Abstract: The present invention relates to communication technologies and provides a private network communication terminal and a method for realizing private network communication, In the invention, one private network communication can only be performed in one time slot with a fixed location in a DMR TDMA frame, so that other mobile communication terminals that do not participate in the private network communication can determine an unoccupied time slot in advance, thereby they can initiate a new private network communication with the unoccupied time slot.

Abstract: A method and system for decoding SACCH control channels in GSM-based systems with partial combining using weighted SNR may comprise combining least one weighted bit of a GSM slow associated control channel (SACCH) frame with at least one weighted bit of a subsequent GSM SACCH block based on burst signal to noise ratios (SNRs) of the GSM SACCH block and the subsequent GSM SACCH block. The burst SNR may be determined from a mid-amble of the GSM SACCH block and its subsequent GSM SACCH block. The burst SNRs of the GSM SACCH block may be translated to a corresponding plurality of scaling factors. At least a first weighting factor may be determined from the corresponding plurality of scaling factors. At least one weighted bit of the GSM SACCH block is determined utilizing the determined first weighting factor.

Abstract: An embodiment of the present invention provides a method of neighbor discovery in a wireless personal area network, comprising coordinating communications in the WPAN by a WPAN coordinator, and transmitting beacons by the WPAN coordinator on a control channel of the WPAN that specifies the time slots and the order in which devices operating in the WPAN transmit their omni-directional training sequences on a data channel at the beginning of the next super-frame.

Abstract: A base station with multiple antennas including a relay scheduler to select a serving relay from a plurality of candidate relays. Each candidate relay may have a user group including at least one user. The selection may be based on an achievable transmission capacity of each candidate relay with respect to its user group and a state of channels formed between the plurality of candidate relays and the base station. The base station also includes a transmission signal generator to generate a transmission signal for the user group corresponding to the serving relay.

Abstract: A method and wireless multi-cell communication system for providing high speed downlink packet access (HSDPA) services. The system includes a radio network controller (RNC) in communication with a plurality of base stations. The RNC sends a control signal to at least one base station having a plurality of timeslots, e.g., in a time division duplex (TDD) system and/or frames including transmission timing intervals (TTIs), e.g., in a frequency division duplex (FDD) system assigned thereto for the establishment of HSDPA channels. The control signal indicates a maximum allowed HSDPA transmit power for each of the timeslots and/or TTIs. The base station sends a feedback signal to the RNC indicating the results of measurements of the power of the transmitted HSDPA timeslots and/or TTIs during a predetermined time period.

Abstract: The present patent application improves DARP by allowing multiple users on one time slot (MUROS). It comprises means and instructions for sharing signals on a single channel, comprising setting up a new connection, allocating a new time slot if there is an unused time slot on a channel frequency, selecting an used time slot for the new connection to share with an existing connection if there is not an unused time slot on the channel frequency, and selecting a different training sequence code for the new connection if the used time slot on the channel frequency has been selected for the new connection to share with an existing connection.

Abstract: A method, medium, and wireless system are provided for scheduling access terminals to prevent starvation of other access terminals connected to a communication network. The wireless system includes access terminals and base stations that are configured with a first wireless scheduler and a parallel wireless scheduler that select access terminals to communicate during specified time slots. The access terminals may measure channel conditions associated with communications to the base station and transmit requests that specify a desired communication rate to the base station. The first and parallel wireless schedulers on each base station receive the requests from each access terminal and select an access terminal to communicate during a subsequent time slot that may be based on, for example, the channel conditions and weighted average functions of the communication rates—corresponding to the access terminal—generated by the first and parallel wireless schedulers.

Abstract: A femtocell is provided. The femtocell comprises a processor, a memory, and a radio transceiver to communicate with a mobile communication device using a wireless cellular communication protocol and to communicate with the mobile communication device in a data session using one of evolution-data optimized (EV-DO), one times radio transmission technology (1x-RTT), high-speed downlink packet access (HSDPA), worldwide interoperability for microwave access (WiMAX), long-term evolution (LTE). The femtocell also comprises an application stored in the memory that, when executed by the processor, receives simple service discovery protocol messages from a media local area network identifying content stored in the media local area network and provides information about the content to the mobile communication device.

Abstract: A system for transmitting packets over a network of communication channels, the system comprising a set of nodes comprising at least first and second nodes and a network access coordinator operative to coordinate the access of the set of nodes to a synchronous network of channels, wherein, if at least one individual packet has been transmitted from the first node to the second node which did not receive at least one packet, the second node is operative to send a retransmission request to the network access coordinator requesting retransmission of at least one individual packet.

Abstract: A communication method for reducing Radio Resource Control (RRC) connection setup time in an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) includes the step of using an inclusive Signalling Radio Bearer (iSRB) in place of a plurality of individual Signalling Radio Bearers (indSRBs) for transferring signals from Radio Resource Control (RRC) to Medium Access Control (MAC). A Protocol Discriminator (PD) is added to the tail (right side) of each indSRB at the RRC for allowing the MAC to identify each indSRB as received in the iSRB. The PD is needed because the MAC would otherwise be unable to place each indSRB into the appropriate prioritizing queue for trans-mission to the physical layer. The PD is stripped off at the MAC. A preferred embodiment uses the iSRB in place of four individual indSRBs (SRB1, SRB2, SRB3 and SRB4), but in an alternative form the Unacknowledged Mode SRB (SRBI) would not be present in the system and therefore not included in the iSRB.

Abstract: In embodiments, an adaptive tone erasure technique is applied to orthogonal frequency division multiplexing (OFDM) communications, such as ECMA-368 standard ultra-wideband (UWB) communications. A transmitter obtains jammed sub-carrier information and calculates an erasure mask. The jammed sub-carriers are nulled before transmitting to a receiver. In accordance with the erasure mask, bits falling on the jammed sub-carriers are replaced by erasure bits before interleaving, keeping the interleaver block size constant notwithstanding variations in the number of the jammed sub-carriers. The receiver also obtains the jammed sub-carrier information and the erasure mask. After the receiver deinterleaves the constant size blocks, it decodes the data without the erasure bits. The transmitter may detect the jammed sub-carriers itself, or obtain the information from the receiver. The receiver similarly may detect the jammed sub-carriers itself, or obtain the information from the transmitter.

Abstract: A method for realizing forward channel sharing in time division communication system, which completes group configuration at the cluster control service center server and modifies the attributes of all the users to enable the users to support multi-user packet MUP service, including: (a) the cluster user initiates a group call; the access network allocates a unique group identifier MACIndex for the group call after receiving the call request from the calling cluster user and informs all of the users within the group about this MACIndex (201); (b) after the communication starts (202), the access network packets the user data of one or more groups with multi-user packet MUP, packets the user data of each group into one sub-packet and does scheduling, then transmits the packets through forward channel (203); (c) after receiving the MUP packets from the forward channel, the cluster user looks into the MUP packets for the sub-packet that matches the MACIndex of its group, thereby realizing group communication (204

Abstract: A method of an uplink transfer at the UE side in a wireless communications system over a wireless interface between a radio network and a user equipment node uses a first mode of transfer and a second mode of transfer. The first mode of transfer involves sending a first message by the UE to a Node B of the wireless communication system. The second mode of transfer involves receiving a resource by the UE from the Node B, and sending at least one subsequent message by the UE to the Node B, the at least one subsequent message omits an UE id.

Abstract: A method of scheduling data transmissions from a source to a destination, includes the steps of: providing a communication system having a number of channels and a number of paths, each of the channels having a plurality of designated time slots; receiving two or more data transmission requests; provisioning the transmission of the data; receiving data corresponding to at least one of the two or more data transmission requests; waiting until an earliest requested start time Ts; allocating at the current time each of the two or more data transmission requests; transmitting the data; and repeating the steps of waiting, allocating, and transmitting until each of the two or more data transmission requests that have been provisioned for a transmission of data is satisfied. A system to perform the method of scheduling data transmissions is also described.

Abstract: Chase combining gains for receiving a scrambled broadcast channel can be achieved even when a portion of each received channel coded transmission contains a portion that varies. A set of possible difference values for this varying portion, such as for a system frame number, provides hypotheses, each having a corresponding probability. One or more of the hypotheses are selected by rank order for adjusting a corresponding received coded transmission so that two or more channel coded transmissions can be combined and blind decoded until one of the hypotheses are confirmed.

Abstract: A wireless communication apparatus includes a first module, a second module, an inhibit module, a calculation module, and a control module. The first module constitutes a first system. The first system transmits and receives first data to and from a first device. The second module constitutes a second system. The second system transmits and receives second data to and from a second device in each interval time-divided with determined transmission timing. The inhibit module generates inhibit periods for preventing the first module from communicating by use of the first data. The calculation module calculates an occupation time required for the transmission and reception of the first data. The control module compares the period between the inhibit periods adjacent to one another with the occupation time and, according to the comparison result, instructs the first device to stop or delay the transmission of the first data.

Abstract: A multiplexing card comprises a primary TDM port over which TDM frames are communicated to and from a networking device, a plurality of secondary TDM ports over each of which fractional TDM frames are communicated to and from a plurality of digital subscriber line (DSL) units; and a logic device coupled between the primary TDM port and the plurality of secondary TDM ports, wherein the logic device is operable to map timeslots from each of the fractional TDM frames received over the plurality of secondary TDM ports to timeslots in a TDM frame communicated over the primary TDM port, and to map each of a plurality of blocks of timeslots in a TDM frame received over the primary TDM port to one of the plurality of secondary TDM ports; wherein the combined number of timeslots containing user data in the fractional TDM frames received over the plurality of secondary TDM ports is less than or equal to the maximum number of available timeslots in the corresponding TDM frame communicated over the primary TDM port.

Abstract: A method of transmitting data, whereby the data is transmitted by using a multiple access frame divided in logical slots. Each data packet is divided into k units which are decoded by an (n,k) decoder, producing n?k redundant units. The n units are transmitted within a multiple access frame in n different slots according to a time-hopping pattern, a frequency-hopping pattern or a combination of both. At the receiver side lost or corrupted data packets are recovered by using the redundant units, whereby the presence of a unit for each slot is detected. If a unit is present in a slot and has been transmitted without collisions, this unit is recovered. If a sufficient k+? amount of units composing a data packet is recovered, the packet level decoder is used to recover the remaining n?k?? units which experienced collisions in the respective slots.

Abstract: A distributed channel hopping communication method in a low power wireless ad-hoc network. A beacon transmission and reception scheduling method using a distributed channel hopping method in a wireless ad-hoc network, the method includes: transmitting beacons using channel hopping, before establishing the wireless ad-hoc network including a plurality of nodes having a BP including at least one time slot, and receiving beacons of a plurality of neighboring nodes of each of the plurality of nodes; collecting information about the wireless ad-hoc network and information about the plurality of neighboring nodes from the received beacons; scheduling the receiving of the beacons that are transmitted from the plurality of neighboring nodes in the BP, using TDMA in each of the at least one time slot based on the information about the plurality of neighboring nodes; and scheduling transmitting of a beacon in each of the at least one time slot.

Abstract: A communication system for propagating time division multiplexing (TDM) fault notifications has a first interworking function (IWF) of a packet network and a second IWF of the packet network. The second IWF detects a TDM fault of a TDM network and transmits continuity check messages (CCMs) to the first IWF. Further, the second IWF controls the CCMs in response to a detection of the TDM fault such that a TDM fault notification is propagated from the second IWF to the first IWF based on the CCMs, and the first IWF propagates the TDM fault notification to a second TDM node via a TDM signal.

Abstract: A method for minimizing undesired signal coupling from digital interface between peripherals is presented. The method includes transmitting over the interface first and second signals having a parameter ?k set by a dynamic sequencer respectively to a first and second value ?1 and ?2, receiving the first and second signal and generating a first and second interference metric respectively for the first and second signal. The first and second interference metrics are correlated to generate a final parameter value ?f, and a transmitter is then configured to transmit a third signal over the interface with the final parameter value ?f.

Abstract: A system includes at least one adaptive filter coupled to a first communication channel and at least one other communications channel. The at least one adaptive filter includes at least one set of adaptive filter coefficients. A memory stores at least one predetermined set of filter coefficient thresholds. The filter coefficient thresholds may be indicative of channel faults, channel to channel faults or a length of the channel. A controller is configured to compare the set of filter coefficients to the predetermined set of filter coefficient thresholds. The controller is configured to determine the information about the channels based on compare results.

Abstract: When a new call occurs to or from the mobile station capable of treating a plurality of calls simultaneously, the mobile station uses the same branch structure and the same communication frequency band for all of calls. Additionally, when a new call occurs to or from the mobile station capable of treating a plurality of calls simultaneously, a branch structure and a communication frequency band, which can continue all of the calls, are selected and used.

Abstract: A transmitter includes a power measurement unit, a carrier sense unit, and a transmission unit. A first frequency band is allocated to a TDMA system. The power measurement unit measures a receiving power over a part of a first frequency band and a second frequency band. The carrier sense unit continues to check for a certain duration whether the receiving power is smaller than a threshold. The transmission unit generates a transmission signal including a dummy signal and a data signal when the receiving power has been smaller than the threshold for the certain duration. Moreover, the transmission unit transmits the transmission signal using the second frequency band.

Abstract: The present invention employs hierarchical modulation to simultaneously transmit information on different modulation layers using a carrier RF signal. Initially, first data to be transmitted is assigned to a first modulation layer and second data is assigned to a second modulation layer. In one embodiment of the present invention, the first and second data are assigned based on reliability criteria. The first and second modulation layers are hierarchical modulation layers of the carrier RF signal. Once assigned, the first data is transmitted using the first modulation layer of the carrier RF signal and the second data is transmitted using the second modulation layer of the carrier RF signal. In one embodiment of the present invention, information may be transmitted to one end user using one modulation layer, and information may be transmitted to a different end user using a different modulation layer.

Abstract: A wireless device (200, 310-1) executes a method (400) of reserving a time slot for communication with a second wireless device (200, 310-4) in a communication network 5 (300). The wireless device (200, 310-1) determines whether any antenna beam to be used in a proposed communication with the second wireless device (200, 310-4) communication within the time slot would interfere with any antenna beam used by any first wireless device (200, 310-i) in any existing reservations for the time slot. When any antenna beam to be used in the proposed communication would not interfere with any antenna beam used 10 by any first wireless device (200, 310-i) in any existing reservations for the time slot, the wireless device (200, 310-1) transmits an information element (500) or reserving the time slot for communication with the second wireless device (200, 310-4).

Abstract: Ad-hoc wireless network which operates in accordance with a time division multiple access (TDMA) channel scheme. The network includes a plurality of nodes configured for wireless ad-hoc network communications using at least a first tier waveform and a second tier waveform.

Abstract: The present invention is directed to a digital broadcast system and a data processing method. A broadcast signal in which mobile service data and main service data are multiplexed is transmitted and received. Then, in a broadcasting receiver, mobile service data identification information indicating whether the mobile service data of the broadcast signal provides an internet protocol (IP)-based service is parse from the broadcast signal. And the mobile service data is outputted by using the parsed mobile service data identification information.

Abstract: A CS searches in advance for information about unique words used by neighboring CSs to hold the information in a storage unit. When an LCH establishment request is made by a PS in the cell of the CS, it is confirmed whether or not there is an empty traffic slot. Further, with reference to the unique word information of the neighboring CSs of the same frequency and the same slot as the empty slot to be allocated, an unused unique word pattern is allocated.

Abstract: Techniques for transmitting data in a communication system are described. A packet may be partitioned into multiple subpackets, and each subpacket may be encoded separately. The subpackets may be mapped to resources assigned for transmission of the packet, with at least one subpacket being mapped to a subset of the assigned resources. The assigned resources may include multiple tiles, with each tile corresponding to a block of time frequency resources. The subpackets may be mapped to the tiles such that (i) the subpackets are mapped to equal number of tiles to achieve similar decoding performance, (ii) each subpacket is mapped to at least NMIN tiles, if available, to achieve a certain minimum diversity order for the subpacket, and/or (iii) each subpacket is mapped to a subset of the multiple tiles, if possible, so that the subpacket can be decoded without having to demodulate all of the tiles.

Abstract: A transmitting/receiving system includes a control field controlling a transmitting priority of a dynamic slot is included in each communication cycle, and a node of the transmitting/receiving system sets control information including a preferential usage request for a dynamic slot that the node transmits in the control field and notifies all nodes in the transmitting/receiving system of the preferential usage request for the dynamic slot.

Abstract: In an embodiment, a method for controlling an uplink signal transmission power in a communication device is provided. The method may include receiving a first message in a control channel modification time period, the first message including scheduling information about the timing of the transmission of a second message, the second message including an uplink signal transmission power related information, which will be transmitted by another communication device in the same control channel modification time period, controlling the communication device to receive the second message in accordance with the scheduling information, and controlling the uplink signal transmission power, which is used by the communication device for transmitting signals, depending on the uplink signal transmission power related information.

Abstract: A method and matrixes for transmitting an transport format combination indicator is disclosed. The matrixes according to the invention comprising five column vectors of 32 elements of binary code derived from OVSF codes which are to be multiplied to the lower bits of a TFCI and one column vector of 32 elements of 1 when (32,6) codes are used.

Abstract: An arbitration mechanism provides quality of service guarantees for time-sensitive signals sharing a local area computer network with non-time-sensitive traffic. Device adapters are placed at all access points to an Ethernet network. The device adapters limit admission rates and control the timing of all packets entering the network. By doing so, collisions are eliminated for timesensitive traffic, thereby guaranteeing timely delivery. A common time reference is established for the device adapters. The time reference includes a frame with a plurality of phases. Each of the phases is assigned to a device adapter. Each device adapter is allowed to transmit packets of data onto the network only during the phase assigned thereto. The length of the phases may be modified in accordance with the number of packets to be transmitted by a particular device adapter. A master device adapter may be appointed to synchronize each of the device adapters.

Abstract: Applications executed out of router memory may acquire additional bandwidth that is not being used by other applications, in order to speed up network traffic. Scavenging may occur up to a point where current congestion is detected, at which point any scavenged bandwidth is relinquished and the application returns to its prescribed limit. After current congestion is mitigated, scavenging may occur up to a limit below the point where congestion was detected. After a predetermined interval, additional scavenging may occur beyond this limit until a preset bandwidth limit is reached.

Abstract: A transmission device (ET) is intended to be a component of a time multiplexing (RC) transmission infrastructure with at least one channel and in different transmission time slots, of multimedia contents, such multimedia contents being arranged in at least two complementary data layers. Said device (D) is responsible, in the presence of an association of a time slot to each complementary layer constituting a channel multimedia content, i) for separating the complementary layers of each multimedia content to be transmitted, ii) for chopping up the separated complementary layers into portions of selected sizes, and iii) for incorporating each portion of a layer into a burst so as to transmit each burst during a time slot associated to the layer comprising the portion it integrates.

Abstract: The TDMA receiver comprises a control unit for allocating to each of a plurality of transmitters time intervals during which the transmitter is allowed to transmit signals towards the TDMA receiver, a receiving unit for receiving an incoming signal resulting from the multiplexing of different signals which are output by the plurality of transmitters during the allocated time intervals and in the predetermined frequency band, the incoming signal thus consisting, in the predetermined frequency band, of a TDM signal, a processing unit for extracting and processing the TDM signal, and a spectrum determination unit for determining the spectrum of the incoming signal. The control unit is designed to synchronize the operation of the spectrum determination unit as a function of the time intervals allocated to the transmitters for the determination of the spectrum of the incoming signal in the predetermined frequency band.

Abstract: A method, an apparatus, and a computer program product for wireless communication are provided in which an uplink semi-persistent scheduling release is received an HARQ ACK is determined whether to be transmitted in response to the received uplink semi-persistent scheduling release.

Abstract: The invention relates to a method of communication in a wireless communication system comprising a first station and at least a second station wherein each of the station for at least a part of the time controls the communication within the system. The first station encodes and transmits messages having a first format in a first mode using at least one communication channel or having a second format in a second mode using one communication channel. The first and second formats have a common part. The second station receives and decodes at least the common part of messages transmitted either the first mode or the second mode. The common part comprises information on one or more upcoming transmissions of the first station.

Abstract: A method is described for transmitting information in a communication channel of a wireless communication system in which the communication channel is divided into a plurality of time slots of equal duration and each of the time slots is further sub-divided into multiple sub-slots or resource units. In one illustrative embodiment, the communication channel is divided into time slots according to a time division multiple access scheme. Each time slot is then further code-multiplexed into one or more sub-slots according to a code division multiple access scheme. Each of the sub-slots is therefore capable of carrying a separately coded transmission within the communication channel so that multiple simultaneous transmissions can occur in any given time slot.

Abstract: The invention relates to a device to be used in a wireless communication system with CSMA-based MAC, comprising transmitting circuitry for transmitting at least a first and a second RTS message and at least a first and a second data packet on a transmission medium, and a spatially selective antenna. It is further proposed that the device uses a distributed antenna that combines the antenna elements of several devices and that the device observes the transmissions of other devices, analyzes the observed transmissions for transmission patterns and adapts its own transmissions to the detected transmission patterns. The invention further relates to a system, a method and a computer program to be used in a wireless communication system.

Abstract: A system and method for bandwidth sharing in a distributed wireless client application using inverse multiplexing termination. The system includes: a group of collocated client playback devices having wide area network (WAN) and local area network (LAN) connectivity, and a centralized inverse multiplexing (IMUX) server which optimizes shared bandwidth of both the WAN via inverse multiplexing and the LAN using either broadcast or multicast of all virtual multiplexing paths to all other client playback devices of the group of collocated client playback devices. Other embodiments are disclosed.

Abstract: In operation, a transmitting device selects a synchronization pattern associated with the desired timeslot that is at least mutually exclusive from synchronization patterns associated with other timeslots on the same frequency in the system. Once selected, the transmitting device transmits a burst embedding the synchronization pattern that was selected, where appropriate. If the receiving device detects the synchronization pattern, it immediately synchronizes with the timeslot with confidence that it is synchronizing to the desired timeslot by using sets of synchronization patterns associated with the desired timeslot that are at least mutually exclusive from synchronization patterns associated with the other timeslots on the same frequency.

Abstract: A transmission method in a wireless telecommunication system including at least a base station intended to communicate with terminals over bidirectional communication channels, wherein one or more supplementary symbols that are formed of a set of pilot sequence elements are transmitted between the base station and the terminal during a time delay. The method includes the steps of: obtaining the multiplexing resources of the wireless telecommunication system, assigning to at least one obtained multiplexing resource, pilot sequence elements, and transferring at least one supplementary symbol that includes pilot sequence elements.

Abstract: A method for efficiently scheduling virtual resource blocks to physical resource blocks is disclosed. In a wireless mobile communication system that supports a resource block group (RBG) allocation scheme, for distributed mapping of consecutively allocated virtual resource blocks to physical resource blocks, there is proposed a mapping method capable of increasing the number of distributed virtual resource blocks to a maximum while satisfying gap limitations, when the length of the physical resource blocks is different from the length of the distributed virtual resource blocks. Also, the number of distributed virtual resource blocks and the structure of an interleaver are limited for efficient scheduling.

Abstract: A physical frame is generated and transmitted to a destination terminal. In this physical frame, one of a data frame, an acknowledgement frame, and an acknowledgement request frame, and a transmission permission frame which is used in place of a normal Ack frame associated with a delayed Block Ack, and permits the destination terminal to perform piggyback transmission, are aggregated.

Abstract: A multi-tone modem with components forming a transmit path and a receive path configured to couple to a wired communication medium for at least intermittent communication of frequency division multiplexed multi-tone modulated communication channels thereon. A Fourier transform component transforms received communication channels between a time domain and a frequency domain and vice-versa. Selected components on the receive path determine alignments between the received multiplexed communication channels in the time domain using alignment determinations made in both a time domain and frequency domain portions of the receive path. The Fourier transform component transforms a stream of digitized samples of the received multiplexed communication channels from the time to the frequency domain using the alignment determinations made by the selected components on the receive path.

Abstract: A baseband processing module of a wireless terminal includes a Turbo decoding module. The Turbo decoding module decodes a Turbo code word to produce one or more Media Access Control (MAC) packet(s) carried by the turbo decode word. Each MAC packet includes a MAC packet header and the MAC packet payload, which carries one or more Radio Link Control (RLC) Packet Data Units (PDUs). The Turbo decoding module decodes the MAC packet header to determine boundaries of the PDUs carried in the MAC packet payload. The Turbo decoding module decodes RLC PDU headers and RLC PDU payloads of the RLC PDUs. The Turbo decoding module writes the decoded MAC packet header, the decoded RLC PDU headers, and the decoded RLC PDU payloads to memory in a word-aligned format. The Turbo decoding module may also operate in various other Turbo decoding modes.

Abstract: A beacon scheduling method in multi-hop ad-hoc communications is provided. This method can prevent overhead in a manner that a base station (BS) transmits beacon slot information to a carrier sense multiple access (CSMA)/collision avoidance (CA) node (CN) and a gateway (GW) through contention-free time division multiple access (TDMA) communications at initial clustering, the CN and the GW performs a sequential clustering to forward the beacon slot information to a cluster head (CH), the CH aggregates joining messages from nodes and assigns non-colliding beacon slots to the nodes, and the GW uses a beacon slot frame of a beacon transmission period (BTP) used by its selected CH in a beacon reply period (BRP) as well. Accordingly, the CH does not need to separately perform the initialization to elect the beacon slot, and the GW also does not require a separate initialization to select the beacon relay slot.

Abstract: Disclosed is a device and method for compensating for phase distortions in a base station of an OFDMA-based cellular system. The method comprises receiving OFDM symbols from a plurality of mobile stations, canceling a symbol guard interval using a reference timing signal, and performing an FFT (fast Fourier transform) process on the OFDM symbols; dividing the OFDM symbols that have undergone FFT processing into subchannel groups of the mobile stations; restoring phases of the OFDM symbols divided into subchannel groups; and performing channel estimation and equalization on the restored OFDM symbols for each mobile station to thereby perform a demodulation process.