Abstract: Disclosed is a method for wireless typology discovery for train backbone networks.

Abstract: A method and apparatus for hybrid multi-layer transmission includes receiving a multi-layer signal from a source device, wherein the multi-layer signal includes a plurality of sublayers. A quantity of the plurality of sublayers is decoded and partial information relating to the decoded sublayers is transmitted to a destination device.

Abstract: Signals transmitted on the backhaul links of a cloud radio access network may be compressed using joint compression encoding. Joint compression encoding may be performed using a successive estimation-compression architecture. Joint compression encoding may include designing preceding matrices that may be used with signal compression. Joint compression encoding may be applied to signals transmitted on the downlink of the cloud radio access network. One or more baseband signals to be delivered over the backhaul links may be jointly compressed using multivariate compression. Multivariate compression may be implemented using successive compression based on a sequence of minimum mean squared error (MMSE) estimations and per BS compression.

Abstract: Disclosed is a method for wireless typology discovery for train backbone networks.

Abstract: Signals transmitted on the backhaul links of a cloud radio access network may be compressed using joint compression encoding. Joint compression encoding may be performed using a successive estimation-compression architecture. Joint compression encoding may include designing preceding matrices that may be used with signal compression. Joint compression encoding may be applied to signals transmitted on the downlink of the cloud radio access network. One or more baseband signals to be delivered over the backhaul links may be jointly compressed using multivariate compression. Multivariate compression may be implemented using successive compression based on a sequence of minimum mean squared error (MMSE) estimations and per BS compression.

Abstract: A method and apparatus for hybrid multi-layer transmission includes receiving a multi-layer signal from a source device, wherein the multi-layer signal includes a plurality of sublayers. A quantity of the plurality of sublayers is decoded and partial information relating to the decoded sublayers is transmitted to a destination device.

Abstract: A collaborative Hybrid Automatic Repeat reQuest (HARQ) in a broadband wireless communication system using a relay station is provided. A transmitting end includes a distance estimator for estimating a distance to a relay station; a controller for determining whether to execute a collaborative HARQ using the estimated distance to the relay station; and a transmitter for, when the execution of the collaborative HARQ is determined and a retransmission request is received from a receiving end, sending a retransmission packet according to a multiple antenna signal processing scheme by constituting a virtual multiple antenna group with the relay station.

Abstract: An apparatus and method for cooperative transmission in a multi-antenna relay wireless communication system are provided. A receiving end includes an estimator, a reader, a feedback unit and a detector. According to the present invention, the receiving end receives the signal from both the transmitting end and the relay station. Therefore, a reception gain is obtained and a high throughput can be ensured.

Abstract: In one embodiment, a cognitive radio system includes a first transmitter in communication with a first receiver via a wireless channel. The first transmitter receives a plurality of first packets, and transmits the first packets to the first receiver via the channel. A second transmitter in communication with a second receiver and the first receiver via the channel receives a plurality of second packets, receives the plurality of first packets from the first transmitter, and transmits the second packets to the second receiver via the channel. The second transmitter is configured to detect an idle state of the channel. Upon detecting the idle state of the channel, the second transmitter is configured selectively to transmit at least one of the second packets to the second receiver or to relay at least one of the first packets to the first receiver.

Abstract: A single-input single-output (SISO) downlink channel with K users is analyzed in the presence of Rayleigh flat fading. A limited channel state information (CSI) feedback scheme is included, where only an outdated 1-bit feedback per user is available at the base station for each fading block. A closed-form expression for the achievable ergodic sum-rate of the 1-bit feedback scheme is presented for any number of users, as a function of the fading temporal correlation coefficient, the threshold of the 1-bit CSI quantizer and the SNR. The sum-rate scales with increasing number of users as log log K, which is the same scaling law achieved by the optimal non-delayed full CSI feedback scheme.

Abstract: Power control for uplink channels with non-cooperative and rational mobile stations (MS) provided using game theory. As a game leader, a multi-antenna access point (AP) determines the network parameters (bandwidth and the number of receiving antennas) for the power control game played between the mobile stations (MSs) (follower), so as to maximize the network utility per system resource (bandwidth and antennas).

Abstract: A model of a pulse-coupled discrete-time phase locked loops (PLLs) in a wireless network is provided. The PLLs at each node in the network may have an indeterminate order. A method for securing discrete-time distributed phase locked loops (PLLs) in a wireless network by including an outlier detection scheme in the timing update at each node is also provided. The method may include evaluating each collaborating node based on a weighted average of the clock errors and evaluating the dispersion of clock errors.

Abstract: A channel response matrix gathering all unknown elements for all K pilot subcarriers on links between transmitting and receiving antennas, is Least Squares (full-rank) estimated. The interference covariance matrix is estimated from the residual. The correlation of the interference covariance matrix is computed at each new symbol and compared with a threshold. If the interference is significantly changed, the interference covariance matrix is re-initialized, otherwise a running average of the interference covariance matrix is updated with the actual value. Both the updated/re-initialized interference covariance matrix and the autocorrelation matrix of the transmitted pilot sequences (stored in the receiver) are used for whitening the estimated channel matrix before submission to modal filtering for rank reduction. The original spatial and/or temporal correlations are reintroduced in the reduced-rank channel matrix by inverse whitening.

Abstract: A single-input single-output (SISO) downlink channel with K users is analyzed in the presence of Rayleigh flat fading. A limited channel state information (CSI) feedback scheme is included, where only an outdated 1-bit feedback per user is available at the base station for each fading block. A closed-form expression for the achievable ergodic sum-rate of the 1-bit feedback scheme is presented for any number of users, as a function of the fading temporal correlation coefficient, the threshold of the 1-bit CSI quantizer and the SNR. The sum-rate scales with increasing number of users as log logK, which is the same scaling law achieved by the optimal non-delayed full CSI feedback scheme.

Abstract: Power control for uplink channels with non-cooperative and rational mobile stations (MS) provided using game theory. As a game leader, a multi-antenna access point (AP) determines the network parameters (bandwidth and the number of receiving antennas) for the power control game played between the mobile stations (MSs) (follower), so as to maximize the network utility per system resource (bandwidth and antennas).

Abstract: An apparatus and method for cooperative transmission in a multi-antenna relay wireless communication system are provided. A receiving end includes an estimator, a reader, a feedback unit and a detector. According to the present invention, the receiving end receives the signal from both the transmitting end and the relay station. Therefore, a reception gain is obtained and a high throughput can be ensured.

Abstract: In one embodiment, a cognitive radio system includes a first transmitter in communication with a first receiver via a wireless channel. The first transmitter receives a plurality of first packets, and transmits the first packets to the first receiver via the channel. A second transmitter in communication with a second receiver and the first receiver via the channel receives a plurality of second packets, receives the plurality of first packets from the first transmitter, and transmits the second packets to the second receiver via the channel. The second transmitter is configured to detect an idle state of the channel. Upon detecting the idle state of the channel, the second transmitter is configured selectively to transmit at least one of the second packets to the second receiver or to relay at least one of the first packets to the first receiver.

Abstract: A collaborative Hybrid Automatic Repeat reQuest (HARQ) in a broadband wireless communication system using a relay station is provided. A transmitting end includes a distance estimator for estimating a distance to a relay station; a controller for determining whether to execute a collaborative HARQ using the estimated distance to the relay station; and a transmitter for, when the execution of the collaborative HARQ is determined and a retransmission request is received from a receiving end, sending a retransmission packet according to a multiple antenna signal processing scheme by constituting a virtual multiple antenna group with the relay station.

Abstract: The present invention relates to a device and method for channel estimation. The method of channel estimation for slotted radio communication systems, in particular, mobile communication systems determines a least squares estimate of the channel and refines such estimate by a noise reduction through a Reduced-Complexity approach. The refinement includes determination of spatial and temporal subspaces respectively comprising the actual directions of arrival of the signal among all distinguishable directions and the actual times of arrival of the signal among all distinguishable times of arrival, and the projection of the least squares estimate on said subspaces.