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An LTE Transmitter Using a

Class-A/B Power Mixer[1]Using for Custom Implementation of DSP systems class presentation.

Presented by: Nader Sehatbakhsh

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Outline

• History of mobile communications and generations

• 4th generation and LTE• LTE transmitter architecture in details• Results• Conclusion

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History of Mobile Systems

• The advances in mobile telephony can be traced in successive generations from the early "0G" services like MTS and its successor Improved Mobile Telephone Service, to first generation (1G) analog cellular network, second generation (2G) digital cellular networks, third generation (3G) broadband data services to the current state of the art, fourth generation (4G) native-IP networks.

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Evolution of Generations

Ref.[2]

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Fourth Generationo 4G is the fourth generation of mobile phone mobile communication

technology standards.o Two 4G candidate systems are commercially deployed: the Mobile

WiMAX standard (at first in South Korea in 2006), and the first-release Long Term Evolution (LTE) standard[5].

o 100 (Mbit/s) for high mobility communication and 1 (Gbit/s) for low mobility communication. (Derived form International Mobile Telecommunications Advanced (IMT-Advanced) specification).

o The spread spectrum radio technology used in 3G systems, is abandoned in all 4G candidate systems and replaced by OFDMA multi-carrier transmission, making it possible to transfer very high bit rates despite extensive multi-path radio propagation (echoes). The peak bit rate is further improved by smart antenna arrays for multiple-input multiple-output (MIMO) communications.

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LTE• LTE is a standard for wireless data communications

technology and an evolution of the GSM/UMTS standards.

• The goal of LTE was to increase the capacity and speed of wireless data networks using new DSP (digital signal processing) techniques and modulations that were developed around the turn of the millennium.

• A further goal was the redesign and simplification of the network architecture to an IP-based system with significantly reduced transfer latency compared to the 3G architecture[4].

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LTE Design Challenges

Ref.[1]

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Transmitter Block Diagram

Ref.[1]

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DAC and Biquad Section

Ref.[1]

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V to I Converter

Ref.[1]

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Class AB Mixer Driving

Ref.[1]

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Mixer Transconductor Driver

Ref.[1]

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Power Mixer

Ref.[1]

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Die Photograph

Ref.[1]

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TX Performance Comparison

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Conclusion• Viability of class AB power mixer transmitters for

wireless application• Well suited for high PAR signals that

characterize the new generation mobile standards

• Widely configurable and programmable TX to fulfill cellular requirements for smartphone platforms

• TX part of a Fully Integrated transceiver ready for massive production

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References[1] Paolo Rossi et al. , “An LTE Transmitter Using a Class-A/B Power Mixer,” ISSCC Dig. Tech. Papers, pp. 340– 341, Feb. 2013.[2] Simon Forge, “Is fourth generation mobile nirvana or … nothing?,” info Emerald, Vol. 6 Iss: 1, pp.12-23.[3] O. Oliaei et al. “A Multiband Multimode Transmitter Without Driver Amplifier” ISSCC Dig. Tech. Papers, pp.164-166, Feb. 2012.[4] "Long Term Evolution (LTE): A Technical Overview". Motorola. Retrieved May 9, 2013.[5] http://en.wikipedia.org/wiki/4G retrieved on May 9, 2013