Johan Sköld

FRAMES multiple access mode 1-wideband TDMA with and without spreading

An evaluation of several multiple access schemes against UMTS criteria has been carried out within the European FRAMES project. Based on this comprehensive evaluation, a harmonised radio interface termed FRAMES multiple access (FMA) has been designed consisting of two operating modes: a wideband TDMA mode with and without spreading (FMA1), and a wideband CDMA mode (FMA2). This paper describes the FMA1 radio access system proposal. The FMA2 proposal is described in Ovesjo et al.

Background of LTE

This chapter provides a historical overview of the evolution of mobile communication from the first generation of analog cellular systems, through second generation (2G) systems such as GSM and 3G systems including WCDMA/HSPA, into 4G LTE. ITU and its activities related to IMT and IMT-Advanced are described, as is the process in 3GPP, the organization responsible for developing the GSM, WCDMA/HSPA, and LTE technical specifications.

A Simplified Approach to Applying the 3GPP Spatial Channel Model

This paper reports on a set of channel models that have been proposed for the evaluation of system concepts for the long-term evolution of third generation mobile communications systems. Conflicting requirements between simplicity of implementation and accuracy in reproducing the radio channel are presented, and the resulting modeling choices are discussed. The channel models have been derived by combining a spatial channel model with several different antenna arrangements that are envisioned to be typical for the systems in question. These antenna arrangements include both spatial separation of elements and polarization. The channel models are supplied as tapped delay lines with correlation parameters for simulating full MIMO channels of size up to 4times4

LTE physical layer

Publisher Summary This chapter describes lowest of the protocol layers of the Long-Term Evolution (LTE) radio-interface architecture, the LTE physical layer. It provides detailed information on processing and control signaling for the orthogonal frequency division multiplex (OFDM) downlink transmission and the Single-Carrier frequency division multiple access (FDMA) uplink. The chapter begins with a discussion on the overall time-domain structure for LTE transmission. This is followed by LTE downlink transmission scheme, which is based on OFDM. The basic LTE downlink physical resource can be seen as a time-frequency resource grid, where each resource element corresponds to one OFDM subcarrier during one OFDM symbol interval. Finally, the chapter describes the LTE uplink transmission scheme, which is based on so-called DFTS–OFDM transmission. DFTS–OFDM is a low-PAR “single-carrier” transmission scheme that allows for flexible bandwidth assignment and orthogonal multiple access not only in the time domain but also in the frequency domain. Thus, the LTE uplink transmission scheme is also referred to as “single-carrier FDMA (SC-FDMA).” LTE uplink transmission is limited to localized transmission.

Chapter 14 – Access Procedures

Publisher Summary This chapter describes the procedures necessary for a terminal to be able to access an LTE-based network. Before an LTE terminal can communicate with an LTE network, it has to find and acquire synchronization to a cell within the network; and receive and decode the information, also referred to as the cell system information, needed to communicate with and operate properly within the cell. The first of these steps, simply referred to as cell search, includes acquisition of frequency and symbol synchronization to a cell; acquisition of frame timing of the cell; and determination of the physical-layer cell identity of the cell. There are 504 different physical-layer cell identities defined for LTE, where each cell identity corresponds to one specific downlink reference-signal sequence. The set of physical-layer cell identities is further divided into 168 cell-identity groups, with three cell identities within each group. This chapter begins with an overview of LTE cell search, PSS structure and SSS structure. The chapter then discusses the basic concepts of MIB and BCH transmission and system-information blocks. The chapter concludes with a discussion on terminal identification, contention resolution, and paging.

Scheduling and Rate Adaptation

This chapter discusses the key radio-resource-management functionality relevant for LTE, including downlink and uplink scheduling and reporting of channel-state information.

Downlink Physical-Layer Processing

This chapter provides a detailed description of the LTE downlink physical-layer functionality, including transport-channel processing, downlink reference signals, details on downlink multi-antenna transmission, and control signaling.

Radio-Interface Architecture

Abstract This chapter described the overall NR architecture. DIfferent alternatives for connecting the NR RAN to the core netwrok (EPC or 5GCN) are discussed. The overall protocol structure and the different channel types are also outlined.

New 5G Radio-Access Technology

This chapter goes more into the details of the new 5G radio-access technology to be developed by 3GPP. It begins with a discussion of some key design principles that needs to be followed in order to ensure a high performance, flexible, and future proof air interface. It then goes more into the details on the key 5G technology components including but not limited to duplex arrangement, 5G waveform, massive MIMO, multi-site connectivity, flexible system plane, and access/backhaul integration.

Multimedia Broadcast/Multicast Services

In the past, cellular systems have mostly focused on transmission of data intended for a single user and not on broadcast services. Traditional broadcast networks, exemplified by the radio and TV broadcasting networks, have on the other hand focused on covering very large areas and have offered no or limited possibilities for transmission of data intended for a single user. Multimedia Broadcast and Multicast Services (MBMS), introduced for WCDMA in release 6, supports multicast/broadcast services in a cellular system, thereby combining multicast and unicast transmissions within a single network. With MBMS, the same content is transmitted to multiple users located in a specific area, the MBMS service area , in a unidirectional fashion. The MBMS service area typically covers multiple cells, although it can be made as small as a single cell. In this chapter, the principles behind MBMS in the radio access network and their introduction into WCDMA are discussed.