A combined power/rate control scheme for data transmission over a DS/CDMA system

Hashem, B.; Sousa, E.S.

doi:10.1109/vetec.1998.686409

Cited by 18 publications

(9 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Instead of increasing the transmission power, the transmission rate can be decreased. Duan et al (2002); Hashem and Sousa (1998); Kim and Lee (2000); Oh and Wasserman (2003) and Kim and Honig (2000) use this idea.…”

Section: Resource Control Approachesmentioning

confidence: 99%

Uplink Load in CDMA Cellular Radio Systems

Lundin

Gunnarsson

2006

IEEE Trans. Veh. Technol.

View full text Add to dashboard Cite

The uplink of code division multiple access (CDMA) cellular radio systems is often interference limited. The interference originates from many users whose transmission powers are not observable for the system. This thesis introduces uplink load and applies means of explicitly considering the users' radio environment when approximating and controlling the load.A desirable property of all cellular radio systems is uplink feasibility, i.e., existence of finite user transmission powers to support the allocated services. Uplink load can be considered as a measure of how far from infeasibility the system is. The performed characterization of uplink load lead to two concrete definitions related to the amount of received and transmitted power, respectively.An important part of the total load is the intercell load which is caused by users connected to neighboring base stations. If not carefully handled, the intercell load can jeopardize uplink feasibility. Conversely, knowledge of a lower intercell load can be used to increase the resource assignments. A common denominator in all the work in this thesis is that the intercell load is explicitly considered.When approximating uplink load, a centralized approach is adopted to study information gathered in several base stations. This yields good approximations of the average load. However, centralized approximations can not detect momentarily peaks in the load. A number of resource allocation algorithms making control decisions in the local base stations are proposed based on experience from characterizing uplink load. As the algorithms study the intercell load, yet without measuring the interference power, they are robust in the sense that they will never assign resources yielding an infeasible system.A straightforward way of controlling the uplink load is to use measurements of the received interference power. This approach, just as the proposed load approximations, can gain from knowing the background noise power. The same framework used for designing robust resource allocation algorithms, is also used for estimating the background noise power. v vi AcknowledgmentsSo these are the words of this thesis that will be read by the most people. The probability of me forgetting someone is certainly high, but I'll give it a go anyway.First of all, the man who I got to know when he helped me every Tuesday, the whole day that is, during my master thesis, Dr. Fredrik Gunnarsson. Since then, he has excellently guided me through my time as a PhD student, without cutting down on those 20% of the work week. I am forever grateful for giving me exactly enough help to develop both my self and research results and never turning me down even when disturbing him at the Ericsson office. I don't know how many times he has read half done work, which I claimed was ready for publishing.Since I never moved out of the office room I was first placed in, I have had the pleasure of having Professor Fredrik Gustafsson next door ever since I joined the automatic control group. This has made it eas...

show abstract

Section: Resource Control Approachesmentioning

confidence: 99%

Uplink Load in CDMA Cellular Radio Systems

Lundin

Gunnarsson

2006

IEEE Trans. Veh. Technol.

View full text Add to dashboard Cite

show abstract

“…Therefore, when , i.e., should be limited by . However, since the probability of is negligibly small for parameter values of practical interests, (9) yields the actual average data rate.…”

Section: System Model and Analysismentioning

confidence: 99%

“…In [8], the optimization is performed with a maximum transmission power and a minimum rate requirement. In [9], a combined power/rate control scheme is considered that limits the increase in power by some fixed value and gets the extra gain required by reducing the rate.…”

Section: Introductionmentioning

confidence: 99%

Combined rate and power adaptation in DS/CDMA communications over Nakagami fading channels

Kim

Lee²

2000

IEEE Trans. Commun.

View full text Add to dashboard Cite

Abstract-We consider combined rate and power adaptations in direct-sequence code-division multiple-access communications, where the transmission power and the data rate are adapted relative to channel variations. We discuss the power gain that the combined adaptations provide over power adaptation. Then, we consider an integrated voice and data transmission system that offers a constant bit rate voice service, using power adaptation and a variable bit rate data service with rate adaptation. We present an expression for the required average transmission power of each traffic type having different quality-of-service specifications and discuss the capacity gain over power adaptation for voice and data.Index Terms-Combined rate and power adaptation, DS/CDMA, Nakagami fading.

show abstract

“…A combined power and rate adaptation scheme has been proposed for direct-sequence code-division multiple-access (DS/CDMA) systems over the Rayleigh-fading channels in [1] and over the Nakagami-fading channels in [2]. Under a deep fade, when the transmitted power has been increased to a preassigned maximum level, a further gain in performance can be obtained by reducing the data rate.…”

Section: Introductionmentioning

confidence: 99%

“…Under a deep fade, when the transmitted power has been increased to a preassigned maximum level, a further gain in performance can be obtained by reducing the data rate. It was shown in [1] that a substantial increase in the aggregate users data transmission rate can be achieved while in [2], a substantial increase in power gain can be realized, over the power only adaptation scheme.…”

Section: Introductionmentioning

confidence: 99%

Combined power and rate adaptation for wireless cellular systems

Chai

Tjhung

Leck³

2005

IEEE Trans. Wireless Commun.

View full text Add to dashboard Cite

We extend the throughput optimization technique of Qiu and Chawla for adaptive modulation, to combine power and rate adaptation in wireless cellular systems. We develop new combined power and rate control algorithms for wireless multimedia systems, in which the transmitted powers and rates of different media users are adapted based on the signal-to-interference power ratio. Using simulations, we show that with appropriately chosen power and rate limits, our proposed combined power and rate control algorithms can achieve a higher throughput when compared to previously proposed algorithms with power control only.

show abstract

A combined power/rate control scheme for data transmission over a DS/CDMA system

Cited by 18 publications

References 6 publications

Uplink Load in CDMA Cellular Radio Systems

Uplink Load in CDMA Cellular Radio Systems

Combined rate and power adaptation in DS/CDMA communications over Nakagami fading channels

Combined power and rate adaptation for wireless cellular systems

Contact Info

Product

Resources

About