You are here: silicon.com > Resources > White Papers > Desktops, Laptops and OS > Components > Modems

Modems White Papers

MIMO OFDM Receivers for Systems With IQ Imbalances

Overview Orthogonal frequency division multiplexing (OFDM) is a widely recognized modulation scheme for high data rate communications. However, the implementation of OFDM-based systems suffers from in-phase and quadrature-phase (IQ) imbalances in the front-end analog processing. Such imbalances are caused by the analog processing of the received radio frequency (RF) signal, and they cannot be efficiently or entirely eliminated in the analog domain. The resulting IQ distortion limits the achievable operating SNR at the receiver and, consequently, the achievable data rates. In this paper, the effect of IQ imbalances on multi-input multi-output (MIMO) OFDM systems is studied and a framework for combating such distortions through digital signal processing is developed.

Further White Paper Details
Publisher	Institute of Electrical and Electronics Engineers	File Format	PDF
Date Published	January 2005	Downloads	756
Format	White Papers
Topics	Modems, Mobile - Wireless Communications, Wireless LAN

Did you find this white paper useful? 6 out of 10 users found this white paper useful

The Ovum View: Speech - IT meets telephony?

Speech input and output to IT systems has passed the credibility threshold. A distributed processing approach is valuable for mobile applications so that the embedded system can continue processing when the user passes through areas of poor radio...

Channel:
Comment & Analysis

TI's 'turbo Wi-Fi' - still born?

In the 802.11g standards battle, PBCC eventually lost ground to OFDM, or Orthogonal Frequency Division Multiplexing, as the modem of choice. PBCC is one way for wireless networks to attach digital information to radio waves.

Channel:
PDAs

Peter Cochrane's Uncommon Sense: The right technology for the right job

And more recently wireless technology is becoming so low cost and so high performance that signal processing requirements for data over power cables, even if it were possible, would be prohibitively expensive in comparison.

The Bloor Perspective: Biometric choices, 3G+WLAN and EMC buying VMWare

Then there is the potential problem of frequency interference with Bluetooth. Over recent years, phones have become dual band, tri-band and even quad-band to cover an ever larger frequency range of countries with GSM networks.

Channel:
Storage

Radioactive: Bluetooth - survival of the fastest

The opposing technology approaches are orthogonal frequency division multiplexing (OFDM) and direct sequence (DS)-UWB. The former method, backed by Intel, is more complex: it chops up the signal and sends it over multiple frequency bands.

Complexity makes travellers miss their connection

In the not too distant future, you will be able to add 3G Long Term Evolution (LTE), mobile WiMax, multiple in multiple out (MiMo) and orthogonal frequency division multiplexing (OFDM) to the mix. The exception is 3, which offers roaming on its...

Live Webcast: Telecoms 2.0 - Where is telecoms heading?

In this webcast, our panel of experts will review where we are with next generation telecoms in the UK, working through the concept of 'Telecoms 2.0': - Realising the potential of Next Generation Networks - why it isn't just about the technology? - What attributes should firms be looking for in their telco partner? - Is the relationship between telco provider and customer changing? - What things need to happen to make next generation services a reality? - You say you want the supplier to change. Do you want to change too? - What is Telecoms 2.0?

Publisher:
ZDNet UK

Telecom 2.0: Mind over matter

ntl:Telewest Business believes that the role of the telco is evolving. Gone are the days when it was enough to simply focus on circuits and minutes, customers now need a far higher degree of interaction and look for suppliers who will talk business solutions with them.

Publisher:
ntl:Telewest Business

IBM Information Server Change Data Capture

In today's fast-paced world, access to real-time data has never been more important. To be successful, organizations need to be able to report and analyze corporate data quickly and easily, regardless of what applications created the data, what platform they're running on, or what database they're stored in.

Publisher:
IBM

An examination of server consolidation: the trends that can drive efficiencies and help businesses gain a competitive edge

This white paper provides a starting point for organizations contemplating server consolidation. It includes an overview of server consolidation concepts and techniques and provides guidance on methodologies. It also looks at the potential cost savings associated with server consolidation and offers information on how organizations can sustain the advantage they have gained by consolidating their servers.

Publisher:
IBM

Also on silicon.com

Site Navigation:

Modems White Papers

MIMO OFDM Receivers for Systems With IQ Imbalances

Quick Sitemap Links:

About Us

Search

Blogs

Verticals

Advertising Features

CNET Networks in Europe

CNET Networks in the United States

CNET Networks in Asia Pacific