Patent application number | Description | Published |
20080304506 | MULTIPLE REQUEST INTERVALS - Methods and apparatuses are presented for communicating using a shared communication medium. A request is sent over the shared communication medium. The shared communication medium is organized to include a request signal space and a scheduled transmission signal space. The request signal space includes a plurality of request segments each having a different location within the request signal space. The scheduled transmission signal space includes a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space. The request occupies more than one request segment. Each of the more than one request segments is randomly selected by the first node. An assignment is received assigning the request to a transmission opportunity in the scheduled transmission signal space. The assignment is made in response to detecting at least one of the more than one request segments. A data transmission is sent using the assigned transmission opportunity. | 12-11-2008 |
20080304507 | QUASISYNCHRONOUS RESERVATION REQUESTS - Methods and apparatuses are presented for communicating using a shared communication medium. A request is sent in a request signal space where the request represents a code sequence that is a member of a set of code sequences. Each member is characterized by an autocorrelation function that has a peak centered at zero time offset. Each member is further characterized by a cross correlation function. The cross correlation function has a low correlation window having a width and surrounding a zero time offset. An assignment is received that assigns the request to a transmission opportunity in a scheduled transmission signal space. The assignment is made in response to detecting the code sequence from receiving multiple requests having relative timing offsets less than the width of the low correlation window. A data transmission is sent using the assigned transmission opportunity in the scheduled transmission signal space. | 12-11-2008 |
20090141680 | FLEXIBLE ASSIGNMENT OF SCHEDULED AND REQUEST TRANSMISSIONS - Methods and apparatus are presented for conducting communications using a shared communication medium. A first request is sent over the shared communication medium. The shared communication medium is organized to include a signal space comprising request signal space and transmission signal space. The request signal space and the transmission signal space have different locations within the signal space. The request signal space includes request segments and the transmission signal space includes scheduled transmission segments. The first request occupies a portion of a transmission segment. An assignment is received associating the first request with a scheduled transmission segment. The assignment takes into account the location of the portion of the transmission segment within the transmission signal space. A data transmission is sent in the scheduled transmission segment associated with the first request. | 06-04-2009 |
20090141736 | CONTENTION-BASED COMMUNICATIONS - Methods and apparatus are presented for conducting communications using a shared communication medium. A message is sent over the shared communication medium. The shared communication medium is organized to include an allocation of node identification signal space and an allocation of data transmission signal space. The allocation of node identification signal space includes a plurality of node identification segments. The allocation of data transmission signal space includes a data transmission segment. The message includes a node identification portion and a data transmission portion. The node identification portion is transmitted in the allocation of node identification signal space and occupies a node identification segment. The data transmission portion is transmitted in the allocation of node identification signal space and occupies the data transmission segment. | 06-04-2009 |
20100150037 | NOVEL PHYSICAL LAYER HEADER STRUCTURE FOR DECODING AND SYNCHRONIZATION - Systems, devices, processors, and methods are described which may be used for the reception of a wireless broadband signal at a user terminal from a gateway via a satellite. A wireless signal may include a series of physical layer frames, each frame including a physical layer header and payload. The received signal is digitized and processed using various novel physical layer headers and related techniques to synchronize the physical layer frames and recover data from physical layer headers for purposes of demodulation and decoding. | 06-17-2010 |
20100150053 | START OF FRAME CORRELATION FOR PHYSICAL LAYER HEADER SYNCHRONIZATION - Systems, devices, processors, and methods are described which may be used for the reception of a wireless broadband signal at a user terminal from a gateway via a satellite. A wireless signal may include a series of physical layer frames, each frame including a physical layer header and payload. The received signal is digitized and processed using various novel physical layer headers and related techniques to synchronize the physical layer frames and recover data from physical layer headers for purposes of demodulation and decoding. | 06-17-2010 |
20100150054 | FALSE LOCK DETECTION FOR PHYSICAL LAYER FRAME SYNCHRONIZATION - Systems, devices, processors, and methods are described which may be used for the reception of a wireless broadband signal at a user terminal from a gateway via a satellite. A wireless signal may include a series of physical layer frames, each frame including a physical layer header and payload. The received signal is digitized and processed using various novel physical layer headers and related techniques to synchronize the physical layer frames and recover data from physical layer headers for purposes of demodulation and decoding. | 06-17-2010 |
20100158179 | SYMBOL TIMING ACQUISITION USING EARLY-LATE INTERPOLATION - Symbol timing acquisition is described for a wireless broadband signal received at a user terminal from a gateway via a satellite. In-phase and quadrature channels of the wireless signal may each be sampled at a rate of one sample per symbol. The samples may be interpolated to generate an early interpolation and a late interpolation for each of the samples. A difference measurement is obtained between the early interpolation and the late interpolation for a set of the samples. A number of the difference measurements may be averaged, and symbol timing may be modified based on the average. This process may be continued on an iterative basis to acquire symbol timing. | 06-24-2010 |
20100159861 | DELTA-THETA FREQUENCY ESTIMATION - Systems, devices, processors, and methods are described which may be used for the reception of a wireless broadband signal at a user terminal from a gateway via satellite. A physical layer header may be identified, the header including a number of subcode blocks. A phase may be estimated for each of the subcode blocks, and intra-header phase differences may be calculated. The intra-header phase differences may be used to calculate a frequency error, which may be corrected. Frequency errors may be monitored and, when such errors fall below a threshold level, an alternative inter-frame frequency error tracking method may be used. | 06-24-2010 |
20110007647 | MF-TDMA SATELLITE LINK POWER CONTROL - A method for determining attenuation settings across carriers in a return link bandwidth of a user terminal comprises determining a first attenuation setting for a user terminal at a first transmission frequency, where the first attenuation setting is based on a first signal quality metric value of a first message sent from the user terminal at the first transmission frequency. The method also comprises determining a second attenuation setting for the user terminal at a second transmission frequency, where the second attenuation setting is based on a second signal quality metric value of a second message sent from the user terminal at the second transmission frequency. The method also comprises determining the attenuation settings across the carriers in the return link bandwidth of the user terminal based on the first attenuation setting and the second attenuation setting. | 01-13-2011 |
20120207198 | SYMBOL TIMING ACQUISITION USING EARLY-LATE INTERPOLATION - Symbol timing acquisition is described for a wireless broadband signal received at a user terminal from a gateway via a satellite. In-phase and quadrature channels of the wireless signal may each be sampled at a rate of one sample per symbol. The samples may be interpolated to generate an early interpolation and a late interpolation for each of the samples. A difference measurement is obtained between the early interpolation and the late interpolation for a set of the samples. A number of the difference measurements may be averaged, and symbol timing may be modified based on the average. This process may be continued on an iterative basis to acquire symbol timing. | 08-16-2012 |
20130155922 | FALSE LOCK DETECTION FOR PHYSICAL LAYER FRAME SYNCHRONIZATION - Systems, devices, processors, and methods are described which may be used for the reception of a wireless broadband signal at a user terminal from a gateway via a satellite. A wireless signal may include a series of physical layer frames, each frame including a physical layer header and payload. The received signal is digitized and processed using various novel physical layer headers and related techniques to synchronize the physical layer frames and recover data from physical layer headers for purposes of demodulation and decoding. | 06-20-2013 |
20130329630 | TANDEM SATELLITE FRAME SYNCHRONIZATION - Systems and methods are described synchronizing communications frames and their respective time slots for satellite communications architectures having multiple satellites in the same orbital slot in such a way that addresses inter-satellite inter-beam interference. In some embodiments, the first and second satellites communicate with a respective number of ground terminals (e.g., gateway and user terminals) according to first and second satellite time slots, respectively. The satellites maintain relative positions in their orbital slot to manifest a maximum path delay difference between first and second path delays, the first path delay being between the first ground terminals and the first satellite, and the second path delay being between the first ground terminals and the second satellite. A synchronization system can offset the first satellite time slots from the second satellite time slots as a function of the maximum path delay difference. | 12-12-2013 |
20130331026 | ROBUST BEAM SWITCH SCHEDULING - Systems and methods are described for robust scheduling of beam switching patterns in satellite communications systems. Embodiments operate in context of a hub-spoke satellite communications architecture having a number of gateway terminals servicing large numbers of user terminals over a number of spot beams. The satellite includes switching subsystems that distribute capacity to the user beams from multiple of the gateway terminals in a shared manner according to a beam group switching pattern. The beam group switching pattern is robustly formulated to continue distributing capacity during gateway outages (e.g., when one or two gateway terminals are temporarily non-operational due to rain fade, equipment failure, etc.). For example, the beam group switching pattern can be formulated to minimize worst-case degradation of capacity across user beams, to prioritize certain beams or beam groups, etc. | 12-12-2013 |