A system and method are described which enable planned evolution and obsolescence of multiuser wireless spectrum. One embodiment of such a system includes one or multiple centralized processors and one or multiple distributed nodes that communicate via wireline or wireless connections. The distributed nodes may share their identification number and other reconfigurable system parameters with the centralized processor. The information about all distributed nodes may be stored in a database that is shared by all centralized processors. The reconfigurable system parameters may comprise power emission, frequency band, modulation/coding scheme. The distributed nodes may be software defined radios such as FPGA, DSP, GPU and/or GPCPU that run algorithms for baseband signal processing and may be reconfigured remotely by the centralized processor. A cloud wireless system may be used wherein the distributed nodes are reconfigured periodically or instantly to adjust to the evolving wireless architecture.

System and methods for planned evolution and obsolescence of multiuser spectrum

Range expansion and inter-cell interference coordination (ICIC) can improve the capacity and fairness of heterogeneous network (HetNet) deployments by off-loading macrocell users to low-power nodes. Due to difficulties in analytical treatment, current studies for range expansion and ICIC in HetNets rely mostly on simulations. In this letter, first, off-loading benefits of range expansion in HetNets are captured through cumulative distribution functions (CDFs) of the downlink signal to interference plus noise ratio (SINR) difference between the macrocell and strongest picocell signals. Then, these CDFs are used to investigate the system capacity and fairness as a continuous function of the range expansion bias, and benefits of using ICIC with range expansion are demonstrated through numerical results.

Capacity and Fairness Analysis of Heterogeneous Networks with Range Expansion and Interference Coordination

A system and methods are described which compensate for the adverse effect of Doppler on the performance of DIDO systems. One embodiment of such a system employs different selection algorithms to adaptively adjust the active BTSs to different UEs based by tracking the changing channel conditions. Another embodiment utilizes channel prediction to estimate the future CSI or DIDO precoding weights, thereby eliminating errors due to outdated CSI.

System and methods to compensate for Doppler effects in multi-user (MU) multiple antenna systems (MAS)

The present invention relates to a method for receiving a downlink control signal in a TDD-based wireless communication system, and to an apparatus therefor. The method comprises receiving a downlink signal via a downlink interval in a specific frame including the downlink interval, a guard interval and an uplink interval. A combination of the downlink interval, the guard interval and the uplink interval is given using configuration information on the specific subframe. When the configuration information is given such that the length of the downlink interval is larger than a specific value, detecting a first type of PDCCH is performed in the specific subframe. When the configuration information is given such that the length of the downlink interval is equal to or smaller than the specific value, detecting the first type of PDCCH is skipped in the specific subframe.

Method and apparatus for transmitting control information in wireless communication system

A user terminal according to an embodiment comprises: a transmitter configured to transmit a message to a base station, the message requesting a gap used to receive or transmit a discovery signal that is a direct terminal-to-terminal radio signal for discovering another user terminal; and a receiver configured to receive configuration information from the base station, the configuration information configuring the gap to the user terminal. The message includes: gap information indicating the gap; and frequency information indicating a frequency associated with the gap information. The gap information includes: a bitmap indicating at least one subframe; and an offset value with reference to “0” of system frame number (SFN).

User terminal and base station

Deploying Pico eNodeBs (PeNBs) throughout a Macro cell layout is a promising solution to enhance system capacity and user throughput. However, strong received power from Macro eNodeBs (MeNBs) makes the Pico cell areas narrow. This causes limited cell splitting gain. Cell Range Expansion (CRE), which allows a User Equipment (UE) to be served by a cell with weaker received power, is simple and typical one of alternative cell associations to enhance offloading but it causes downlink (DL) interference issue in not only data and also control channels (CCHs). In this paper, we investigate performance of CRE with various bias settings and show that a moderate bias setting is effective to enhance capacity and user throughput. With respect to the DL interference issue in CCHs, we propose to support coordination of Lightly Loaded CCH transmission Subframe (LLCS) in LTE-Advanced.

Pico Cell Range Expansion with Interference Mitigation toward LTE-Advanced Heterogeneous Networks

A picocell base station (PeNB) uses a downlink control channel, the frequency band of which overlaps with the frequency band of the downlink control channel used by a macrocell base station (MeNB), to transmit downlink control information for controlling wireless communication with a wireless terminal (PUE) connected to the picocell base station (PeNB). The picocell base station (PeNB) comprises an X2 interface communication unit (140) which uses inter-base station communication to transmit to the macrocell base station (MeNB) usage amount control information for controlling the control channel usage amount that is the usage amount of a wireless resource used as the downlink control channel by the macrocell base station (MeNB).

Wireless communication system, wireless base station, and communication control method

A radio communication system (1) includes a pico-cell base station (PeNB,) which is located in the communication area of a macro-cell base station (MeNB) and the transmission power of which is lower than that of the macro-cell base station (MeNB) . For radio resources that can be used as PDSCH, a resource division ratio that is a ratio between unusable PDSCH resources, which cannot be used by the macro-cell base station (MeNB), and usable PDSCH resources, which can be used by the macro-cell base station (MeNB), is decided, and a radio resource is allocated, out of the usable PDSCH resources defined in accordance with the decided resource division ratio, to a radio terminal that is to connect to the macro-cell base station (MeNB). The resource division ratio is decided based on the traffic load of each base station.

Wireless communication system, high power base station, low power base station and communication control method

When receiving a signal from the antenna # 1 (initially receiving a signal from an omnidirectional antenna), a guard interval correlator 12 calculates correlation of a guard interval portion of the received signal and an output measuring unit 13 measures a peak output of the guard interval correlator 12 . A comparator 14 compares the peak output measured by the output measuring unit 13 with a preset threshold, and when the peak output falls below the preset threshold and outputs an antenna switching control signal to an antenna switch 11 , and the antenna switch 11 switches to the antenna # 2 having a different directivity.

Reception control method and wireless communication apparatus

A radio communication system 1 includes a pico-cell base station PeNB installed in a communication area of a macro-cell base station MeNB, having lower transmission power than the macro-cell base station MeNB, and expanded in its coverage. The macro-cell base station MeNB determines a degree of expanding the coverage of the pico-cell base station PeNB, according to an amount of usable PDSCH resources of the macro-cell base station MeNB.

Kenta Okino

Papers

Pico Cell Range Expansion with Interference Mitigation toward LTE-Advanced Heterogeneous Networks

Wireless communication system, wireless base station, and communication control method

Wireless communication system, high power base station, low power base station and communication control method

Reception control method and wireless communication apparatus

Radio communication system, high-power base station, low-power base station, and communication control method