Abstract: Allocation of multiple training sequences transmitted in a MIMO timeslot from multiple transmit antenna elements is provided. For example, a method of generating signals in a MIMO timeslot, the method comprising: selecting a first training sequence; preparing a first data payload; generating a first signal including the prepared first data payload and the first training sequence; transmitting the first signal in a MIMO timeslot from a first antenna of a network element; selecting a second training sequence, wherein the second training sequence is different from first training sequence; preparing a second data payload; generating a second signal including the prepared second data payload and the second training sequence; and transmitting the second signal in the MIMO timeslot from a second antenna of the network element.

Abstract: Precoding information prior to MIMO transmission is described, comprising determining a suitable preceding perturbation. The perturbation is determined by assembling a list of candidate perturbations in reduced lattice space, transforming these back into information lattice space and determining which candidate precoder perturbation is most suitable given a performance criterion.

Abstract: A cellular communication system Multiple-In Multiple-Out, MIMO, transmitter includes a plurality of antennas, a selector that selects training sequences for messages, a generator that generates messages including selected training sequences, and a transmitter that transmits the messages on the plurality of antennas. The selector selects a training sequence for a message from a set of training sequences in response to an associated antenna on which the message is to be transmitted. The set of training sequences is associated with a cell of the MIMO transmitter and includes disjoint subsets of training sequences for each of the plurality of antennas.

Abstract: Allocation of multiple training sequences transmitted in a MIMO timeslot from multiple transmit antenna elements is provided. For example, a method of generating signals in a MIMO timeslot, the method comprising: selecting a first training sequence; preparing a first data payload; generating a first signal including the prepared first data payload and the first training sequence; transmitting the first signal in a MIMO timeslot from a first antenna of a network element; selecting a second training sequence, wherein the second training sequence is different from first training sequence; preparing a second data payload; generating a second signal including the prepared second data payload and the second training sequence; and transmitting the second signal in the MIMO timeslot from a second antenna of the network element.

Abstract: A cellular communication system comprises a Multiple-In Multiple-Out (MIMO) transmitter and receiver. The MIMO transmitter comprises a message generator for generating MIMO messages comprising selected training sequences and transceivers transmitting the messages on a plurality of antennas. The training sequences are selected by a midamble selector from a set of training sequences in response to an associated antenna on which the message is to be transmitted. The set of training sequences is associated with the cell of the MIMO transmitter and comprises disjoint subsets of training sequences for each of the plurality of antennas. The receiver comprises a transmit antenna detector which determines which antenna of the MIMO transmitter the message is transmitted from in response to the training sequence of the received message.

Abstract: A cellular communication system comprises a Multiple-In Multiple-Out (MIMO) transmitter and receiver. The MIMO transmitter comprises a message generator for generating MIMO messages comprising selected training sequences and transceivers transmitting the messages on a plurality of antennas. The training sequences are selected by a midamble selector from a set of training sequences in response to an associated antenna on which the message is to be transmitted. The set of training sequences is associated with the cell of the MIMO transmitter and comprises disjoint subsets of training sequences for each of the plurality of antennas. The receiver comprises a transmit antenna detector which determines which antenna of the MIMO transmitter the message is transmitted from in response to the training sequence of the received message.

Abstract: The disclosed invention provides an efficient method for beam training to enable spatial multiplexing MIMO operation and spatial combining in a wireless network. The invention discloses a simple and efficient beam-training algorithm and protocol for MIMO operation that operates in high SNR condition for reliable MIMO operation. In one novel aspect, the best MIMO beam combinations are determined after TX sector sweeping and RX sector sweeping. In addition, the selection criteria includes not only signal quality, but also considers mutual interference and leakage among multiple MIMO spatial streams to improve overall MIMO performance.

Abstract: A coherent or a noncoherent transmission mode is automatically selected for a transmission on the basis of an estimated Doppler frequency shift due to a motion of a mobile terminal. A coherent mode is selected if a pilot signal overhead is not excessive to uniquely characterize a Doppler frequency shift, as at lower carrier frequency times relative velocity products. A noncoherent mode is selected if a pilot signal overhead would be excessive to uniquely characterize a Doppler frequency shift at higher carrier frequency times relative velocity products. Both the coherent and noncoherent modes have respective advantages for their respective carrier frequency time relative velocity regimes.

Abstract: An Orthogonal Frequency Division Multiplex (OFDM) communication system comprises OFDM transmitters and an OFDM receiver. The system comprises a subcarrier status data controller for transmitting subcarrier status data to the OFDM receiver. The subcarrier status data indicates the active subcarriers of the OFDM transmitters. The OFDM receiver comprises a receiver which receives a signal comprising a desired signal component from a first OFDM transmitter and interference from at least one interfering OFDM transmitter. The OFDM receiver further comprises a subcarrier status processor which receives the subcarrier status data and a channel estimator which determines channel estimates for at least an air interface communication channel from the first OFDM transmitter and an air interface communication channel from the interfering OFDM transmitter. An interference mitigation processor performs interference mitigation of the interference in response to the subcarrier status data and the channel estimates.

Abstract: A Wireless Local Area Network (WLAN) device and a method thereof. The Wireless Local Area Network (WLAN) device generates a Physical Layer (PHY) protocol data unit (PPDU) comprising a preamble field, a header field and a payload field for transmission, and comprises a MAC module, a modulator, and an RF module. The MAC module generates a header data sequence comprising bandwidth information of the transmission. The modulator modulates the header data sequence using S-QPSK modulation to generate the header field of the PPDU. The RF module transmits the header field.

Abstract: A cellular communication system comprises a first communication network arranged to use a single cell identifier reuse pattern; a second communication network comprising a cluster of communication cells and arranged to use a common cell identifier reuse pattern for broadcast transmissions. The cellular communication system further comprises management logic (146) having broadcast mode logic (150) operably coupled to at least the second communication network; and a plurality of wireless serving communication units operably coupled to the management logic. The broadcast mode logic (150) applies the same common cell identifier to be used by the plurality of wireless serving communication units in transmitting broadcast communications across the cluster of communication cells in the second network.

Abstract: A cellular communication system (100) comprises management logic (146) having broadcast mode logic (150) arranged to support a common cell identifier reuse pattern for broadcast transmissions amongst a cluster of communication cells. A plurality of wireless serving communication units is operably coupled to the management logic. At least one wireless communication unit comprises a receiver for receiving a broadcast signal from both a first serving wireless communication unit and a second serving wireless communication unit wherein both the first serving wireless communication unit and second serving wireless communication unit use a common cell identifier (215) reuse pattern for broadcast transmissions to be used by the at least one wireless communication unit in receiving broadcast communication across the cluster of communication cells.

Abstract: A cellular communication system (100) is arranged to support a single cell identifier reuse pattern using a first communication. Management logic (146) comprises broadcast mode logic (150) arranged to support a common cell identifier reuse pattern for broadcast transmissions amongst a cluster of communication cells using a second communication. A plurality of wireless serving communication units are operably coupled to the management logic. At least one wireless communication unit comprises logic arranged to support a unicast communication using a first communication cell identifier and logic arranged to support broadcast communication using a common cell identifier (215) to be used by the wireless communication unit in receiving broadcast communication across the cluster of communication cells.

Abstract: A time division duplex (TDD) cellular communication system (100) is arranged to support both uplink and downlink communication allocated for unicast time division duplex (TDD) communication that uses a single cell identifier reuse pattern. The TDD cellular communication system (100) comprises a plurality of wireless serving communication units operably coupled to management logic. The TDD cellular communication system (100) further comprises management logic (146) arranged to partition time domain physical resources such that unicast communication using the single cell identifier reuse pattern is supported in a first portion of the time domain physical resource and a broadcast communication using a common cell identifier (215) reuse pattern for broadcast communications is supported in a second portion of the time domain physical resource.

Abstract: A method of sounding and feedback with channel quality information and reduced overhead is provided. A receiving station receives a sounding signal transmitted from an access point over multiple sub-channels of a wide channel in a wireless network. The receiving station detects channel quality based on the received sounding signal for each sub-channel. The receiving station then performs channel estimation based on the received sounding signal and thereby determining feedback information. Finally, the receiving station transmits a feedback message to the access point, the feedback message contains NULL feedback information, reduced feedback information, or channel integrity/quality indicators based on the channel quality information for each sub-channel. Based on the feedback message, the access point may repeat the sounding process, narrow the transmission bandwidth, or select only stations who have indicated uncorrupted channel sounding for MU-MMO transmission.

Abstract: Channel estimation in a MIMO communications system includes performing a decomposition of an initial channel matrix estimate associated with a first subcarrier of a plurality thereof defined in the channel to identify eigenvectors associated with that subcarrier of the received signal, and defining a first beamforming transformation to be applied to the received signal on the basis of the eigenvectors. For each of the other subcarriers, an additional decomposition is performed in order to determine a further beamforming transformation for each subcarrier. The additional decompositions are carried out incrementally such that information determined in one of said decompositions contributes to a later executed decomposition. Further described is a method of transmitting from a multiple antenna transmitter defining a plurality of subcarriers in space, and time or frequency, comprising the same iterative process.

Abstract: A method of dynamic tone grouping (DTG) used by a transmitter in a wireless OFDM system is proposed. First, a sequence of coded and interleaved bits is de-multiplexed into a number of bit-streams. Each bit-stream is mapped into a sequence of QAM symbols, which are grouped into non-overlapping sets of QAM symbols. Unitary transformation is then applied on the QAM symbols to produce groups of complex signals. Finally, the complex signals are dynamically mapped to subcarrier groups based on tone mapping information to improve link performance. The tone mapping information is derived from information associated with each OFDM subcarrier, such as channel state information (CSI). The OFDM subcarriers are grouped into subcarrier groups according to the tone mapping information such that the channel quality of each subcarrier group is balanced. In addition, the tone mapping information is efficiently encoded and transmitted to/from a corresponding receiver.

Abstract: A method of reporting channel state information (CSI) with reduced feedback overhead in a MIMO-OFDM system is provided. A receiver first estimates CSI of a multiple-input multiple-output (MIMO) channel based on a sounding signal transmitted from a transmitter. The CSI comprises L channel response matrices, and each matrix corresponds to an OFDM tone in the MIMO channel. Each channel response matrix is then decomposed into a first CSI component and a second CSI component. The receiver selects a first subset of the first CSI component based on a first tone group size and a second subset of the second CSI component based on a second tone group size. Finally, the receiver transmits the selected subsets of the first and the second CSI components to the transmitter. The reduced feedback does not have significant loss in the information content of CSI because of the coherent bandwidth in typical OFDM systems.

Abstract: A method of simultaneously providing channel quality feedback information in all valid sub-channels is provided to facilitate and improve the performance of dynamic transmission bandwidth adjustment and fast link adaptation. A receiving device receives a sounding signal over a wide channel in a wireless system. The sounding signal is transmitted from a transmitting device over multiple sub-channels of the wide channel. The receiving device estimates channel quality information based on the sounding signal for each sub-channel. The channel quality information includes estimated average SNR and recommended MCS and other channel quality metrics. The receiving device transmits a feedback message to the transmitting device. The feedback message contains the estimated channel quality information for all valid sub-channels within the transmission bandwidth.

Abstract: An Orthogonal Frequency Division Multiplex (OFDM) communication system comprises OFDM transmitters and an OFDM receiver. The system comprises a subcarrier status data controller for transmitting subcarrier status data to the OFDM receiver. The subcarrier status data indicates the active subcarriers of the OFDM transmitters. The OFDM receiver comprises a receiver which receives a signal comprising a desired signal component from a first OFDM transmitter and interference from at least one interfering OFDM transmitter. The OFDM receiver further comprises a subcarrier status processor which receives the subcarrier status data and a channel estimator which determines channel estimates for at least an air interface communication channel from the first OFDM transmitter and an air interface communication channel from the interfering OFDM transmitter. An interference mitigation processor performs interference mitigation of the interference in response to the subcarrier status data and the channel estimates.