Techniques are provided herein to allow a wireless network access point (AP) to more fully use its bandwidth in order to leverage the different bandwidth capabilities of different types of wireless client devices that the AP serves. The AP generates control parameters for usage of a plurality of channels in a bandwidth during a downlink transmission interval. The control parameters comprise information indicating channel assignments that result in multiple downlink transmissions that at least partially overlap in time to different wireless client devices according to their respective bandwidth capabilities. The AP transmits the control parameters in a control frame in advance of the downlink transmission interval on each of the plurality of channels in the bandwidth.

Downlink OFDMA for service sets with mixed client types

The effects of adjacent channel interference (ACI) on WCDMA capacity are analyzed in the case of two operators allocated on adjacent radio channels or in the case of a single operator that uses two adjacent radio channels in a hierarchical cell structure. In contrast to existing literature, where ACI effects on system performance are generally evaluated by simulation, we propose a semi-analytical approach. The basic hypothesis is to model the ACI as a Gaussian random variable whose statistics, mean and variance, are obtained through simple and very fast simulation. Subsequently, the obtained statistics are used to calculate the outage probability using closed form equations. The advantage of this approach is that many different operating conditions can be analyzed with reduced computer calculation time as compared to the full Monte-Carlo method. Several performance results obtained by the application of the proposed approach are reported in the uplink case. Results are in very good agreement with those already presented in 3GPP reports.

A semi-analytic approach for CDMA systems performance evaluation with adjacent channel interference

The evolution of a WCDMA uplink modulation scheme is presented. Modulation schemes are analyzed from the power amplifier implementation point of view by comparing the RF envelopes of various modulation schemes. The power amplifier linearity requirements of different modulation schemes are compared using a measured class AB power amplifier. One of the challenges in WCDMA is the implementation of the transmitter for a WCDMA terminal supporting both speech and high-speed data. This paper proposes a transmitter architecture for optimizing the current consumption of the WCDMA terminal in both modes.

WCDMA uplink modulation scheme evolution and transmitter implementation

Over the last decade, the growth of second generation (2G) digital communications has been explosive. Now wireless communications is evolving to third generation (3G),where it will offer wideband data services and multimedia wideband products and services such as video conferencing and high speed Internet over a mobile phone. Amid these high-tech feature packed mobile devices, there is a major bottleneck of cost. The major cost factor in mobile devices is battery life.

A reconfigurable root raised cosine filter for a mobile receiver

In 3/sup rd/ generation cellular systems using WCDMA radio access technology (RAT) one operator could theoretically operate it's network by using only one frequency when another operator in the same area uses the immediate adjacent frequency. Then, on contrary to other systems, the adjacent channel interference (ACI) is coming entirely from another operator. Since most likely the network plans will be completely independent, the only means to combat this ACI is applying appropriate filters. This paper shows results on a study of the influence of 2 macro operators using WCDMA RAT in the same area in adjacent channels, by applying the filter values specified in 3GPP TS 25.101and 3GPP TS 25.104 . Two cases, one from an urban and one from a suburban area are shown. Example results on outage, coverage probabilities, quality of service, transmit power distributions etc. are presented with and without the second operator present and compared with each other. In conclusion of the comparison it is shown, that in macro cellular scenarios the influence of both operators on each other is negligible.

Mutual impact of two operators' WCDMA radio networks on coverage, capacity and QoS in a macro cellular environment

In this paper the effects of adjacent channel interference on WCDMA capacity are studied for two adjacent frequency operators as well as for a hierarchical cell structure to be used by one operator at adjacent frequency channels. The effect of adjacent channel interference on the system capacity is studied with practical loading of the WCDMA system. Also a new model for adjacent channel interference in the uplink is introduced taking into account the behaviour of a practical WCDMA terminal power amplifier. A goal of this paper is to find out the adjacent channel interference requirements for the WCDMA system.

H. Lilja

Papers

WCDMA adjacent channel interference requirements