Feasibility study for Orthogonal Frequency Division Multiplexing (OFDM) for UTRAN enhancement
The scope of this Study Item is to consider the performance of OFDM in the mobile environment and to consider scenarios in which OFDM may be introduced in UTRAN 3GPP based systems. This activity involves the Radio Access work area of the 3GPP studies and has some effect on the Mobile Equipment and Access Network of the 3GPP systems.
The aims of this study are:
- to consider the advantages that may be gained by introducing a new modulation technique in 3GPP RAN systems,
- to estimate possible benefits and complexity and
- to recommend to 3GPP RAN if further standardisation development work should be undertaken by 3GPP.
As a starting point, OFDM will be considered in the downlink only. It should be possible to operate in a 5MHz spectrum allocation i.e. coupled with W-CDMA in the uplink for a 2*5MHz deployment scenario.
The following list provides examples of areas that are to be considered in the study:
- Throughput for data services . To be compared with throughput of current UTRAN releases;
- Complexity aspects of multimode UEs supporting both OFDM and release 99/release 5 UMTS;
- Deployment scenarios including frequency re-use aspects within diverse spectrum allocations;
The study should consider performance aspects, aspects linked to the evolution of UMTS (high level architecture, diverse spectrum arrangements and allocations), impacts on signalling in UTRAN , aspects of capacity/cost/complexity/coverage and aspects of co-existence with the existing UMTS modes.
The purpose of the study is to consider the feasibility of introducing OFDM in UTRAN and to compare OFDM performance with HSDPA. The analysis of OFDM performance and its comparison with reference HSDPA performance should be based on a basic OFDM design (often referred as textbook OFDM). More elaborate OFDM techniques should not be considered. However the use of text book OFDM in the feasibility study phase does not restrict the design when moving to the specification phase. It is a study of physical layer aspects only and does not include changes in UTRAN architecture. Changes are to be restricted to the physical layer and not extend beyond those needed to support an additional modulation. Principles as provided in TS 25.302 (Services provided by the physical layer) are to be respected where possible.
This study item was approved by the TSG RAN#16 (Marco Island Fl USA 4th – 7th June 2002).