Abstract: A Multiple Input Multiple Output (MIMO) single carrier wireless communication system is provided. The system includes a coder for performing block coding on symbols, an extender for collecting the block-coded symbols during one transmit (Tx) signal duration and for performing repetitive extension on the collected symbol vectors by an interval required in a frequency domain, an inserter for inserting ‘0’ to the repetitively extended symbol vectors so that the vectors are mutually orthogonal in a time domain, and a combiner for multiplying the ‘0’-inserted symbol vectors by a phase component so that the vectors are mutually orthogonal in the frequency domain and thereafter for combining the symbol vectors to generate a Tx signal for each antenna.

Abstract: Implementations of improved OSTC decoding are disclosed where received channel output corresponding to a partial OSTC codeword may be used to generate estimated channel output, and where the received channel output and the estimated channel output may be used to reconstruct the OSTC codeword.

Abstract: Examples are disclosed for transmitting and receiving schemes for multiuser single-carrier space time spreading (STS) with frequency domain equalization.

Abstract: Implementations of improved transmission of orthogonal space time codes are disclosed.

Abstract: Examples are disclosed for determining a bit error rate (BER) associated with decoding data transmitted using space-time spreading (STS) in a wireless communication system.

Abstract: Examples are disclosed for transmitting and receiving schemes for multiuser single-carrier space time spreading (STS) with frequency domain equalization.

Abstract: Examples are disclosed for transmitting and receiving schemes for multiuser single-carrier space time spreading (STS) with frequency domain equalization.

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: An apparatus is provided for transmitting a signal in a communication system. Upon receipt of an information vector, the apparatus includes converting the information vector into a plurality of sub-information vectors; performing coding and modulation on each of the sub-information vectors according to a corresponding mode thereby generating a modulation symbol; interleaving the modulation symbol generated for each of the sub-information vectors; allocating power to the interleaved modulation symbol for each individual mode; and beamforming the modulation symbols power-allocated for each individual mode, and transmitting the beamforming symbols.

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 carrier transmission scheme which utilizes space-frequency block coding and frequency domain equalization (SF-SCFDE) is proposed for frequency selective and fast fading channel. It is shown that employing this technique in slow fading environment depicts the same performance as that obtained with space-time coding scheme. However, in the more difficult fast fading channels, the proposed scheme exhibits much better performance.

Abstract: A permuted sequences combination uses a frame structure in which two sync words, each comprising M complex symbols, are appended at the frame start. One benefit is the reduction of the large variance of the timing estimation error in the conventional correlation method. In at least one embodiment, the first sync word, {right arrow over (s)}1, is a predetermined constant amplitude zero autocorrelation (CAZAC) sequence. The second sync word, {right arrow over (s)}2, is a permutation of the first such that the combination of the two received sync signal vectors perform sliding window processing where the peak occurs at the correct frame start. The permuted sequences combination can be used in both AWGN channel and multi-path environments.

Abstract: A method is provided for ordering retransmissions in a Multi-Input Multi-Output (MIMO) system using N×M antennas. A transmitter splits a coded data stream into N sub-packets, and transmits the N sub-packets to a receiver via N transmission antennas. The receiver removes interferences of the N sub-packets received via M reception antennas, and independently decodes the interference-removed sub-packets. The receiver transmits an acknowledgement (ACK) or a negative acknowledgement (NACK) to the transmitter based on errors included in the decoded sub-packets. Upon receipt of the NACK, the transmitter retransmits to the receiver a sub-packet retransmission using ordering based on an Alamouti space-time coding scheme.

Abstract: Methods and/or systems for reducing peak-to-average-power ratio (PAPR) may utilize rotation among transmit channels and/or inversion of polyphase sequences of sub-blocks of an orthogonal frequency-division multiplex (OFDM) sequence in a multi-input multi-output (MIMO) 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: Orthogonal frequency division multiplexing (OFDM) has been specified by IEEE 802.11a standard as the transmission technique for high-rate wireless local area networks (WLANs). Performance of an OFDM system, however, is heavily degraded by random Wiener phase noise, which causes both common phase error (CPE) and inter-carrier interference (ICI). A method and algorithm is disclosed for efficiently eliminating the effect of phase noise in OFDM based WLANs.

Abstract: Practical transmission power adaptation in multicarrier code division multiple access (MC-CDMA) communications is using either a frequency domain technique or a time domain technique or a combined frequency and time domain technique in response to channel variations. With frequency domain power adaptation, the transmission power is allocated over the N? (1?N??N) strongest subcarriers rather than over all possible N subcarriers, where the strongest subcarriers are understood to exhibit the highest channel gains. A substantially optimal N? can be chosen so that the average bit error rate (BER) is minimized. In the time domain power adaptation technique, transmission power is adapted so that the desired signal strength at the receiver output is maintained at a fixed level.

Abstract: Examples are disclosed for transmitting and receiving schemes for multiuser single-carrier space time spreading (STS) with frequency domain equalization.

Abstract: Examples are disclosed for determining a bit error rate (BER) associated with decoding data transmitted using space-time spreading (STS) in a wireless communication system.