摘要:
A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel.
摘要:
A method setting a maximum number of determinations for computing power allocation responsive to allocating power among multiple users in one subchannel of an OFDM system; beginning determination of maximum sum-throughput of users in the OFDM system with a randomly generated power profile with an iteration including: i) computing a sum-throughput using a power profile; ii) keeping a previous power profile if the sum-throughput of the current power profile sum-throughput is less than the previous power profile sum-throughput; iii) finding an index of power profile that has maximum sum-throughput; and ascertaining power profiles when the iteration is complete.
摘要:
Disclosed is a coded orthogonal frequency-division multiplexing (OFDM) system and method for reducing a peak-to-average power ratio (PAPR). The system and method include a modulator configured to modulate (e.g., using quadrature amplitude modulation (QAM)) coded bits into symbols. The system and method also include an inverse discrete fourier transform (IDFT) module to perform an IDFT on the symbols to produce an OFDM signal. The system and method measure the PAPR of the OFDM signal and transmit the signal to a receiver if the PAPR of the signal is less than a threshold PAPR.
摘要:
A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel.
摘要:
A cross-layer optimization framework for designing of multi-radio/multi-channel wireless mesh networks with network coding to support multiple unicast applications is used. A column-generation-based primal-dual method is used to solve the optimization problem. For network-layer formation, a code construction scheme based on linear programming is used. Delay constraints are imposed on the network code construction so the possible impact of the extra decoding delay to the upper-layer Transmission Control Protocol/Internet Protocol (TCP/IP) performance may be reduced without changing the upper-layer protocols.
摘要:
A space-time coding arrangement for wireless communications is disclosed where the codes are generated through stochastic approximation. The codes can be optimized over a wide range of performance metrics, receiver structures, and channel characteristics.
摘要:
A method includes the steps of: i) listing out all possibilities for first symbol of a two stream signal; ii) determining a second symbol of the two stream signal for each said first symbol listed out, iii) evaluating a metric for each said first symbol and second symbol pair, iv) determining the exact maximum log likelihood ratio for all bits associated with said first symbol using said metrics, v) decoding a codeword-1 using the maximum log likelihood ratios, vi) re-encoding said codeword-1, vii) modulating said re-encoded codeword-1, viii) subtracting said modulated re-encoded codeword-1 from said two stream signal, ix) determining metrics for all possibilities for second symbol in the signal obtained in viii, x) determining the maximum log likelihood ratios for all bits associated with second symbol, and xi) decoding said codeword-2 using the maximum log likelihood ratios for all bits associated with said second symbol.
摘要:
In accordance with the invention, a method includes determining either the number of tones per chunk required to compute per-chunk order responsive to a sub-band bandwidth, a coherence bandwidth and number of chunks, or the number of chunks responsive to a sub-band bandwidth and a coherence bandwidth; determining an order for each chunk; and determining, for each chunk, QR decompositions for all its tones according to the determined order.
摘要:
A flexible scheduling method with tunable throughput maximization and fairness guarantees in resource allocation is required and suitable for high-rate packet data and other services. Our inventive method, named Alpha-Rule, employs a control variable α, that permits dynamic and/or real-time adjustment/tradeoff between aggregate throughput, per-user throughput, and per-user resource allocation. Our method advantageously operates in conjunction with Multiple-Input Multiple-Output techniques such as Space-Time Block Coding (STBC), Bell Labs Layered Space-Time (BLAST) and others, while offering greater flexibility than existing scheduling techniques, e.g., max-C/I or Proportionally Fair (PF).
摘要翻译:需要具有可调吞吐量最大化和资源分配中公平性保证的灵活调度方法,适用于高速率分组数据和其他业务。 我们的创造性方法,称为Alpha规则,采用控制变量α,允许在聚合吞吐量,每用户吞吐量和每用户资源分配之间进行动态和/或实时调整/权衡。 我们的方法有利地与诸如空时块编码(STBC),贝尔实验室分层时空(BLAST)等的多输入多输出技术相结合,同时提供比现有调度技术更大的灵活性,例如max- C / I或比例公平(PF)。
摘要:
A training-based transmission technique for multiple-antenna communication systems is disclosed herein where the transmitted symbols are a superposition of the training symbols and the data symbols.