Per Beming

WCDMA-the radio interface for future mobile multimedia communications

This paper presents the wide-band code-division multiple-access (WCDMA) radio interface chosen by the ETSI as the basic radio-access technology for the universal mobile telecommunications system (UMTS). A detailed description of the physical layer of ETSI WCDMA is given together with an overview UMTS of the higher layers of the WCDMA radio interface. Finally, the WCDMA performance, based on results from the ETSI evaluation of UMTS radio interface candidates, is presented.

The evolution of WCDMA towards higher speed downlink packet data access

The first step of evolving WCDMA towards higher data rates is discussed. It is shown how techniques such as fast link adaptation, fast hybrid ARQ and fast scheduling, among others, can be applied to WCDMA, leading to increased throughput, lower delays, and downlink peak rates in the order of 10 Mbit/s. Through system simulations, the packet-data performance of such an evolved WCDMA system is illustrated.

The high speed packet data evolution of WCDMA

The first step of evolving WCDMA towards higher data rates through the introduction of HSDPA is discussed. By applying fast link adaptation together with higher order modulation, fast hybrid ARQ and fast scheduling, the best-effort packet data support of WCDMA can be improved in terms of increased throughput, lower delays and increased peak data rates. Simulations illustrate the potential of the concept.

A proposal for an RLC/MAC protocol for wideband CDMA capable of handling real time and non-real time services

In this paper we describe a proposal for a radio link control/medium access control (RLC/MAC) protocol for a W-CDMA system. It makes use of the flexibility offered by the physical layer in the sense that it supports variable bit rate services. In addition the RLC/MAC is designed such that multiple services are supported, without the necessity to transmit with multiple spreading codes.

Beyond 3G radio access network reference architecture

Today a multitude of radio access technologies exist and are continuously evolved to support higher bit rates, lower delays, lower cost, etc. In addition, new radio access technologies are developed to complement those of today. When using services in this environment with multiple radio access technologies, end users expect mobility between the different radio access technologies to be seamless. Network operators, in addition, look for efficient resource usage of different radio access technologies and more cost efficient ways to deploy networks. This requires increased flexibility in the radio access network architecture compared with todays architectures. In this paper a beyond 3G radio access network reference architecture supporting these requirements is presented. The architecture allows for various implementations and considers new deployment concepts such as multi-hop radio networks, moving networks and personal area networks.

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.

Enhancing Packet Data Access in WCDMA

In this paper, the first step of evolving WCDMA beyond IMT-2000 is outlined and elaborated upon. It is shown how techniques such as fast link adaptation, fast hybrid ARQ and fast scheduling, among others, can be applied to WCDMA, leading to increased throughput for best-effort services, lower delays, and downlink peak rates in the order of 10 Mbit/s. The end-to-end protocol architecture is discussed, and using protocol simulations the benefit of having a hybrid type II ARQ scheme in Node B is shown.

1 – Background of 3G evolution

This chapter reviews a journey of the mobile communication right from the beginning, before 3G, to the present state. To understand the complex 3G mobile-communication systems of today, it is important to understand where they came from. Also, it is essential to know how cellular systems have evolved from an expensive technology to todays global mobile-communication systems. Developing mobile technologies have also changed, from being a national or regional concern, to becoming a very complex task undertaken by global standards developing organizations such as the Third Generation Partnership Project (3GPP). It all began several decades ago with early deployments of analog cellular services. Furthermore, the chapter discusses the standardization process for mobile communication. It is not a one-time job but an ongoing process. The standardization forums are constantly evolving their standards trying to meet new demands for services and features. The standardization process is different in the different forums, but typically includes the four phases: requirements, architecture, detailed specifications, and testing and verification. Finally, the chapter explores the spectrum for 3G.

18 – System Architecture Evolution

This chapter provides an overview of the System Architecture Evolution (SAE) work in 3GPP and explores the core network used by WCDMA/ High-Speed Packet Access (HSPA)The chapter describes the system architecture of WCDMA/HSPA and Long-Term Evolution (LTE), their connections, similarities, and differences. The term system architecture describes the allocation of necessary functions to logical nodes and the required interfaces between the nodes. The system architecture is divided into a radio-access network (RAN) part and a core-network part. The chapter discusses the functional split between radio access network and core network. For WCDMA/HSPA, the philosophy behind the functional split is to keep the core network unaware of the radio access technology and its layout. This means that the RAN should be in control of all functionality optimizing the radio interface and that the cells should be hidden from the core network. As a consequence, the core network can be used for any radio access technology that adopts the same functional split.

The motives behind the 3G evolution

This chapter highlights some of the driving forces behind the 3G evolution, giving the reader an understanding of where the technical requirements and solutions are coming from. A key factor for success in any business is to understand the forces that will drive the business in the future. This is in particular true for the mobile-communication industry. Here the rapid growth of the number of subscribers and the global presence of the technologies have attracted several new players that want to be successful. The chapter also discusses Radio Access Network (RAN) approaches and an evolved core network with regard to the 3G evolution, In addition to Long-Term Evolution (LTE) and high-speed packet access (HSPA).An evolved core network, the “Evolved Packet Core,” was developed to ensure that an operator can coexist easily between HSPA Evolution and LTE. The System Architecture Evolution (SAE) study focused on how the 3GPP core network will evolve into the core network of the next decades. The philosophy of the SAE is to focus on the packet-switched domain and migrate away from the circuit-switched domain. This is done through the coming 3GPP releases ending up with the Evolved Packet Core.