includes: using a first group of transmitting channels on a first frequency band to transmit signals to a first geographic region through a first group of antenna units according to a first channel bandwidth in a first time interval; and using the first group of transmitting channels on a second frequency band to transmit signals in a second time interval after the first time interval, or using the first group of transmitting channels on a third group of antenna units to transmit signals, wherein the pass band width of the first channel is smaller than or equal to the width of the first frequency band, and the second frequency band is not identical to the first frequency band. By means of time division multiplexing of transmitting channels among different frequency bands and/or different antenna units, the defect of lack of using transmitting channel redundancy in the multi-antenna system to reduce the transmitting channels in the prior art is overcome.

A time division multiplex transmission system transmits information on multiple channels by using a transmission path with variable time division multiplexing. The variable time division multiplex transmission system of this invention is equipped with multiple channel devices 30 and a single transmission path 5 connected to these multiple channel devices. The multiple channel devices 30 transmit or receive data over the transmission path. Additionally, the system is equipped with a circuit that determines consecutive time slots for using the transmission path, and each of the channel devices transmits or receives data using consecutive time slots. Data can be transmitted in two or more different transmission bands, and the different transmission bands are realized by making the number of time slots used for a communication frame different.

The invention provides a transmission method for uplink control signaling and a base station and user equipment which are used for realizing the same. In the invention, an uplink control channel is divided by at least one of code division multiplexing, time division multiplexing and frequency division multiplexing into one or more of sub-channels for supporting different feedback quantities of uplink control signaling, so that a plurality of sets of user equipment with the same or different uplink control signaling feedback needs can be multiplexed to a time-frequency resource corresponding to the same uplink control channel flexibly. The base station indicates the user equipment dynamically by downlink control channels or semi-statically by high-level signaling to adopt feedback resources of different uplink control channels. When the method, the base station and the user equipment are used, the using efficiency of the uplink control channels can be improved to save loads of the uplink control channels, and the technology of carrier aggregation, collaborative multipoint sending/receiving and multi-antenna enhancement can be supported effectively.

The invention provides a method for indicating sub-frame property in a time division multiplexing (TDD) system of a long-term evolution (LTE) network. The MBSFN indication bits are written in the message SI-1 of system information of system broadcast message of multi-broadcast/broadcast MBSFN frames on each single-frequency network of an improved E-Universal Terrestrial Radio Access Network; and the MBSFN indication bit is used for indicating whether the sub-frame of the MBSFN frame of the LTE TDD is an MBSFN sub-frame. The method indicates whether each sub-frame of the wireless frame adopts the MBSFN by allocating the MBSFN indication bit at the SI-1 of each MBSFN frame in the TDD system of the LTE, thus leading the UE to adopt the MBSFN reference signal or the reference signal specially used by the district on each sub-frame to carry out channel estimation.

The invention discloses an optical fiber wireless RoF passive optical network realizing method based on an optical code division multiplexing (OCDM). In an optical line terminal (OLT) RoF center station, a signal realizes double-sideband modulation, three paths of generated carrier components are respectively modulated with wired and wireless user data and are not subjected to modulation. The signal is coupled to an optical fiber channel after coded by the OCDM, transmitted to an optical distribution network (ODN) and allocated to each optical network unit (ONU). The ONU carries out OCDM decoding on the received signal, then three paths of components are separated, one path of components is directly sent to a wired user terminal after subjected to photoelectric detection, the other two paths of components enter an RoF base station for carrying out beat frequency to obtain a radio frequency signal, the radio frequency signal is subjected to ECDMA (Electric Code Division Multiple Access) coding and transmitted through an antenna after subjected to electric amplification, and a wireless user terminal obtains a required signal through ECDMA decoding. The invention provides an effective path for realizing wired/wireless secrecy access in a PON (Passive Optical Network) system.

The invention provides a self-adaptive switching method of space division multiplexing and code division multiplexing for a time division synchronous code division multiple access system. One method comprises the following steps: S102, estimating an uplink channel by a node B, and real-timely evaluating the mutual relativity of the space channels of two transmission blocks according to the estimation result; S104, switching to the code division multiplexing mode when the mutual relativity of the space channels is larger than a first threshold, and carrying out throughput evaluation when the mutual relativity of the space channels is smaller than the first threshold; S106, respectively estimating the throughput of the space division multiplexing mode and the code division multiplexing mode by the node B according to the channel quality of the space division multiplexing mode or the code division multiplexing mode fed back by a user terminal, and switching to the space division multiplexing mode if the total throughput of the space division multiplexing mode is larger than a second threshold more than the throughput of the code division multiplexing mode, otherwise, switching to the code division multiplexing mode; and S108, informing the user terminal of the multiplexing mode adopted by the subsequent downlink service channel and the related information by the node B through a downlink control channel.

The invention discloses a time division multiplexing (TDM)-based low-reflectivity triangle spectrum-shaped fiber grating sensing system. The system mainly comprises a distribution feedback laser, an electro-optical modulator, a circulator, an optical amplifier, a triangle spectrum-shaped fiber grating sensor, a high-speed optical detector, a pulse signal generator and a signal acquisition device, wherein the distribution feedback laser is used for emitting narrow line-width laser; pulse signal light is formed by the narrow line-width laser through the electro-optical modulator or is generated by internal modulation through the distribution feedback laser; the pulse light passes through the circulator and then is reflected by a triangle spectrum-shaped fiber grating; the reflected light passes through the circulator to enter the optical amplifier and is amplified into the high-speed optical detector; and a light signal is converted into an electrical signal through the high-speed optical detector, and the electrical signal is converted into a digital signal and is processed through the signal acquisition device. In the system, the distribution feedback laser and the low-reflectivity triangle spectrum-shaped fiber grating sensor are combined, a large-scale fiber grating sensing network is constructed through TDM, and thousands of sensors are multiplexed on a single fiber, so that the costs of a light source and a wavelength detection device are reduced.

A time-spreading and wavelength-hopping optical encoder spreads each pulse in a modulated optical pulse signal into a predetermined pulse train including pulses with different wavelengths. The last pulse in the pulse train is delayed from the first pulse in the pulse train by an interval that is longer than the pulse period of the modulated optical pulse signal. Interference is avoided by dividing the pulse train into successive delay groups that are equal in length to the pulse period of the modulated data pulse signal, and having each wavelength appear in only one delay group. If encoders producing differently structured pulse trains are used in an optical multiplexer, interference is avoided by having the same wavelength appear only at different positions within the delay groups of different pulse trains. Long delays can be used to multiplex a relatively large number of channels, even at high transmission rates.

A precoding-multiplexing circuit is formed by a precoding circuit for carrying out a precoding with respect to n sets of parallel input binary data signals having a bit rate equal to R/n, to obtain n sets of parallel precoded signals, and a time division multiplexer for time division multiplexing the parallel precoded signals obtained by the precoding circuit, in units of one bit, and outputting time division multiplexed output signal having a bit rate equal to R. In this configuration, the encoding is realized by processing electric signals before the time division multiplexing, so that it becomes possible for the preceding circuit to handle signals which are slower than the transmission rate, and therefore it becomes easier to realize the higher transmission rate.

The invention provides a method and a device for transmitting a time division multiplex (TDM) service. The method comprises the following steps of: encapsulating a predetermined TDM frame signal of a first TDM network side into a grouped data packet; and transmitting the grouped data packet to a packet switching network. Due to the adoption of the method and the device, certain channels and certain time slots in the TDM frame signal can be selectively loaded to a data packet so that the bandwidth utilization ratio of the network can be increased.

A ML simplified detecting method of space division multiplexing in multi-input/multi-output antenna system includes finding out a sending antenna with maximum modulation system when channel parameter is known, carrying out ML exhaustion search on modulation constellation of the other sending antenna then subtracting influence of these antenna signals in received signal and using IF algorithm to demodulate antenna with maximum modulation system, corresponding each ML exhaustion search to one IF demodulation result, finding out an optimum combination and using it as demodulation signal of sending antenna.

A novel power automatic information transmission platform comprises an EPON. The EPON mainly comprises an OLT, an ODN and a user ONU. The novel power automatic information transmission platform overcomes the defects in the prior art and has the advantages that construction, operation and maintenance cost is saved; due to the fact that only passive devices such as an optical fiber and an optical branching device are arranged between the OLT and the ONU, a machine room and a power device do not need to be rented, active devices are not needed, and maintenance staff are reduced; rich bandwidth resources are achieved, namely, the kilomega rate is adopted on both the uplink and the downlink of the EPON, and dynamic bandwidths can be flexibly distributed according to user requirements; the point-to-multipoint structure is adopted, so that convenience is brought for system expansion and updating; the functions of simultaneous transmission and time division multiplexing, IP data and videos and other services are possessed; optical fiber communication is adopted in the whole process, so that the anti-interference capacity is extremely high.

Methods and apparatus for interrogating sets of optical elements having characteristic wavelengths spanning a sweep range while avoiding overlapping reflections from the different sets when performing a wavelength sweep are provided. One example method generally includes introducing a pulse of light, by an optical source, into an optical waveguide to interrogate at least first and second sets of optical elements, wherein the optical elements within each set have different characteristic wavelengths and wherein the first and second sets are separated in time such that a first time window over which light is reflected from the optical elements in the first set and reaches a receiver does not overlap with a second time window over which light is reflected from the optical elements in the second set and reaches the receiver; and processing the reflected light to determine one or more parameters corresponding to the optical elements.

Provided are an Optical Network Unit (ONU) for low latency packet transmission in a Time Division Multiplexing-Passive Optical Network (TDM-PON), a method of operating the ONU, and an apparatus for controlling the ONU. The method includes: receiving, from a base station, first bandwidth allocation information regarding a bandwidth allocated by the base station to a terminal for uplink packet transmission; and transmitting a bandwidth allocation request, which is based on the received first bandwidth allocation information, to an Optical Line Terminal (OLT) before completing packet reception from the base station.

Apparatuses and methodologies are described that enhance performance in a wireless communication system using beamforming transmissions. According to one aspect, the channel quality is monitored. Channel quality indicators can be used to select a scheduling technique, such as space division multiplexing (SDM), multiple-input multiple output (MIMO) transmission and opportunistic beamforming for one or more user devices. In addition, the CQI can be used to determine the appropriate beam assignment or to update the beam pattern.