1207 results about "Preamble" patented technology

A system, method and program are disclosed for achieving rapid bit synchronization in low power medical device systems. Messages are transmitted via telemetry between a medical device and a communication device. The synchronization scheme uses a portion of a unique preamble bit pattern to identify the communication device allowing for economical communications with a minimum expenditure of energy. A special set of preamble bit patterns are utilized for their unique synchronization properties making them particularly suited for rapid bit synchronization. These unique preamble bit patterns further provide simplification to the preamble error detection logic.

Methods and apparatus are provided for communicating data in a multiple antenna communication system having N transmit antennas. According to one aspect of the invention, a header format includes a legacy preamble having at least one legacy long training field and an extended portion having at least N additional long training fields on each of the N transmit antennas. The N additional long training fields may be tone interleaved across the N transmit antennas and are used for MIMO channel estimation. The extended portion may include a short training field for power estimation. The short training field may be tone interleaved across the N transmit antennas and have an extended duration to support beam steering.

A system and method for initializing a system communication without previous reservations for random access channel (RACH) access includes a first step of defining at least one spread sequence derived from at least one constant amplitude zero autocorrelation sequence. A next step includes combining the spread sequence with a Walsh code to form an extended spread sequence. A next step includes using the extended spread sequence in a preamble for a RACH. A next step includes sending the preamble to a BTS for acquisition. A next step includes monitoring for a positive acquisition indicator from the BTS. A next step includes scheduling the sending of a RACH message. A next step includes sending the RACH message.

An improved power control method and apparatus of a mobile terminal is provided for facilitating random access procedure in a mobile communication system based on a distributed antenna system. A method includes receiving, by the terminal, system information from a base station, the system information including transmit power information for transmitting a random access preamble; calculating a transmit power using the transmit power information; and transmitting the random access preamble using with the calculated transmit power.

A common packet channel assignment method and device in a CDMA (Code Division Multiple Access) communication system is disclosed. The method comprises transmitting an access preamble signal having channel information which is used to access a base station, and then receiving an; access preamble acquisition indicator signal from the base station in response to the access preamble signal. A collision detection preamble for detecting a collision is transmitted in response to the received access preamble acquisition indicator signal. A first signal indicating acquisition of the collision detection preamble and a second signal indicating channel assignment are received, both of which the base station has transmitted in response to the collision acquisition signal. Upon receipt of the first signal, a common packet channel is assigned according to information designated by the second signal.

An uplink signal transmitted by a terminal is received by a satellite wireless communications system. The uplink signal includes a known information element, e.g., a reverse access channel (R-ACH) preamble, spread according to a spreading code specific to a component of a satellite wireless communications system, e.g., a pseudonoise (PN) sequence associated with a satellite beam. A correlation of the received uplink signal with the spreading code over a range of time shifts is determined. The known information element is detected from the determined correlation. The satellite wireless communications system is synchronized with the terminal responsive to detection of the known information element. For example, a delay may be assigned to a receiver of the satellite wireless communications system responsive to detection of the known information element.

In a method of avoiding multiple detection of the same random access channel (RACH) preamble in a wireless communication system, and within a given set of access slots, a given sub-set of available preamble signatures corresponding to a RACH preamble of a user may be detected, so as to avoid multiple RACH preamble detection in a given access slot. Another method may be directed to switching operations of a base station in a communication network. Base station operations may be switched back and forth between multi-sector/single cell operations and single sector/multi-cell operations without changing an existing antenna configuration.

One or more preambles are inserted into frames of Orthogonal Frequency Multiplexing (OFDM)-Multiple Input, Multiple Output (MIMO) signals. The preamble is received by the antennas of a receiver, decoded and compared to known values to provide synchronization, framing, channels estimation, offsets and other corrections to the transmitted signal.

In an OFDMA-based cellular system, a frame of a downlink signal includes a common slot and traffic slots. The common slot includes a synchronization preamble and a cell search preamble. The synchronization preamble has a structure for synchronizing time and frequency, and the cell search preamble has a cell search structure. The traffic slot includes pilot symbols provided on the time and frequency axes. A cyclic prefix is used to estimate initial symbol synchronization, and the initial symbol synchronization and the synchronization preamble are used to synchronize the frame. The synchronization frame and the cell search preamble are used to estimate time and frequency synchronization. The cell search preamble is used to search cells. When the initial synchronization is performed, the cyclic prefix is used to track the frequency, the synchronization preamble is used to track symbol synchronization, and the cell search preamble is used to track fine frequency synchronization.

The invention relates to a random access procedure for use in a mobile communication system. Furthermore, the invention also provides a mobile terminal and a base station that as suitably adapted to perform the random access procedure as well as the definition of a special format of a random access response message signalled during the random access procedure. To suggest a random access procedure that allows more information to be conveyed in the first scheduled transmission of the random access procedure, the invention proposes a random access procedure for use in a mobile communication system, wherein a base station transmits a random access response in response to receiving a random access preamble from a mobile terminal, wherein the random access response message comprises a grant for a scheduled transmission by the mobile terminal and an indication on the uplink transmission mode for the scheduled transmission.

A method for feeding back transmitter beamforming information from a receiving wireless communication device to a transmitting wireless communication device includes a receiving wireless communication device receiving a preamble sequence from the transmitting wireless device. The receiving wireless device estimates a channel response based upon the preamble sequence and then determines an estimated transmitter beamforming unitary matrix based upon the channel response and a receiver beamforming unitary matrix. The receiving wireless device then decomposes the estimated transmitter beamforming unitary matrix to produce the transmitter beamforming information and then wirelessly sends the transmitter beamforming information to the transmitting wireless device.

Systems and/or methods for supporting communications at a reduced bandwidth with a full bandwidth network such as a long-term evolution (LTE) network may be disclosed. For example, inband assignments such as downlink assignments and/or uplink grants may be provided and/or received and transmissions may be monitored and/or decoded based on the inband assignment. Additionally, information (e.g. a definition or configuration) associated with an ePDCCH may be provided and/or received and ePDCCH resources may be monitored and/or decoded based on such information. An indication for support of a reduced bandwidth by the full bandwidth network may also be provided and/or received and control channels in the reduced or narrow bandwidth may be monitored and/or decoded based on the indication. A PRACH preamble and/or a multi-type sub frame definition may also be provided and/or used for support of such a reduced bandwidth.

Systems and methods for receiving an OFDM preamble without knowledge of channel characteristics are provided. An OFDM preamble signal with frequency shifted cyclic extensions is received. Taken together the cyclic extensions form a frequency shifted version of the OFDM preamble signal. Frequency offsets and timing offsets are estimated and corrected in an efficient manner using a simple concatenation approach in the time domain, followed by a summation of the OFDM preamble signal and the concatenation after a transformation of the OFDM preamble and the concatenation into the frequency domain. Phase errors in the frequency domain are estimated and corrected after FFT transformations of the received signals. A valid preamble is detected and additional parameters for receiving subsequently transmitted OFDM symbols in a channel are extracted from the OFDM preamble. The methods are computationally efficient and robust. Receiver implementations for performing the methods in a DVB receiver are disclosed.

The application discloses a paging method and apparatus. In the method, a network device receives a random access preamble from a terminal device, the random access preamble being used for requestinga paging message; the network device acquires a paging identifier associated with the random access preamble; and the network device sends the paging message to the terminal device according to the paging identifier. With this application, the overhead of signaling during paging can be reduced.

A method for broadcasting channel information, available channel and data rate of a base station in a CDMA communication system. The base station receives information indicating that a mobile station has data to transmit, over an access preamble channel. The base station transmits use status information of physical channels and maximum available data rate information on a status indicator channel. The mobile station receives the use status information of physical channels and the maximum available data rate information through the status indicator channel from a base station. The mobile station transmits to the base station an access preamble for requesting allocation of a given physical channel determined depending on the use status information and the maximum available data rate information.

A reply code for a radio frequency identification (RFID) tag, a method of improving a reply code for a radio frequency identification (RFID) tag for interrogation by an interrogator and an RFID tag employing the same. In one embodiment, the reply code includes a preamble having information about a quality of a clock associated with the RFID tag. The reply code also includes a tag identification (ID) code providing a digital signature for the RFID tag. The reply code still further includes an aftamble located aft of the preamble and having information about the quality of the clock. The aftamble cooperates with the preamble to improve a quality of the reply code for interrogation by an interrogator.

An exemplary wireless communication network that includes a base that communicates with remote units located in a cell of the network. A base concatenates information symbols with a preamble corresponding to a destination remote unit. One or more remote units communicating with a base each concatenates information symbols with a preamble corresponding to that remote unit. An adaptive receiver system for a base unit rapidly adapts optimal despreading weights for reproducing information symbols transmitted from multiple remote units. A transmitter system for a base unit concatenates information symbols with a preamble associated with a remote unit in the cell. An adaptive receiver system for a remote unit in a communication network rapidly adapts optimal weights for reproducing a signal transmitted to it by a specific base unit in the network. A transmitter system for a remote unit in a cell of a communication network which concatenates information symbols with preamble associated with the remote unit. A base initiates communication with a desired remote unit by transmitting an initiation codeword in a selected entry slot. One or more remote units each initiates communication with a bse by transmitting an initiation codeword associated with the remote unit in a selected entry slot. A remote unit synchronizes in time and frequency to the base using a sequence of synchronization signals transmitted by the base in a number of entry slots.

An improved method of processing random access procedures, wherein the network receives at least one access burst to allow a network to estimate uplink received timing, the access burst containing at least a preamble, and transmits information for responding to the at least one access burst, while the mobile terminal configures at least one access burst containing at least a preamble and transmits the at least one access burst to allow a network to at least estimate uplink received timing.

The present disclosure relates to a communication method and system for converging a 5^th-generation (5G) communication system for supporting higher data rates beyond a 4^th-generation (4G) system with a technology for internet of things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. A method for receiving system information (SI) by a user equipment (UE) in a wireless communication system is provided. The method includes receiving, from a base station (BS), first type SI associated with SI which is essential for communication with the BS, transmitting, to the BS, a physical random access channel (PRACH) preamble based on the first type SI, receiving, from the BS, a random access response (RAR) message, and receiving, from the BS, second type SI associated with at least one SI which the UE needs.

A communications device includes a demapping and demodulation circuit and processes an OFDM communications signal that includes modulated subcarriers carrying communications data forming a data payload and modulated subcarriers carrying a training sequence forming a preamble. Those OFDM subcarriers carrying the training sequence have a sample for each subcarrier at a frequency bin using evenly spaced, equal amplitude subcarriers that have a set phase of each sinusoid to a specific angle with quadratic phase to form a low peak-to-average power ratio (PAPR) preamble with about a PAPR value of 2.6 decibels (dB). A channel estimate circuit is operative for measuring fluctuations within a flat-top spectrum of the received OFDM communications signal corresponding to the preamble to reflect the frequency response of the communications channel.

Provided are a method for machine type communication (MTC) user equipment (UE) to connect to an evolved Node-B (eNB) in a random access procedure, and an apparatus employing the method. The method for MTC UE to connect to an eNB includes receiving, at the MTC UE, system information or a handover command from the eNB, transmitting, at the MTC UE, a random access preamble to the eNB, receiving, at the MTC UE, a random access response message from the eNB, and transmitting, at the MTC UE, a connection request message or a handover confirm message including information about a dedicated bandwidth of the MTC UE to the eNB such that the MTC UE can be allocated the dedicated bandwidth. Using this method, an eNB is notified of a dedicated bandwidth of MTC UE, and thus can effectively utilize radio resources.

A method for transmitting a preamble over a Random Access CHannel (RACH) in a wireless communication system is provided. The method includes generating a preamble having a length longer than a basic transmission unit, and dividing the preamble into preambles having a length less than the basic transmission unit; and sequentially transmitting the divided preambles over the RACH using different antennas.

A method of generating random access preambles includes receiving information on a source logical index and generating random access preambles in the order of increasing cyclic shift from root ZC sequences with the consecutive logical indexes from the beginning of the source logical index until a predetermined number of the random access preambles are found, wherein the consecutive logical indexes are mapped to root indexes of the root ZC sequences.

A random access channel transmission method in which a user terminal selects a preamble pattern from among a plurality of known preamble patterns and transmits that preamble pattern to a base station, where that transmission method comprises: a step of dividing a cell into a plurality of areas, and setting one or more preamble patterns and the number of repetitions for transmitting the preamble pattern for each area; and a step wherein a user terminal that exists in an are close to the base station transmits a specified preamble pattern one time, and a user terminal that exists in an area far from the base station transmits another specified preamble pattern a plurality of times.

A method of performing random access in a wireless communication system is disclosed. The method of performing random access in a user equipment of a wireless communication system which uses multiple carriers includes transmitting a preamble for random access to a network, receiving a random access response message from the network in response to the preamble, transmitting a connection setup request message to the network, the connection setup request message requesting connection establishment with the network, and receiving a first message from the network, the first message including connection setup information and contention resolution information in a random access procedure. If a user equipment identifier of the user equipment is included in the message, the user equipment determines that it has successfully performed random access and performs a next procedure in accordance with the connection setup information. If the user equipment identifier of the user equipment is not included in the message, the user equipment determines that it has failed in random access and transmits a random access preamble to the network again after the lapse of a predetermined time period.

A method for transmitting a random access preamble using a random access procedure in a mobile communication system. The random access preamble transmission method includes selecting, upon triggering of the random access procedure, one of random access preamble sets predefined between a User Equipment (UE) and an Evolved Node B (ENB) according to whether a radio channel condition is greater than a radio channel condition threshold and a size of a message that the UE will transmit after transmission of the random access preamble is greater than a minimum message size, randomly selecting a random access preamble from the selected random access preamble set, and transmitting the selected random access preamble to the ENB over a random access channel.

A system and method for random access channel (RACH) capture, where user equipment (UE) transmits a series of time-spaced access preambles each having an increasing power level to Node B and terminates access preamble transmission in response to an acquisition indicator (AI) signal returned from Node B and transmits its RACH message part. A collision detection preamble (CDP) is sent immediately after the message or embedded with the message. A collision detection indicator (CDI) signal matching the CDP is transmitted from Node B to the UE identified as having the failed RACH message requesting retransmission of the message. Optionally, the relative retransmission power level is also specified to the UE along with the CDI signal.

A method for generating an orthogonal frequency division multiplexing (OFDM) frame for wireless communications begins by generating a preamble of the OFDM frame, wherein the preamble includes training information and signal information. The method continues by generating a plurality of data fields of the OFDM frame, wherein each of the plurality of data fields includes a plurality of subcarriers, wherein at least some of the plurality of data fields includes, at most, three of the plurality of subcarriers allocated for a pilot signal.

A method of calculating a Head Media Separation (HMS) from a preamble of embedded servo sectors in a disk drive may include steps of reading the preamble, the read preamble being amplified by a variable gain amplifier (VGA) set at a predetermined gain; transforming samples of the read preamble into a first and a second frequency using a discrete time-to-frequency domain transform such as a Discrete Fourier Transform (DFT); calculating the ratio of the magnitude of the discrete time-to-frequency domain transform of the first frequency to the magnitude of the discrete time-to-frequency domain transform of the second frequency; determining the HMS from the calculated ratio, and enabling the predetermined gain to be updated in synchronism with the transforming step.

The present invention addresses a method, apparatus and computer program product for vehicle gateway access in cellular network for vehicle communications. A dedicated Vehicle gateway random preamble is defined to serve the vehicle gateway access to the network in order to resolve the contention during the initial access and thus decrease access latency. In addition to that, a new cause value Vehicle gateway originated data/signaling for the RRC connection establishment request is defined to inform the network that the coming data traffic is from the vehicle communication.