Abstract: A system and method is presented for establishing relayed communications involving (1) sending a request message from a source node to a destination node through a plurality of intermediate nodes, (2) receiving the request message at the destination node, and (3) sending an acceptance message from the destination node to the source node through at least a subset of the intermediate nodes, wherein an intermediate node relays the request or acceptance message by receiving the message and re-transmitting the message, and wherein the intermediate node is capable of receiving the message from more than one other intermediate node.

Abstract: Systems and methods are presented for conducting a relayed communication involving a source node, a plurality of intermediate nodes, and at least one destination node, involving at the source node transmitting a signal associated with the relayed communication on a first medium allocation, at each one of the plurality of intermediate nodes relaying the signal onto a next medium allocation in response to receiving the signal as transmitted on at least one medium allocation up to a current medium allocation, and at the at least one destination node receiving the signal as transmitted on at least one medium allocation up to a last medium allocation, wherein at least one node among the plurality of intermediate nodes and the at least one destination node receives signals associated with the relayed communication from multiple intermediate nodes as transmitted on at least one medium allocation.

Abstract: Methods and systems for on-demand adaptation of packet time-to-live in time-slotted barrage relay networks are disclosed. For example, one disclosed method includes: transmitting a first packet from a first node in a wireless ad hoc network to a second node in the wireless ad hoc network; determining a first path distance, in terms of number of hops, from the first node to the second node, based on the first packet transmission; transmitting a second packet from the second node to the first node, wherein the second packet includes content representing the first path distance; and determining a time-to-live value for subsequent transfers from the first node to the second node, by taking into account the first path distance, wherein the time-to-live value limits the number of hops each packet is allowed to take in subsequent transfers from the first node to the second node.

Abstract: Systems and methods are presented for controlling the peak-to-average-power of a baseband orthogonal-frequency-domain multiplexing (OFDM) signal by designating a subset of the available subcarriers as information-bearing data-subcarriers, and loading remaining subcarriers by symbols that are a function of the symbols loading the data-subcarriers. At the receiver, the data-dependent subcarriers are optionally combined with data-subcarriers to increase error protection.

Abstract: Methods for coordinating access to a barrage relay networks are disclosed. For example, one disclosed method includes: receiving, by a first node, a first message from a second node on a network; suppressing transmission of messages by the first node; receiving, by the first node, a second message corresponding to the first message or waiting a sufficient amount of time without receipt of the second message; reactivating transmission of the messages by the first node.

Abstract: A system and method is presented for establishing relayed communications involving (1) sending a request message from a source node to a destination node through a plurality of intermediate nodes, (2) receiving the request message at the destination node, and (3) sending an acceptance message from the destination node to the source node through at least a subset of the intermediate nodes, wherein an intermediate node relays the request or acceptance message by receiving the message and re-transmitting the message, and wherein the intermediate node is capable of receiving the message from more than one other intermediate node.

Abstract: Methods and systems for on-demand adaptation of packet time-to-live in time-slotted barrage relay networks are disclosed. For example, one disclosed method includes: transmitting a first packet from a first node in a wireless ad hoc network to a second node in the wireless ad hoc network; determining a first path distance, in terms of number of hops, from the first node to the second node, based on the first packet transmission; transmitting a second packet from the second node to the first node, wherein the second packet includes content representing the first path distance; and determining a time-to-live value for subsequent transfers from the first node to the second node, by taking into account the first path distance, wherein the time-to-live value limits the number of hops each packet is allowed to take in subsequent transfers from the first node to the second node.

Abstract: Methods for coordinating access to a barrage relay networks are disclosed. For example, one disclosed method includes: receiving, by a first node, a first message from a second node on a network; suppressing transmission of messages by the first node; receiving, by the first node, a second message corresponding to the first message or waiting a sufficient amount of time without receipt of the second message; reactivating transmission of the messages by the first node.

Abstract: Systems and methods are presented for conducting a relayed communication involving a source node, a plurality of intermediate nodes, and at least one destination node, involving at the source node transmitting a signal associated with the relayed communication on a first medium allocation, at each one of the plurality of intermediate nodes relaying the signal onto a next medium allocation in response to receiving the signal as transmitted on at least one medium allocation up to a current medium allocation, and at the at least one destination node receiving the signal as transmitted on at least one medium allocation up to a last medium allocation, wherein at least one node among the plurality of intermediate nodes and the at least one destination node receives signals associated with the relayed communication from multiple intermediate nodes as transmitted on at least one medium allocation.

Abstract: Systems and methods are presented for establishing network-wide time synchronization in a time-slotted barrage relay network. In the first phase, nodes obtain coarse, slot-level time synchronization by estimating the time-of-arrival (TOA) of a message that rapidly floods the network via the barrage relay mechanism. In the second phase, fine time synchronization is achieved via a messaging protocol that exchanges TOA information between neighboring nodes.

Abstract: Systems and methods are presented for topology discovery in a multi-hop ad hoc network. The method operates on two time and distance scales. Nodes periodically transmit messages to their immediate neighbors that enable the discovery of their two-hop network topologies (i.e., within two hops). Less frequently, nodes broadcast messages network-wide that enable the discovery of the global network topology at all nodes. In multi-hop ad hoc network architectures that are characterized by efficient broadcast protocols—e.g., Barrage Relay Networks—the proposed method provides a particularly efficacious means for global topology discovery.

Abstract: A method and system are provided in a wireless communications system comprising a plurality of nodes (users) working cooperatively. The system provides cooperative diversity by allowing nodes to actively share their antennas and other resources to obtain spatial diversity. The nodes receive the same message (information data) from a common source. Each node enhances the reliability of the message with a modern forward error correction (FEC) code, converts the FEC encoded message into an ensemble of symbols, divides the ensemble of symbols into packets, modulates, dithers and transmits the packets to a receiving node. The dithering process is performed by varying the signal amplitude, phase, frequency and/or symbol timing of the modulated packets. A unique dither pattern is assigned to each node. The receiving node captures a composite signal comprising the transmitted packets of all or most of the transmitting nodes in the cooperative communications system.

Abstract: A system and method is presented for establishing relayed communications involving (1) sending a request message from a source node to a destination node through a plurality of intermediate nodes, (2) receiving the request message at the destination node, and (3) sending an acceptance message from the destination node to the source node through at least a subset of the intermediate nodes, wherein an intermediate node relays the request or acceptance message by receiving the message and re-transmitting the message, and wherein the intermediate node is capable of receiving the message from more than one other intermediate node.

Abstract: Systems and methods are presented for controlling the peak-to-average-power of a baseband orthogonal-frequency-domain multiplexing (OFDM) signal by designating a subset of the available subcarriers as information-bearing data-subcarriers, and loading remaining subcarriers by symbols that are a function of the symbols loading the data-subcarriers. At the receiver, the data-dependent subcarriers are optionally combined with data-subcarriers to increase error protection.

Abstract: A method of decoding channel outputs using an iterative decoder to provide hard decisions on information bits includes activating each SISO decoder of the iterative decoder to provide soft-decisions associated with the information bits. The method also includes computing a fidelity estimate and stopping decoding based on the fidelity estimate.

Abstract: A method of decoding channel outputs using an iterative decoder to provide hard decisions on information bits includes activating each SISO decoder of the iterative decoder to provide soft-decisions associated with the information bits. The method also includes computing a fidelity estimate and stopping decoding based on the fidelity estimate.

Abstract: Methods, apparatuses, and systems are presented for performing data encoding involving receiving a sequence of data bits, encoding the sequence of data bit according to a code characterized by a parity check matrix (H matrix) to generate a sequence of encoded bits, wherein the H matrix is capable of being expressed as H=[Hp|Hd]=[S|J*P*T], S being a dual-diagonal matrix, J being a single parity check matrix, P being an interleaver permutation matrix, and T being a repeat block matrix, wherein the H matrix is a column permuted version of an original H matrix, wherein clashes associated with an interleaver corresponding to the P matrix are reduced by adopting the H matrix instead of the original H matrix, and outputting the sequence of encoded bits.

Abstract: Embodiments of the present invention provide Forward Error Correcting Code encoders and decoder structures that use DRAM in their memory designs. DRAM is a very attractive memory options in many electronic systems due to the high memory density provided by DRAM. However, the DRAM is typically not included in ASIC or FPGA implementations of encoders and decoders due to complex refresh requirements of DRAM that are required to maintain data stored in DRAM and may interfere with user access to the memory space during refresh cycles. Embodiments of the present invention provide FECC encoder and decoder structures that are implemented using DRAM that do not require complex refresh operations to be performed on the DRAM to ensure data integrity. Accordingly, embodiments of the present invention maximize memory density without the added complexity of introduced by the refresh requirements of DRAM.

Abstract: SAM is a very attractive memory option for systems due to its higher speed and reduced area when compared to RAM. However it is generally not used in implementations of FECCs due to its limitation to sequential accesses. According to the present invention, Forward Error Correcting Code encoder and decoder structures are shown to allow the use of SAM in their memory designs. Thus SAM is utilized in FECC implementations to achieve better area efficiency for the same amount of memory as well as higher throughput for the hardware implementations.

Abstract: The disclosure proposes bit-error-rate (BER) and symbol-error-rate (SER) estimation techniques and its application to incremental-redundancy and rate-adaptation for modern-coded hybrid-ARQ systems. In particular, BER/SER estimators are proposed based on iterative refinement of mixture-density modeling of the bit/symbol decision metrics. For hybrid-ARQ systems, rate-adaptation functions are proposed based on BER/SER estimators for failed transmissions. Methods are disclosed for code-rate selection based on successfully decoded blocks as well as incremental parity size selection for retransmission of failed blocks Techniques disclosed here apply to forward-error-correction codes employed for digital data communication systems.