Mediatek Corporation

Mediatek Singapore Pte. Ltd.

Hfi Innovation Inc.

Tze-Ping Low

Jangwook Moon

Lung-Sheng Tsai

Chien-Hwa Hwang

William Plumb

Yi-Ju Liao

Yih-Shen Chen

Per Johan Mikael Johansson

Craig Burnet

Pei-Kai Liao

Tsang-Wei Yu

Timothy Perrin Fisher-Jeffes

Zoran Zvonar

Yonggang Hao

Pang-Chang Lan

Yu-Han Yang

A method of modulating and demodulating superposed signals for MUST scheme is proposed. A transmitter takes bit sequences intended for multiple receivers under MUST scheme to go through a 'bit sequence to constellation points' mapper before entering the modulators to satisfy the Gray coding rule and to achieve high demodulation performance for the receivers. In a first method, each bit sequence is assigned for each constellation point on the constellation map to satisfy one or more conditions under different power split factors. In a second method, the constellation map is divided into sub-regions according to the clustering of the constellation points for bit sequence assignment. A near-UE may use an ML receiver for demodulation and decoding the superposed signal. A far-UE may use an ML receiver or an MMSE receiver for demodulation and decoding the superposed signal.

Signal modulation and demodulation for multiuser superposition transmission scheme

A technique, as well as select implementations thereof, pertaining to dual receive processing in wireless communications is described. The technique may involve receiving, by a plurality of receive processing modules, an incoming signal from an antenna to provide a plurality of processing results. The technique may also involve generating, by a determination mechanism, a determination output based on the plurality of processing results. The determination output may include either one or more decoding metrics based on a respective processing result from one of the plurality of receive processing modules or a weighted combination of more than one respective processing result from more than one receive processing module of the plurality of receive processing modules. The technique may further involve decoding, by a decoder, the determination output to provide a decoded signal.

Dual receive processing in wireless communications

A mobile communication device including a wireless transceiver and a controller is provided. The wireless transceiver includes a single interference cancellation or suppression receiver and is configured to perform wireless transmission and reception to and from a cellular station. The controller is configured to receive signaling information of a Multi-User Superposition Transmission (MUST) operation from the cellular station via the wireless transceiver, determine whether to perform a Network-Assisted Interference Cancellation and Suppression (NAICS) operation or the MUST operation according to the signaling information, and not perform both the NAICS operation and the MUST operation simultaneously.

Apparatuses and methods for optimizing usage of a single interference cancellation and suppression receiver

When the codeword level interference cancellation (CW-IC) is used at the receiver in conjunction with the superposition coding scheme at the transmitter, it is helpful if the soft buffer at the receiver is reserved not only for the desired transport blocks (TBs) but also for the interfering TBs handled by the CW-IC. In so doing, the soft channel bits of interfering TBs at multiple (re)transmissions can be combined to enhance the success rate of data decoding. A soft buffer partition method for the soft channel bits of the desired and interfering TBs in the superposition coding scheme is proposed. The proposed method has a full flexibility in adjusting the soft buffer sizes for the desired and interfering TBs.

Soft buffer partition for superposition coding

Methods for rate matching with soft buffer size setting at the transmitter and soft channel bits storage at the receiver for superposition coding are proposed. In the superposition coding scheme, a transport block intended to one UE needs to be decoded by another UE's receiver. However, the soft buffer sizes per code block of the two receivers may not be the same since the size depends on the UE category. The base station can signal the soft buffer size used at the transmitter for rate matching to the UEs for superposition decoding. A UE stores information bits associated with an interfering signal in its soft buffers in accordance with the soft buffer size used at the transmitter for rate matching. As a result, the UE can decode and subtract the interfering signal from the desired signal for superposition coding.

Rate matching and soft channel bits storage for superposition coding

A Precoding-codebook-base Secure Uplink (PSU) scheme is proposed to utilize the channel reciprocity, uniqueness, and randomness in solving the secure initiation problem. A UE receives a first reference signal via first downlink channel in a mobile communication network. The UE performs channel estimation based on the first reference signal and thereby obtaining a first channel response matrix of the first downlink channel. The UE then encodes secrecy information onto a second reference signal. The UE transmits the second reference signal via a second uplink channel. The secrecy information is hidden in the uplink channel through a precoding operation such that the secrecy information can be extracted when the second uplink channel is reciprocal to the first downlink channel.

Precoding-codebook-based secure uplink in LTE

When the codeword level interference cancellation (CW-IC) is used at the receiver in conjunction with the superposition coding scheme at the transmitter, in order to guarantee the success of signal reception, restrictions of scheduling decisions in resource allocation of superposed transport blocks may occur. A method to mitigate the scheduling restrictions is proposed. For a low-geometry UE in NOMA operation, one sub-band is used as the basic scheduling unit. As a result, data in resource blocks scheduled for NOMA operation and data in resource blocks scheduled for other non-NOMA operation correspond to different transport blocks. Therefore, a high-geometric UE only needs to decode the data scheduled for NOMA. The base station does not need to impose additional scheduling restrictions and signaling overhead.

Resource allocation for superposition coding

A method is proposed to enable a UE performing codeword level interference cancellation (CW-IC) to know whether an interfering transport block (TB) is a new transmission or retransmission. With this knowledge, the UE knows whether the soft channel bits stored in a soft buffer are to be discarded or combined with the soft channel bits newly obtained.

Soft packet combining for superposition coding

An enhanced connection recovery upon lost RRC connection due to radio link failure (RLF) or handover failure (HOF) is proposed. A UE first establishes an RRC connection in a source cell in a mobile communication network. Later on, the UE detects a failure event and starts an RRC reestablishment procedure in a target cell to restore the RRC connection. In a first novel aspect, a fast RLF process is applied to reduce the outage time in the serving cell. In a second novel aspect, an enhanced cell selection mechanism based on cell prioritization information is applied to reduce the outage time in the target cell. In one embodiment, multi-RAT registration is used to steer cell selection.

Method of enhanced connection recovery and cell selection

A wireless communication system is provided that includes a base station receiving a plurality of input signals that are selectively provided to a plurality of precoders. The precoders perform precoding operations on the input signals and output a first signal. The base station includes an algorithm that minimizes total transmit power per antenna under signal to interference and noise ratio (SINR) target constraints or maximizes the SINR under a sum of power constraint so as to determine power allocation and obtain efficient precoders. A number of mobile receiver units receive the first signal and performs their respective operations to extrapolate the linear estimate of the input signals.

Non-codebook based precoding for multi-user MIMO downlink

An enhanced connection recovery upon lost RRC connection due to radio link failure (RLF) or handover failure (HOF) is proposed. A UE first establishes an RRC connection in a source cell in a mobile communication network. Later on, the UE detects a failure event and starts an RRC reestablishment procedure in a target cell to restore the RRC connection. In a first novel aspect, a fast NAS recovery process is applied to reduce the outage time in the target cell. In a second novel aspect, context fetching is used to reduce the outage time in the target cell. In a third novel aspect, a loss-less reestablishment procedure is proposed to reduce data loss during the connection recovery.

Method of enhanced connection recovery and loss-less data recovery

A method of transmitting extra spatial layers over a wireless channel is proposed. In one exemplary embodiment, the invention is directed to a method for scheduling higher number of layers than the preferred number reported from a mobile. In one exemplary embodiment, the invention is directed to a method for reporting multiple precoding candidates for the rank that is higher than the preferred rank reported from a mobile. In one exemplary embodiment, the invention is directed to a method for appending extra columns in the precoding matrix for the extra layers that a base station transmits. In one exemplary embodiment, the invention is directed to a method for transmitting extra data streams on the same wireless channel. In one exemplary embodiment, the invention is directed to a method for saving battery power utilizing the extra layers.

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Lexington, MA, United States of America

Tze-Ping Low