814 results about "Synchronization Channel" patented technology

A system constructed comprises a plurality of devices interconnected to a network. At least two of the devices in the system can access streaming audio information over the network, and are capable of providing audio and rendering timing information to other devices in the system. One device, as the handed-off device, is configured to determine correspondences in connection with two information streams received from two information sources. That device comprises an information receiver module, a position identifier module, and a corresponding position utilization module. The information receiver module configured to receive the two information stream. The position identifier module is configured to identify corresponding positions regarding corresponding sequences in the two information streams. The corresponding position utilization module is configured to utilize the identification of the corresponding positions in the two information streams.

A method for enabling mobile coverage extension and peer-to-peer communications in an ad hoc network is provided. The method includes communicating at least one message among the plurality of nodes, wherein the at least one message comprises: an ad hoc zone, wherein the ad hoc zone comprises at least one channel selected from a group of channels comprising: at least one synchronization channel for synchronizing out of coverage nodes, at least one access channel for peer-to-peer communications, and at least one ad hoc relay data / traffic channel for exchanging data during data sessions between one or more nodes.

In a transmitting method for transmitting a transmit signal sequence by a number of subcarriers, a plurality of subcarriers F1, F2, . . . FNSCH exclusively for a synchronization channel are provided, a signal sequence of synchronization channel SCH is transmitted by the plurality of exclusive subcarriers, and a common pilot CPICH or dedicated signal DPCH is transmitted on the other subcarriers. In this case, the signal sequence of the synchronization channel is subjected to differential encoding processing and the differentially encoded signal sequence is transmitted by the exclusive subcarriers.

A base station communicating with a mobile station in a radio communication system by using OFDM for downlink is disclosed. The base station includes a sequence selecting unit configured to select multiple synchronization signal sequences; a synchronization signal generating unit configured to generate a secondary synchronization channel based on a part of the selected synchronization signal sequences and another part of the selected synchronization signal sequences; and a transmitting unit configured to transmit the secondary synchronization channel. The secondary synchronization channel is used to detect cell-specific information.

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 and terminal use methods of obtaining synchronization and system information in a wireless communication system. An operation of a base station includes generating a synchronization signal to be transmitted through a Synchronization Channel (SCH), generating a broadcast signal to be transmitted through a Broadcast Channel (BCH), and transmitting repetitively the SCH and the BCH by performing beamforming on the channels with different transmission beams.

A method, in a first network element of an inter-chassis redundancy (ICR) system, of cooperating with a second network element of the ICR system to provide ICR. The network elements are coupled by a synchronization channel. IP addresses are announced with a favorable traffic direction attribute. It is determined that the second network element either has announced the IP addresses with an unfavorable traffic direction attribute less favorable than the favorable direction attribute, or has not announced the IP addresses. Sessions that are connected through the IP addresses are handled. Session state synchronization messages that include session state for the handled sessions are transmitted over the synchronization channel to the second network element. It is determined, after an occurrence of a failure event that inhibits the first element from handling the sessions, that the IP addresses have been announced by the second network element with a favorable traffic direction attribute.

A wireless communication method and system are provided. A first wireless communication numerology, e.g., OFDM operating parameters, corresponding to a first operational mode is established. A second wireless communication numerology corresponding to a second operational mode is also established. The first wireless communication numerology is different than the second wireless communication numerology. One of the first operational mode and the second operational mode is selected. One of the first wireless communication numerology and the second wireless communication numerology corresponding the selected operational mode is used in which communication in the first operational mode and the second operational mode use substantially similar synchronization channels. The present invention also uses the same superframe structure for the first and second operational modes for Ultra-Mobile Broadband (“UMB”) networks and the same frame structure for the first and second operational modes for Long Term Evolution (“LTE”) networks.

A system, method, and computer readable medium for handoff of a user equipment from a macrocellular system to a femtocell system is provided. A micro-pilot assisted handoff routine may be implemented to facilitate handoff of a user equipment from a macrocellular system to a femtocell system. The femtocell system may transmit very low power pilot, paging, and synch channels on a common frequency used by the macrocellular system. In another embodiment, a mobile assisted handoff routine facilitates handoff of a user equipment from a macrocellular system to a femtocell system. The user equipment's preferred roaming list includes an entry for the femtocell system and specifies a SID / NID and pseudo-noise offset for the femtocell system. The user equipment is configured to periodically enter a search mode to attempt to locate the femtocell system by switching to a femto carrier that is specified in the preferred roaming list.

The present invention relates to an method and an apparatus for upward access, and the method for upward access according to one embodiment of the present invention can comprise the steps of: receiving, from a base station, a synchronization QO channel, a broadcasting control channel and a secondary reference signal; selecting a transmission beam which transmits an upward access signal by using received results from at least one of the synchronization channel, the broadcasting control channel and the QO secondary reference signal; transmitting the upward access signal by using the selected transmission beam; and receiving, from the base station, an access response and initial set-up information of the control channel as a response for the upward access signal. According to the one embodiment of the present invention, the upward access steps can efficiently perform a beam selection.

A unified frame structure for filter bank multi-carrier (FBMC) and orthogonal frequency division multiplexed (OFDM) waveforms may allow FBMC and OFDM frames to be communicated over a common channel without significant inter-frame gaps. The unified frame structure may set an FBMC frame duration to an integer multiple of an OFDM frame element duration to enable alignment of FBMC frames and OFDM frames in the time domain. The unified frame structure may also map control channels in the FBMC and OFDM frames to common resource locations so that the respective control channels are aligned in the time and / or frequency domains. The unified frame structure may also share synchronization channels between FBMC and OFDM frames. Additionally, overhead in an FBMC time division duplexed (TDD) communications channel can be reduced by overlapping time windows appended to FBMC blocks.

A wireless communication method and system are provided. A first wireless communication numerology, e.g., OFDM operating parameters, corresponding to a first operational mode is established. A second wireless communication numerology corresponding to a second operational mode is also established. The first wireless communication numerology is different than the second wireless communication numerology. One of the first operational mode and the second operational mode is selected. One of the first wireless communication numerology and the second wireless communication numerology corresponding to the selected operational mode is used in which communication in the first operational mode and the second operational mode use substantially similar synchronization channels. The present invention also uses the same superframe structure for the first and second operational modes for Ultra-Mobile Broadband (“UMB”) networks and the same frame structure for the first and second operational modes for Long Term Evolution (“LTE”) networks.

A cell search using a Primary Synchronization Channel (P-SCH) and an Secondary Synchronization Channel (S-SCH) received from a Base Station (BS) are provided, in which a Mobile Station (MS) receives a P-SCH signal including at least two different P-SCH synchronization codes in different slots of a frame and detects slot timing and frame timing using the P-SCH signal.

The present invention relates to a wireless communication system. More particularly, the present invention relates to a method for transmitting system information in which a base station that supports a legacy system and an improved-functions legacy system having one or more functions added thereto, transmits system information, wherein said system information transmitting method comprises a step of transmitting a broadcast channel, containing system information for supporting user equipment for the legacy system, in a predetermined number of symbols which follow the synchronous channel in a first subframe of a wireless frame containing a plurality of subframes; and a step of transmitting additional system information for supporting user equipment for the improved system in a second subframe, excluding the first subframe, from among the plurality of subframes. The present invention also relates to a base station which implements said method for transmitting system information.

The present invention provides a method of operating a base station transmitter. The method includes providing a cellular downlink synchronization signal having primary and secondary portions, wherein the primary portion employs a corresponding one of a plurality of different primary signals allocated to adjoining transmission cells. The method also includes further providing cell-specific information in the secondary portion and transmitting the cellular downlink synchronization signal. In one embodiment, the primary portion explicitly indicates a partial cell identification information and the remaining cell identification information is carried in the secondary portion. In another embodiment, the plurality of different primary signals are simply used to avoid the channel mismatch effect. The present invention also provides a method of operating user equipment. The method includes receiving a cellular downlink synchronization signal having primary and secondary portions wherein the timing acquisition is performed in conjunction with the primary synchronization sequence index detection via the primary portion. In addition, the secondary portion provides cell-specific parameters and identifying and extracting the secondary portion.

Disclosed is an apparatus and method for transmitting the synchronization signal in an Orthogonal Frequency Division Multiplexing (OFDM) based cellular system. The cell search process widely used in the OFDM based cellular system is divided into two steps for obtaining the frame timing synchronization and obtaining the cell-specific scrambling code. When designing the channel for obtaining the frame timing synchronization and the channel for obtaining the cell-specific scrambling code, different frequency reuse factors are applied to the synchronization channels of different steps according to the characteristics of each synchronization obtainment step in order to improve the performance of each step.

Provided are a cell search method, a frame transmission method thereof, and a forward link frame structure thereof. The cell search method used by a terminal to search a target cell using reception signals received from a plurality of base stations, each base station transmitting a frame of its cell, in an Orthogonal Frequency-Division Multiplexing (OFDM) cellular system comprising a plurality cells to which a cell-specific scrambling code is assigned includes: detecting a hopping pattern of the target cell using reception sync channel symbols, which are signals corresponding to sync channel symbol positions of the reception signals, wherein the frame of each cell comprises M sync channel symbols code-hopped according to a hopping pattern of the cell, where M is a natural number equal to or greater than 2, each hopping pattern containing M sync channel code sequences and respectively corresponding to each code group to which a scrambling code of each cell belongs, and an arbitrary hopping pattern used in the OFDM cellular system differs from a cyclically shifted result of the hopping pattern, other hopping patterns, or cyclically shifted results of the other hopping patterns; and detecting a code group of the target cell based on the detected hopping pattern. Accordingly, a cell search time and the complexity of the cell search can be reduced.

Disclosed is an apparatus and method for searching a base station in a mobile communications system, in which a mobile station acquires slot timing synchronization from a first signal on a primary sync channel (P-SCH) out of the P-SCH and a secondary sync channel (S-SCH) used for base station search, acquires frame timing synchronization (Fsync) from a second signal on the S-SCH, and determines a primary scrambling code group (PSCG) corresponding to the scrambling codes used by the respective base stations. The method comprises calculating and accumulating P-SCH RSSI values from the first signal at every slot and comparing the accumulated P-SCH RSSI values with first and second accumulation thresholds and providing the first and second search commands; and calculating S-SCH channel received signal strength indicator (RSSI) values from the second signal at every slot in one frame, and updating S-SCH RSSI values corresponding to the one frame as energy matrix values; calculating energy hypotheses corresponding to the energy matrix values using the energy matrix values and a predetermined secondary sync code (SSC) table in response to a first search command, and determining energy hypotheses having a value higher than a predetermined threshold as passed hypotheses; and calculating energy values for the passed hypotheses using the determined passed hypotheses and the SSC table in response to a second search command, and determining an energy hypothesis having a maximum energy as the Fsync and the PSCG.

Disclosed is a method and an apparatus for transmitting a downlink Synchronization CHannel (SCH) in an Orthogonal Frequency Division Multiplexing (OFDM)-based cellular wireless communication system supporting a scalable bandwidth. Herein, initial cell search and neighbor cell search are seamlessly performed. The disclosed method and apparatus disclose a synchronization channel structure applicable to both a Frequency Division Duplex (FDD) system and a Time Division Duplex (TDD) system.

An open-loop power controller of a transmission power control apparatus investigates whether a dedicated control channel DCCH and a synchronization channel SCH overlap. If the channels overlap, the open-loop power controller suspends ordinary open-loop power control processing, increases a target SIR by a satisfactory level and indicates this to a closed-loop power controller. The closed-loop power controller maintains the indicated target SIR and executes closed-loop transmission power control processing based upon the target SIR. The open-loop power controller resumes ordinary open-loop transmission power control processing after DCCH reception ends.

A code-division-multiple-access (CDMA) system employing spread-spectrum modulation. The CDMA system has a base station, and a plurality of subscriber units. The signals transmitted between the base station and subscriber unit use spread-spectrum modulation. The system and method transmits from the base station, a synchronization channel having a chip-sequence signal used by the plurality of subscriber units for synchronization. A first subscriber unit receives the synchronization channel, and determines timing from the synchronization channel. In order to initiate communications with the base station, the first subscriber unit transmits an access signal. The access signal has a plurality of power levels, which typically ramp up. The base station receives the access signal at a particular-power level. The base station then transmits to the first subscriber unit an acknowledgment signal. The first subscriber unit receives the acknowledgment signal, and transmits to the base station, a spread-spectrum signal.

A hierarchical downlink (DL) synchronization channel (SCH) is provided for wireless OFDM / OFDMA systems. The SCH includes a Primary SCH (P-SCH) for carrying PA-Preambles used for coarse timing and frequency synchronization, and a Secondary SCH (S-SCH) for carrying SA-Preambles used for cell ID detection. The total time length occupied by P-SCH and S-SCH is equal to one OFDM symbol time length of a data channel, and S-SCH is located in front of P-SCH in each DL frame. A perfect multi-period time-domain structure is created and maintained in P-SCH to increase preciseness of frame boundary estimation. With overlapping deployment of macrocells and femtocells, a predefined SCH configuration scheme is provided to separate frequency subbands used for macrocells and femtocells such that interferences in S-SCH can be mitigated. In addition, a self-organized SCH configuration scheme is provided to allow more flexibility for femtocells to avoid or introduce interference in S-SCH.

Disclosed is a transmission / reception apparatus and method for providing compatibility between Code Division Multiple Access (CDMA) and Orthogonal Frequency Division Multiplexing (OFDM) in a forward link. The proposed transmission / reception apparatus and method uses a traffic channel based on OFDM while using a pilot channel and a sync channel used in the CDMA scheme. Thus, a transmitter adds a pilot channel signal and a sync channel signal to OFDM-modulated symbols before transmission, and a receiver acquires a pilot channel signal and a sync channel signal, and removes them from a received signal, thereby outputting only pure OFDM-modulated symbols.

Techniques are disclosed that efficiently obtain channel crosstalk estimates in DSL systems and other communication systems that may include unsynchronized channels. For example, a method includes obtaining a first set of estimated measures of crosstalk for a first portion of a plurality of communication channels over which data signals are to be transmitted from a transmitter to a plurality of receivers, and interpolating a second set of estimated measures of crosstalk for a second portion of the plurality of communication channels based on the first set of estimated measures of crosstalk. The first portion of the plurality of communication channels may be a subset of the plurality of communication channels and the second portion of the plurality of communication channels is a remainder of the plurality of communication channels. Each estimated measure of crosstalk may relate to at least one tone associated with at least one of the plurality of communication channels.

Certain aspects of a method and system for a fast cell search using a primary synchronization channel (PSYNC) process in a multimode wideband code division multiple access (WCDMA) terminal are provided. A WCDMA frequency search or a global system for mobile communications (GSM) frequency search is performed based on a current radio access technology (RAT), received signal strength indication (RSSI) scan measurements, and PSYNC detection operations. The RSSI scan measurements may be averaged by making multiple measurements during a measurement period. At least part of the PSYNC detection operations may be performed during a remaining portion of the measurement period. WCDMA carrier frequencies may be marked in accordance with the results of the PSYNC detection operations. For GSM, some of the frequencies may be removed from the search based on the PSYNC marking while the remaining search frequencies may be ranked based on results from the RSSI scan measurements.

A code-division-multiple-access (CDMA) system employing spread-spectrum modulation. The CDMA system has a base station, and a plurality of subscriber units. The signals transmitted between the base station and subscriber unit use spread-spectrum modulation. The system and method transmits from the base station, a synchronization channel having a chip-sequence signal used by the plurality of subscriber units for synchronization. A first subscriber unit receives the synchronization channel, and determines timing from the synchronization channel. In order to initiate communications with the base station, the first subscriber unit transmits an access signal. The access signal has a plurality of power levels, which typically ramp up. The base station receives the access signal at a particular-power level. The base station then transmits to the first subscriber unit an acknowledgment signal. The first subscriber unit receives the acknowledgment signal, and transmits to the base station, a spread-spectrum signal.

A wireless light communication system and method using a plurality of light transmitting units driven by a same alternating current (AC) power, and a light receiving unit for receiving optical signals transmitted by the plurality of light transmitting units are provided. The wireless light communication method includes setting a channel for each of the plurality of light transmitting units such that light transmitting units having an overlapping area that is reachable by optical signals use different channels, detecting zero crossing of the AC power, synchronizing channels by using the detected zero crossing, and transmitting an optical signal through the set channel by using the plurality of light transmitting units, and receiving the optical signal transmitted by each of the plurality of light transmitting units by using the light receiving unit, and analyzing information included in the received optical signal.

The system comprises: a baseband signal sequence generator for generating baseband signal sequence; a power control unit for respectively multiplying the baseband signal sequences by different coefficients in order to make the power of discrete spectrum line corresponding to one part of the baseband signal sequence to be as zero, and make the discrete spectrum line corresponding to another part of the discrete spectrum to be as single-frequency pilot frequency; a multiplexing unit for multiplexing the baseband signal sequence outputted from power control unit into one route of data transmitted to the random frequency hopping unit; a random frequency hopping unit for randomly changing the frequency spectrum position of single-frequency pilot frequency in synchronous channel of each frame; and a synchronous pilot frequency generating unit for generating synchronous pilot frequency sequence according to the data after random frequency hopping.

A mobile terminal identifies a cell boundary of a mobile communication network supporting an asynchronous scheme for handover between different communication systems. For this, a boundary indication base station newly defines boundary indication codewords distinguished from existing codewords used for acquisition of frame synchronization, and transmits one of the boundary indication codewords over a secondary synchronization channel every frame. Upon receiving the boundary indication codeword over the secondary synchronization channel, the mobile terminal recognizes that it is located in a boundary of the mobile communication network supporting the asynchronous scheme, and performs handover to a mobile communication network supporting a synchronization scheme.

A method for transmitting and receiving signals using multi-band Radio Frequencies (RFs) is provided. The method transmits an information unit of a specific layer above a physical layer through a plurality of frequency allocation bands managed by the specific layer and transmits control information identifying each of the plurality of frequency allocation bands. The control information identifying each of the plurality of frequency allocation bands includes a second ID into which a first ID has been converted, the first ID identifying each of the plurality of frequency allocation bands in the physical layer, the second ID identifying each of the plurality of frequency allocation bands managed by the specific layer in the specific layer. To accomplish this, a timing offset is applied to the entirety of a frame or to a preamble (synchronous channel) so that the timing offset is used as the ID. Applying a timing offset to the entirety of a frame or to a preamble (synchronous channel) can achieve an advantage of PAPR reduction.