Abstract: A method and apparatus for improving the accuracy of a round trip time (RTT) estimate between a first device and a second device are disclosed. The method involves calculating an acknowledgement correction factor and a unicast correction factor. These correction factors are used to compensate for symbol boundary time errors resulting from multipath effects.

Abstract: A method and apparatus for improving the accuracy of a round trip time (RTT) estimate between a first device and a second device are disclosed. The method involves calculating an acknowledgement correction factor and a unicast correction factor. These correction factors are used to compensate for symbol boundary time errors resulting from multipath effects.

Abstract: There is provided a computer-executable method of executing an outer join on a parallel database management system. An exemplary method comprises receiving an outer skewed values list (SVL). The outer SVL may comprise values that are indicated to be skewed. The exemplary method further comprises receiving an inner SVL. The inner SVL may comprise values that are indicated to be skewed. Additionally, the exemplary method comprises partitioning the outer table and the inner table across a plurality of join instances, based on the outer SVL and the inner SVL. A missing skew value is identified. The missing skewed value may be a value of the inner SVL that is not found in the inner table. The outer join is performed using the plurality of join instances, based on the missing skewed value.

Abstract: A method for creating a joined data set from a join input data set is disclosed. The method starts by categorizing the join input data set into a high-skew data set and a low-skew data set. The low-skew data set is distributed to the plurality of CPUs using a first distribution method. The high-skew data set is distributed to the plurality of CPUs using a second distribution method. The plurality of CPUs process the high-skew data set and the low-skew data set to create the joined data set.

Abstract: A method and apparatus for improving the accuracy of a round trip time (RTT) estimate between a first device and a second device are disclosed. The method involves calculating an acknowledgement correction factor and a unicast correction factor. These correction factors are used to compensate for symbol boundary time errors resulting from multipath effects.

Abstract: A method of estimating a number of unique entry counts of an attribute in a database comprises, with a processor: identifying a sample of entries from an attribute database, determining frequencies of a number of input observations of the sample of entries, determining a number of high frequency values of the sample of entries, and estimating a number of unique entry counts of an attribute within the attribute database using a counting Bloom filter and based on the frequencies of the input observations and the high frequency values.

Abstract: A method of providing synchronization-free station locating in a wireless network is provided. In this method, an AP having a known location sends a unicast packet to the station and notes its time of departure TOD(D). The station receives the unicast packet, notes its time of arrival TOA(D), sends an acknowledgement packet to the AP, and notes its time of departure TOD(D_ACK). The AP receives the acknowledgment packet and notes its time of arrival TOA(D_ACK). Notably, a distance between the AP and the station can be accurately determined using a first difference between the TOA(D_ACK) and the TOD(D) and a second difference between the TOD(D_ACK) and the TOA(D). A plurality of such computed distances between a plurality of APs and the station can be used to determine an accurate location of the station.

Abstract: A low-density parity-check (LDPC) codeword is decoded by performing a partial parity check, and based on the partial parity check, determining whether an iteration condition is met. Determining whether the iteration condition is met includes determining whether a time to decode a last codeword is approaching. Determining whether the iteration condition is met can additionally include determining whether a number of partial iterations reaches a maximum number of iterations and/or determining whether hardware resources are becoming limited. If the iteration condition is met, a decoding result is reported. If the iteration condition is not met, then a plurality of check nodes are updated and a parity check is performed.

Abstract: Systems and methods are provided for performing a nested join operation. Partitioning key values are computed for an outer data source using a partitioning key function used to partition an inner table. A join process is established for each of a plurality of partitions of the inner table (at 204), with a given partition of the inner table representing a plurality of partitioning key values. Each row from the outer data source is routed to a join process according to its associated partitioning key value (at 206). The inner table is probed to return a row from the inner table having the partitioning key value associated with the row from the outer data source (at 208). The row from the outer data source and the row returned from the inner table are joined to form a row in a combined table (at 210).

Abstract: A method and apparatus for improving the accuracy of a round trip time (RTT) estimate between a first device and a second device are disclosed. The method involves calculating an acknowledgement correction factor and a unicast correction factor. These correction factors are used to compensate for symbol boundary time errors resulting from multipath effects.

Abstract: The position of a target wireless device in a wireless communication network can be calculated relative to a predetermined number of reference wireless devices in the wireless communication network to preclude the need for fixed/absolute reference points. The reference wireless devices can be selected based, at least in part, on comparing one or more performance measurements associated with each wireless device against one or more corresponding threshold performance measurements. The position of each of the reference wireless network devices relative to each other is determined based, at least in part, on a distance between each pair of the reference wireless network devices. The relative position of the target wireless network device is determined based, at least in part, on the position of each of the reference wireless network devices relative to each other and a distance between the target wireless network device and each of the reference wireless network devices.

Abstract: A method for decoding an LDPC (low-density parity check) code word. The method includes receiving a plurality of LLR (log likelihood ratio) terms from a demodulation unit of a receiver and generating a scaling factor in accordance with at least one parameter descriptive of communication channel conditions for the receiver. The scaling factor is applied to each of the plurality of LLR terms to compute a corresponding plurality of scaled LLR terms. An iterative layered belief propagation algorithm is then executed by using the plurality of scaled LLR terms to generate decoded information.

Abstract: A method of providing synchronization-free station locating in a wireless network is provided. In this method, an AP having a known location sends a unicast packet to the station and notes its time of departure TOD(D). The station receives the unicast packet, notes its time of arrival TOA(D), sends an acknowledgement packet to the AP, and notes its time of departure TOD(D_ACK). The AP receives the acknowledgment packet and notes its time of arrival TOA(D_ACK). Notably, a distance between the AP and the station can be accurately determined using a first difference between the TOA(D_ACK) and the TOD(D) and a second difference between the TOD(D_ACK) and the TOA(D). A plurality of such computed distances between a plurality of APs and the station can be used to determine an accurate location of the station.

Abstract: A method for decoding an LDPC (low-density parity check) code word. The method includes receiving a plurality of LLR (log likelihood ratio) terms from a demodulation unit of a receiver and generating a scaling factor in accordance with at least one parameter descriptive of communication channel conditions for the receiver. The scaling factor is applied to each of the plurality of LLR terms to compute a corresponding plurality of scaled LLR terms. An iterative layered belief propagation algorithm is then executed by using the plurality of scaled LLR terms to generate decoded information.

Abstract: A method of providing synchronization-free station locating in a wireless network is provided. In this method, an AP having a known location sends a unicast packet to the station and notes its time of departure TOD(D). The station receives the unicast packet, notes its time of arrival TOA(D), sends an acknowledgement packet to the AP, and notes its time of departure TOD(D_ACK). The AP receives the acknowledgment packet and notes its time of arrival TOA(D_ACK). Notably, a distance between the AP and the station can be accurately determined using a first difference between the TOA(D_ACK) and the TOD(D) and a second difference between the TOD(D_ACK) and the TOA(D). A plurality of such computed distances between a plurality of APs and the station can be used to determine an accurate location of the station.

Abstract: Optimized query plans are partitioned into equivalence groups that each include equivalence classes. Each equivalence group corresponds to a particular compiled, normalized, and parameterized query plan prior to optimization. Each equivalence class within an equivalence group corresponds to a different query plan corresponding to the particular compiled, normalized, and parameterized query plan represented by the equivalence group that has been optimized with respect to the selectivity of one or more predicate clauses of the query that is compiled to produce the particular compiled, normalized, and parameterized query plan. Optimized query plans are cached according to their respective equivalence groups and equivalence classes.

Abstract: One example discloses a database management system that can comprise a memory for storing computer executable instructions and a processing unit for accessing the memory and executing the computer executable instructions. The computer executable instructions can comprise a compiler to amortize the execution resource cost of searching a search space corresponding to a received query over a plurality of searches.

Abstract: A system and method for decoding a low-density parity-check (LDPC) codeword. The method includes updating a portion of a plurality of variable nodes and performing a partial parity check based on the updated variable nodes. Based on the result of the partial parity check and an iteration condition, a determination is made as to whether to report a decoding result. The method further includes updating a plurality of check nodes and a parity check may be performed. Based on the parity check, a determination as to whether to report a decoding result is made. The iteration number may then be checked for a match with an iteration condition to determine whether to report a decoding result.

Abstract: There is provided a computer-executable method of executing an outer join on a parallel database management system. An exemplary method comprises receiving an outer skewed values list (SVL). The outer SVL may comprise values that are indicated to be skewed. The exemplary method further comprises receiving an inner SVL. The inner SVL may comprise values that are indicated to be skewed. Additionally, the exemplary method comprises partitioning the outer table and the inner table across a plurality of join instances, based on the outer SVL and the inner SVL. A missing skew value is identified. The missing skewed value may be a value of the inner SVL that is not found in the inner table. The outer join is performed using the plurality of join instances, based on the missing skewed value.

Abstract: A method for creating a joined data set from a join input data set is disclosed. The method starts by categorizing the join input data set into a high-skew data set and a low-skew data set. The low-skew data set is distributed to the plurality of CPUs using a first distribution method. The high-skew data set is distributed to the plurality of CPUs using a second distribution method. The plurality of CPUs process the high-skew data set and the low-skew data set to create the joined data set.