Abstract: Aspects of the present invention provide additional MAC functionality to support the PHY features of a wireless communication system framework. The additional MAC functionality aids in enabling feedback from wireless terminals to base stations. In some aspects of the invention the feedback is provided on an allocated feedback channel. In other aspects of the invention the feedback is provided by MAC protocol data units (PDU) in a header, mini-header, or subheader. The feedback may be transmitted from the wireless terminal to the base station autonomously by the wireless terminal or in response to an indication from the base station that feedback is requested. Aspects of the invention also provide for allocating feedback resources to form a dedicated feedback channel. One or more of these enhancements is included in a given implementation. Base stations and wireless terminals are also described upon which methods described herein can be implemented.

Abstract: Soft information for achieving interference cancellation in downlink transmissions can be communicated over device-to-device (D2D) links, thereby allowing paired user equipments (UEs) to receive downlink transmissions over the same radio resources. More specifically, paired UEs that receive transmissions over the same time-frequency resources may exchange soft or hard information over D2D links in order to facilitate interference cancellation. The D2D links may be unidirectional or bidirectional, and may be established over in-band or out-of-band resources. Paired UEs may be in the same or different cells, and may receive their respective transmissions from the same or different transmit point. UEs may be paired with one another based on various criteria, e.g., interference cancellation capabilities, scheduling metrics, etc.

Abstract: A method embodiment includes defining, by a network controller, one or more operation modes for a radio node in a network. The one or more operation modes includes a hyper transceiver mode, where the hyper transceiver mode configures a virtual transmission point to cooperatively communicate with a virtual reception point in accordance with neighborhood relations of a target radio node. The method further includes selecting one of the one or more operation modes for the radio node and signaling a selected operation mode to the radio node.

Abstract: It is possible to reduce the overhead associated with downlink channel estimation in massive Multiple-Input-Multiple-Output (MIMO) networks by processing training sequences according to a transformation matrix. The transformation matrix maps a generic dictionary to a non-generic dictionary associated with an antenna geometry of a MIMO antenna array. The transformation matrix can be computed based on the two dictionaries. In one embodiment, the training reference signal is precoded to obtain a precoded training reference signal, which is then transmitted over a MIMO antenna array. The training precoder used to precode the training reference signal is designed according to the transformation matrix to mitigate a dependence that the training reference signal transmission has on the antenna geometry.

Abstract: The capacity of a cellular wireless system is increased by operation of base stations or base station sectors arranged to re-use radio resource elements that are used by neighboring base stations or base station sectors, in conjunction with operation of relay stations, which are similarly arranged to re-use radio resource elements used by neighboring relay stations, and where the radio resource elements re-used by the relay stations are different to those used by the base stations. The relay stations provide coverage, particularly in the areas at the boundaries between the areas of coverage of base stations that suffer from interference between signals transmitted from the respective base stations. In addition, the relay stations generally increase the average available carrier to interference ratio compared with a system in which base stations alone are deployed.

Abstract: A method and apparatus are provided for performing acquisition, synchronization and cell selection within an MIMO-OFDM communication system. A coarse synchronization is performed to determine a searching window. A fine synchronization is then performed by measuring correlations between subsets of signal samples, whose first signal sample lies within the searching window, and known values. The correlations are performed in the frequency domain of the received signal. In a multiple-output OFDM system, each antenna of the OFDM transmitter has a unique known value. The known value is transmitted as pairs of consecutive pilot symbols, each pair of pilot symbols being transmitted at the same subset of sub-carrier frequencies within the OFDM frame.

Abstract: Methods and systems are provided that enable an OFDM transmitter to be used for transmitting conventional OFDM or a form of transformed OFDM. A technique is provided for transforming a coded and modulated sequence of samples prior to an IFFT that enables the transformed sequence of samples to be transmitted using conventional OFDM or transformed OFDM. The selection of a transform function for transforming the coded and modulated sequence of samples may be based on optimizing the transform function for particular operating conditions between the transmitter and receiver. In some embodiments of the invention OFDM and time transformed OFDM are multiplexed in time and/or frequency in a transmission frame. In some embodiments of the invention a pilot pattern is provided in which the pilot are sent using OFDM and data is sent using OFDM and/or transformed OFDM.

Abstract: System and method embodiments are provided for enabling flexible and reliable UE-to-UE based relay. The embodiments include using fountain codes for combining signals at a suitable network layer higher than a media access control (MAC) sub-layer and using a MAC sub-layer hybrid automatic repeat request (HARQ) transmission scheme. When a relay UE in a UE group for joint reception receives, from a network access point, a data packet intended for a destination UE in the UE group and including fountain code at the higher network layer, the relay UE sends the data packet to the destination UE and returns a HARQ ACK message at the MAC sub-layer to the access point. The destination UE then receives and decodes the data packet. Subsequently, upon receiving the entire data, the destination UE sends an ACK message at the higher network layer to the access point.

Abstract: The present invention provides a preamble that is inserted into an OFDMA frame and has a common sequence for all the base stations participating in a transmission. The subscriber station performs fine synchronization using the common sequence on the common preamble, and the resulting peaks will provide the locations of candidate base stations. The base station specific search is then performed in the vicinities of those peaks by using base station specific pseudo-noise sequences. With this two stage cell search, the searching window is drastically reduced. The preamble is matched to known values by a respective receiver to decode the signals and permit multiple signals to be transferred from the transmitter to the receiver. The preamble may comprise two parts, Preamble-1 and Preamble-2, which may be used in different systems, including multioutput, multi-input (MIMO) systems.

Abstract: A method and apparatus for improving channel estimation within an OFDM communication system. Channel estimation in OFDM is usually performed with the aid of pilot symbols. The pilot symbols are typically spaced in time and frequency. The set of frequencies and times at which pilot symbols are inserted is referred to as a pilot pattern. In some cases, the pilot pattern is a diagonal-shaped lattice, either regular or irregular. The method first interpolates in the direction of larger coherence (time or frequency). Using these measurements, the density of pilot symbols in the direction of faster change will be increased thereby improving channel estimation without increasing overhead. As such, the results of the first interpolating step can then be used to assist the interpolation in the dimension of smaller coherence (time or frequency).

Abstract: The present invention employs a pilot scheme for frequency division multiple access (FDM) communication systems, such as single carrier FDM communication systems. A given transmit time interval will include numerous traffic symbols and two or more short pilot symbols, which are spaced apart from one another by at least one traffic symbol and will have a Fourier transform length that is less than the Fourier transform length of any given traffic symbol. Multiple transmitters will generate pilot information and modulate the pilot information onto sub-carriers of the short pilot symbols in an orthogonal manner. Each transmitter may use different sub-carriers within the time and frequency domain, which is encompassed by the short pilot symbols within the transmit time interval. Alternatively, each transmitter may uniquely encode the pilot information using a unique code division multiplexed code and modulate the encoded pilot information onto common sub-carriers of the short pilot symbols.

Abstract: A codebook C is provided in a MIMO transmitter as well as a MIMO receiver. The codebook C will include M codewords ci, where i is a unique codeword index for each codeword ci. Each codeword defines weighting factors to apply to the MIMO signals, and may correspond to channel matrices or vectors to apply to the MIMO signals prior to transmission from the respective antennas of the MIMO transmitter. The present invention creates codeword subsets Si for each codeword ci of the codebook C. Each codeword subset Si defines L codewords cj, which are selected from all the codewords ci in the codebook C. The codewords cj in a codeword subset Si are the L codewords in the entire codebook that best correlate with the corresponding codeword ci.

Abstract: A method and apparatus for improving channel estimation within an OFDM communication system. Channel estimation in OFDM is usually performed with the aid of pilot symbols. The pilot symbols are typically spaced in time and frequency. The set of frequencies and times at which pilot symbols are inserted is referred to as a pilot pattern. In some cases, the pilot pattern is a diagonal-shaped lattice, either regular or irregular. The method first interpolates in the direction of larger coherence (time or frequency). Using these measurements, the density of pilot symbols in the direction of faster change will be increased thereby improving channel estimation without increasing overhead. As such, the results of the first interpolating step can then be used to assist the interpolation in the dimension of smaller coherence (time or frequency).

Abstract: Soft information for achieving interference cancellation in downlink transmissions can be communicated over device-to-device (D2D) links, thereby allowing paired user equipments (UEs) to receive downlink transmissions over the same radio resources. More specifically, paired UEs that receive transmissions over the same time-frequency resources may exchange soft or hard information over D2D links in order to facilitate interference cancellation. The D2D links may be unidirectional or bidirectional, and may be established over in-band or out-of-band resources. Paired UEs may be in the same or different cells, and may receive their respective transmissions from the same or different transmit point. UEs may be paired with one another based on various criteria, e.g., interference cancellation capabilities, scheduling metrics, etc.

Abstract: A method of transmitting includes categorizing a transmission between the first device and a second device as one of a plurality of transmission types, and selecting an air interface from a plurality of air interface candidates in accordance with the transmission as categorized. The method also includes sending the transmission to the second device using the selected air interface.

Abstract: System and method embodiments are provided for enabling flexible and reliable UE-to-UE based relay. The embodiments include using fountain codes for combining signals at a suitable network layer higher than a media access control (MAC) sub-layer and using a MAC sub-layer hybrid automatic repeat request (HARQ) transmission scheme. When a relay UE in a UE group for joint reception receives, from a network access point, a data packet intended for a destination UE in the UE group and including fountain code at the higher network layer, the relay UE sends the data packet to the destination UE and returns a HARQ ACK message at the MAC sub-layer to the access point. The destination UE then receives and decodes the data packet. Subsequently, upon receiving the entire data, the destination UE sends an ACK message at the higher network layer to the access point.

Abstract: In some embodiments of the invention, OFDM symbols are transmitted as a plurality of clusters. A cluster includes a plurality of OFDM sub-carriers in frequency, over a plurality of OFDM symbol durations in time. Each cluster includes data as well as pilot information as a reference signal for channel estimation. In some embodiments, a plurality of clusters collectively occupy the available sub-carrier set in the frequency domain that is used for transmission. In some embodiments of the invention data and/or pilots are spread within each cluster using code division multiplexing (CDM). In some embodiments pilots and data are separated by distributing data on a particular number of the plurality of OFDM symbol durations and pilots on a remainder of the OFDM symbol durations. CDM spreading can be performed in time and/or frequency directions.

Abstract: A method and apparatus are provided for reducing the number of pilot symbols within a MIMO-OFDM communication system, and for improving channel estimation within such a system. For each transmitting antenna in an OFDM transmitter, pilot symbols are encoded so as to be unique to the transmitting antenna. The encoded pilot symbols are then inserted into an OFDM frame to form a diamond lattice, the diamond lattices for the different transmitting antennae using the same frequencies but being offset from each other by a single symbol in the time domain. At the OFDM receiver, a channel response is estimated for a symbol central to each diamond of the diamond lattice using a two-dimensional interpolation. The estimated channel responses are smoothed in the frequency domain. The channel responses of remaining symbols are then estimated by interpolation in the frequency domain.

Abstract: A method for operating a device includes determining adaptation criteria for a waveform to be transmitted by a transmitting device over a communications channel towards a receiving device, and adjusting a generalized multi-carrier multiplexing parameter (GMMP) of the waveform in accordance with the adaptation criteria. The method also includes transmitting an indicator of the adjusted GMMP to at least one of the transmitting device and the receiving device.

Abstract: An apparatus for adapting hyper cells in response to changing conditions of a cellular network is disclosed. During operation, the apparatus collects data regarding network conditions of the cellular network. In accordance with the collected network condition data, the apparatus changes an association of a transmit point from a second cell ID of a second hyper cell to a first cell ID of a first hyper cell. Virtual data channels, broadcast common control channel and virtual dedicated control channel, transmit point optimization, UE-centric channel sounding and measurement, and single frequency network synchronization are also disclosed.