311 results about "Channel allocation schemes" patented technology

In some aspects, each cell in the communications system can be designed to operate in accordance with a set of back-off factors that identify the reductions in peak transmit power levels for the channels associated with the back-off factors. The back-off factors are defined to provide the required power to a large percentage of the users while reducing the amount of interference. In some other aspects, the cells operate using an adaptive reuse scheme that allows the cells to efficiently allocate and reallocate the system resources to reflect changes in the system. A reuse scheme is initially defined and resources are allocated to the cells. During operation, changes in the operating conditions of the system are detected and the reuse scheme is redefined as necessary based on the detected changes. For example, the loading conditions of the cells can be detected, and the resources can be reallocated and/or the reuse scheme can be redefined. In yet other aspects, techniques are provided to efficiency schedule data transmissions and to assign channels to users. Data transmissions can be scheduled based on user priorities, some fairness criteria, system requirements, and other factors. Users are assigned to available channels based on a number of channel assignment schemes. Channel metrics are also provided, which can be used to prioritize users and for channel assignments.

A method of reducing interference in a cellular radio communication including performing a courtesy handover of a first call to another channel to reduce interference in a second call when the presence of the first call on the same frequency as the second call causes the interference in the second call. Also, a method of setting up a call which permits a retry to a macro cell when a channel of sufficient quality is not found in a micro cell.

A method for requesting a Base Station (BS) to assign a sub-channel by a Subscriber Station (SS) in a Broadband Wireless Access (BWA) communication system including the SS and the BS, the BS assigning the sub-channel to the SS by a predetermined scheme. The method includes determining by the SS an assignment scheme of a sub-channel currently assigned to the SS and confirming channel quality indicator of the sub-channel assigned by the determined sub-channel assignment scheme, transmitting, to the BS, a codeword representing a sub-channel assignment scheme to be converted, when the SS determines a need to convert the current sub-channel assignment scheme, and receiving a sub-channel through the converted sub-channel assignment scheme according to the transmitted codeword.

In a Vehicular Ad Hoc Network (VANET) a hybrid method combines SDMA (Space Division Multiple Access) and dynamic TDMA (Time Division Multiple Access) that divides the roadway into regions (whose size is larger than the SDMA unit) where each region is allocated a pool of radio channels based on SDMA and may contain a limited number of vehicles. Vehicles within the same region compete for and access the channels using dynamic TDMA. A channel allocation scheme that maps the pool of channels to the regions such that when a vehicle acquires multiple channels (time slots) in a region, the intervals among the channels are as uniform as possible, thus minimizing the waiting time of the messages to be broadcast by the vehicle, which is critical for safety related applications. This solution is referred to as R-SDMA (Region based SDMA).

A method and apparatus for allocating resources of a Visible Light Communication (VLC) terminal in a VLC system. The VLC terminal receives a beacon message from a base station, coordinates time synchronization with the base station, searches for an available wavelength channel, constructs available wavelength channel information, and transmits an initial access request using a basic time slot channel and a basic wavelength channel. The base station considers the available wavelength channel information and a current channel allocation condition, allocates an appropriate channel, and transmits channel allocation information to the VLC terminal. The VLC terminal and the base station communicate data with each other using an allocated time slot channel included in the channel allocation information and an allocated wavelength channel included in the channel allocation information.

A mobile communication system in which, when transmission is performed from a base station to a terminal device, a modulation scheme is designated, from among at least two modulation schemes with different modulation levels, on the basis of reception quality at the terminal to perform transmission from the base station. The system includes a base station transmitting at a first transmission power using a frequency designed for, in a channel allocation scheme of the system, not causing interference with an adjacent base station and using a first modulation scheme, and a second channel transmitting at a second transmission power lower than the first transmission power, and when the base station uses the second channel, a second modulation scheme having a lower modulation level than the first modulation scheme is designated, and communication is performed.

The invention relates to a physical-layer sub-channel allocation method, an emission system and a receiving system. Physical-layer channels are divided into a plurality of basic channel units on time or time and frequency; the basic channel units transmit data on corresponding divided time or/and frequency fragments; the needed basic channel units for transmitting newly added business are determined according to business demand and are reserved; the reserved basic channel units are merged into a newly added physical layer sub-channel assigned to the newly added business; and after basic business and the newly added business are coded and modulated respectively, the newly added business is transmitted in the newly added physical layer sub-channel, while the basic business is transmitted in the rest of the physical-layer channels. Under the circumstance of guaranteeing the complete compatibility with the prior national standard system, the invention has the advantages of providing the newly added business with enhanced code modulation besides the basic business, reducing the cost and power consumption of receivers and realizing complexity.

The invention discloses a channel distribution method of multi-carrier code division multiple access system, comprising: in each section, selecting one or several frequency points as the main carrier frequency from the distributed frequency points while the left frequency points as auxiliary carrier frequency; according to the priority level, transmitting the downward guide time slot, the broadcast information and the calling information on the main carrier frequency with highest priority and arranging other public control channel on other main carrier frequency; indicating the main carrier frequency of system, so the base station can find the frequency of transmitting broadcast and calling information, and adding the information of frequency points on the all distributed information of all channels; the main and auxiliary carrier frequencies use the same disturbing code and the basic training sequence; operating the multi-time slot arrangement on same carrier frequency; setting the upward-downward switching points of main and auxiliary carrier frequencies as same. The invention can arrange a plurality of main carrier frequencies to provide the public access control channel service and reduce the interface probability and the access time in the accessing time of user terminal.

The invention provides a channel allocation method in wireless mesh network, which uses the radio frequency protection ratio and district traffic intensity as the channel allocation indicator to realize the co-channel multiplexing in a virtual layered Mesh network structure. The channel allocation scheme performs the channel allocating using the district as unit and an extended set T-coloring coloring module is used. The radio frequency protection ratio is used as the indicator of the channel allocation and the channel is multiplexed when the carrier interference is larger than the radio frequency protection ratio. The district diameter is controlled in district separation way when the district traffic intensity is not uniform. The invention provides a wireless channel allocation method for the virtual layered Mesh network structure, therefore the utilization ratio of the wireless frequency spectrum resource is increased and the wireless interference between the districts is reduced.

A channel allocation process for a cellular telephone network starts from a position of homogeneity in which each base station has the potential to use all channels. It develops ever greater heterogeneities by processing a combination of short and medium range interactions between the base stations themselves, causing each base station of the cellular telephone network to inhibit its neighbors from using a given channel, to generate a usage factor for each channel in each cell indicative of the level of interference to be expected on that channel in that cell. Channels can then be allocated to each base station according to the ranking of the usage factors determined for the channels at that base station. The entire network may be emulated by a single processor, controlling the base stations of the network in accordance with the results of the process. Alternatively, each base station of the network performs that part of the process relating to itself, in co-operation with its neighbors, and utilizes channels in accordance with results.

The invention relates to a dynamic spectrum access method with a network cognition ability, belonging to the technical field of wireless communication. The dynamic spectrum access method comprises the following steps of: (1) channel allocation: available spectra are segmented into a series of frequency bands, the frequency bands are different in bandwidth and transmitting ranges, and the frequency bands are channels; each channel is completely orthogonal, and a secondary user can use multiple channels at the same time; when several users use the same channel at the same time within a certain range, conflicts and interference occur; and the positions of all users are permanent; (2) channel access: in a cognitive wireless network, the secondary users fully utilize channels not used by primary users, i.e. the secondary users take full advantage of idle time slots of channels allocated to the primary users; and the primary users using the channels do not take the existence of the secondary users into account by using a second-order Markov Model; and (3) channel switching.

A base station includes an adaptive control unit for obtaining weights (w1′ to w4′) of antenna elements indicating an arrival direction of an interference signal detected on a radio channel that is not being used for communication, and weights (w1 to w4) indicating an arrival direction of a desired signal arriving from a mobile station. The base station further includes an interference signal suppressibility determining unit for determining, based on the weights (w1 to w4) and the weights (w1′ to w4′), whether or not it is possible to form a direction pattern that directs a main beam toward the arrival direction of the desired signal and directs a null toward the arrival direction of the interference signal; and a channel allocation unit for determining, based on a result of the determination, whether to allocate the mobile station the radio channel on which the interference signal is detected.

The invention discloses a data communication method, which comprises the following steps that: when the channel allocation of the base station is changed, the base station sends the changed channel allocation information to a terminal; and the terminal carries out data communication with the base station according to the changed channel allocation information. The data communication method can meet the allocation requirement of dynamically modifying an air interface of the base station and the terminal in the 802.16 protocol, and meet the requirement of smooth switch of the terminal between adjacent base stations.

The invention discloses a method for routing multicasts and allocating frequency spectrums in a cognitive wireless Mesh network, comprising the following steps of: modelling the cognitive wireless Mesh network composed of a static CR-Mesh router into an undirected multi-graph; then, using a genetic algorithm to obtain a channel allocation scheme that a maximum value of path delay is minimum, including initialization; based on a shortest path algorithm, calculating an individual fitness function value; executing selection, crossover and mutation operations; generating the next generation of population; achieving a generation number; and outputting a plurality of steps of an optimal solution. By means of the invention, the problem of routing multicasts and allocating frequency spectrums of a monophyletic node in the cognitive wireless Mesh network can be solved; therefore, the maximum value of the path delay from a source node to all multicast destination nodes is minimum; and the network performance can be effectively improved.

The embodiment of the invention discloses a channel allocation method and a channel allocation device and base station control equipment. The channel allocation method mainly comprises the following steps of: acquiring current idle channel conditions of cells; and determining a channel allocation mode according to accessed service types and the current idle channel conditions of the cells, wherein the accessed service types comprise voice service or data service. By performing the channel allocation according to the service types and the idle channel conditions, the technical scheme disclosed by the embodiment of the invention can make the voice service and data service flexibly use the cell channel resources according to the current idle channel conditions of the cells.