Литература / UMTS-Report

amplifier takes power even if the transmission power in small cells is very low. On the other hand, two or more amplifiers can be used to improve the efficiency at low output powers.

The power consumption of the A/D converter in the receiver and the D/A converter in the transmitter depends on the sampling frequency, on the word length requirements, and on the proportional time the converter is on/off during the operation. Factors affecting the word length requirements are e.g. the number of modulation levels or/and parallel codes, the performance of automatic gain control in fading channel and the required SIR. An approximate formula for calculation of ADC and DAC power consumption = sampling frequency / 1e8 *2^bits [mW]. Here it is assumed that the ADC and DAC power consumption together is 50 mW or less. For more exact values to be compared with other UMTS schemes, the word length requirements should be taken into account.

The power consumption of the synthesisers depends on the number of synthesisers needed. It is assumed that the power consumption of the synthesisers is 50 mW. This estimate is based on the power consumption of the current mobile terminals.

Table 4.5. Estimated total RF power consumption

4.3.6 Baseband vs. RF power consumption

The baseband power consumption should be compared to the power consumption of RF parts to find out which one is dominating in transmission mode. According to Table 4.5 the power consumption of RF parts at maximum output power is 500 mW or less. Therefore the baseband power consumption of Table 4.3 is significant compared to RF parts. For comparison, the power consumption of current GSM phones in talk mode at 250 mW average transmission power is typically 1500 mW including baseband, RF and all the other functions.

4.4 GSM/UMTS Dual mode terminal implementation

In the following table changes needed for the UMTS/GSM dual mode terminal are listed.

Table 4.6. The needed changes for UMTS terminals for dual mode UMTS/GSM operation

Source: SMG2

Concept Group Alpha -

Wideband Direct-Sequence CDMA (WCDMA)

EVALUATION DOCUMENT (3.0)

Part 3:

Detailed simulation results and parameters

In the procedure to define the UMTS Terrestrial Radio Access (UTRA), the wideband DS-CDMA concept group (Alpha) will develop and evaluate a multiple access concept based on direct sequence code division. This group was formed around the DS-CDMA proposals from FRAMES Mode 2, Fujitsu, NEC and Panasonic. The main radio transmission technology (RTT) and parameters of the common concept from the Alpha group along with performance results are presented in this document.

This document was prepared during the evaluation work of SMG2 as a possible basis for the UTRA standard. It is provided to SMG on the understanding that the full details of the contents have not necessarily been reviewed by, or agreed by, SMG2.

1. INTRODUCTION

This is the Part 3 of the Alpha (Wideband DS-CDMA) concept group evaluation document and presents detailed parameters and simulation result curves of the W-CDMA concept. This is a separate file for purely editorial reasons. This document contains two sections: link-level simulations and system-level simulations for the FDD mode.

In the sections with link-level simulations both detailed parameters used in each simulation and also curves with simulation results are presented. In system-level sections the detailed simulation parameters are presented. Also, some additional figures related to the sytem simulations are shown here.

2. LINK-LEVEL SIMULATIONS

In this section link-level simulation parameters for the different test cases are listed for the FDD mode, together with plots with simulation results. Note that the first row of each column in the parameter tables lists the number of the figure where the simulation result can be found.

2.1 Speech

Some improvements have been done to get better results than the previously presented values in Evaluation Document Draft 1.0. These improvements are due to:

∙For 20 ms interleaving, both the coding and interleaving is now performed over 20 ms which implies less overhead for CRC and convolutional coding tail.

∙Blind rate detection can be easily implemented since only two information bit-rates (0 and 8 kbps) are used and therefore the FCH bits can be used as pilot symbols.

∙For the Vehicular environment, a smaller power control step is used (now 0.25 dB, before 0.5 dB).

2.1.1 Indoor Office A, 3 km/h

Table 1. Parameters for speech Indoor A simulations.

2.1.2 Outdoor to Indoor and Pedestrian A, 3 km/h

Table 2. Parameters for speech Outdoor to Indoor A simulations.