Wireless Communications

A cellular base station serves a multiplicity of single-antenna terminals over the same time-frequency interval. Time-division duplex operation combined with reverse-link pilots enables the base station to estimate the reciprocal forward- and reverse-link channels. The conjugate-transpose of the channel estimates are used as a linear precoder and combiner respectively on the forward and reverse links. Propagation, unknown to both terminals and base station, comprises fast fading, log-normal shadow fading, and geometric attenuation. In the limit of an infinite number of antennas a complete multi-cellular analysis, which accounts for inter-cellular interference and the overhead and errors associated with channel-state information, yields a number of mathematically exact conclusions and points to a desirable direction towards which cellular wireless could evolve. In particular the effects of uncorrelated noise and fast fading vanish, throughput and the number of terminals are independent of the size of the cells, spectral efficiency is independent of bandwidth, and the required transmitted energy per bit vanishes. The only remaining impairment is inter-cellular interference caused by re-use of the pilot sequences in other cells (pilot contamination) which does not vanish with unlimited number of antennas.

Noncooperative Cellular Wireless with Unlimited Numbers of Base Station Antennas

Multiple-input multiple-output (MIMO) technology is maturing and is being incorporated into emerging wireless broadband standards like long-term evolution (LTE) [1]. For example, the LTE standard allows for up to eight antenna ports at the base station. Basically, the more antennas the transmitter/receiver is equipped with, and the more degrees of freedom that the propagation channel can provide, the better the performance in terms of data rate or link reliability. More precisely, on a quasi static channel where a code word spans across only one time and frequency coherence interval, the reliability of a point-to-point MIMO link scales according to Prob(link outage) ` SNR-ntnr where nt and nr are the numbers of transmit and receive antennas, respectively, and signal-to-noise ratio is denoted by SNR. On a channel that varies rapidly as a function of time and frequency, and where circumstances permit coding across many channel coherence intervals, the achievable rate scales as min(nt, nr) log(1 + SNR). The gains in multiuser systems are even more impressive, because such systems offer the possibility to transmit simultaneously to several users and the flexibility to select what users to schedule for reception at any given point in time [2].

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Scaling Up MIMO: Opportunities and Challenges with Very Large Arrays

The quintessential goal of sensor array signal processing is the estimation of parameters by fusing temporal and spatial information, captured via sampling a wavefield with a set of judiciously placed antenna sensors. The wavefield is assumed to be generated by a finite number of emitters, and contains information about signal parameters characterizing the emitters. A review of the area of array processing is given. The focus is on parameter estimation methods, and many relevant problems are only briefly mentioned. We emphasize the relatively more recent subspace-based methods in relation to beamforming. The article consists of background material and of the basic problem formulation. Then we introduce spectral-based algorithmic solutions to the signal parameter estimation problem. We contrast these suboptimal solutions to parametric methods. Techniques derived from maximum likelihood principles as well as geometric arguments are covered. Later, a number of more specialized research topics are briefly reviewed. Then, we look at a number of real-world problems for which sensor array processing methods have been applied. We also include an example with real experimental data involving closely spaced emitters and highly correlated signals, as well as a manufacturing application example.

Two decades of array signal processing research: the parametric approach

It is shown that, particularly for terrestrial cellular telephony, the interference-suppression feature of CDMA (code division multiple access) can result in a many-fold increase in capacity over analog and even over competing digital techniques. A single-cell system, such as a hubbed satellite network, is addressed, and the basic expression for capacity is developed. The corresponding expressions for a multiple-cell system are derived. and the distribution on the number of users supportable per cell is determined. It is concluded that properly augmented and power-controlled multiple-cell CDMA promises a quantum increase in current cellular capacity. >

On the capacity of a cellular CDMA system

방법들 및 디바이스들이 물리 채널을 통한 데이터 송신과 관련된 미세 동기화를 가능하게 한다. 미세 타이밍 기준 신호가 때때로 수신자-특정 패턴의 시간-주파수 자원들 중 하나를 사용하여 데이터 송신 수신자에게 송신된다.

때때로 송신되는 미세 타이밍 기준 신호들로 동작하는 방법들 및 디바이스들

FIELD: wireless networks.SUBSTANCE: method contains the following steps: transmitting to the terminal (User Equipment, hereinafter - UE) an indication of the active segment of the carrier bandwidth part (hereinafter – BWP) suitable for communication on the shared channel, selection of one or more frequency domain resource blocks (hereinafter – RB) within the BWP active segment for allocation to the UE terminal, encoding the indication of one or more selected blocks RB using the set of available bits, and the set of available bits is not enough to encode all combinations of blocks RB that can be allocated within the active segment of the BWP, transmitting the coded indication to the UE terminal on the downlink control channel.EFFECT: technical result is more efficient use of physical downlink control channel (hereinafter – PDCCH) in new radio technology (hereinafter – NR technology), resulting in improved resource allocation delay and an increase in the number of UE that can use the resources of a specific PDCCH; it is achieved by more efficient use of the bits available for signaling resource allocation.16 cl, 1 tbl, 25 dwg

Method for signaling frequency domain resources allocation

본 발명은 하나의 캐리어에 대해 다수의 구성 가능한 뉴머롤로지가 존재할 때 랜덤 액세스 절차들을 구성하거나 사전 구성하기 위한 방법들 및 장치들을 제안한다. 일부 실시예들에서, 무선 장치의 랜덤 액세스 뉴머롤로지는 시스템 정보 블록을 사용하여 구성된다. 다른 실시예들에서, 무선 장치에 의해 사용되는 랜덤 액세스 뉴머롤로지는 하나 이상의 동기 신호의 검출에 기초하여 암시적으로 결정된다.

다중 뉴머롤로지 연산을 위한 랜덤 액세스 방법

FIELD: physics.SUBSTANCE: invention relates to a method of operating user equipment in a radio access network, wherein user equipment is configured by a pool of transmission resources, wherein the transmission resource pool comprises resources for transmitting feedback by the user equipment in form of a hybrid automatic repeat request (HARQ). Method comprises a step of transmitting feedback in the form of a HARQ using a resource structure, wherein the resource structure is selected from a pool of transmission resources based on the signalling characteristic for the downlink control information (DCI) message, received by user equipment, wherein signalling characteristic is represented by resources in receiving resources pool, on which DCI message is received, wherein the resource structure is further selected based on the selection control information included in the DCI message.EFFECT: technical result consists in enabling reduced volume of transmitted service information.9 cl, 3 dwg

Selecting resources for control alarm in radio access network

This chapter provides a detailed description of the downlink and uplink physical-layer transport-channel processing including coding, modulation, multi-antenna precoding, resource-block mapping, and reference signal structure.

Stefan Parkvall

Papers

때때로 송신되는 미세 타이밍 기준 신호들로 동작하는 방법들 및 디바이스들

Method for signaling frequency domain resources allocation

다중 뉴머롤로지 연산을 위한 랜덤 액세스 방법

Selecting resources for control alarm in radio access network

Transport-Channel Processing