CMOS digital adaptive decision feedback equalizer chip for multilevel QAM digital radio modems

Among existing works of high-speed pipelined adaptive decision feedback equalizers (ADFE), the pipelined ADFE using relaxed look-ahead technique results in a substantial hardware saving than the parallel processing or other look-ahead approaches. For example, Shanbhag and Partiz derived three pipeline ADFE structures (PIPEADFE1, 2, 3), where PIPEADFE2 yields very good performance in terms of convergence rate and hardware cost. Nevertheless, the PIPEADFE2 employs Approximation Methods in deriving the Preprocessing Unit (PP). In this paper, a new pipelining ADFE architecture is developed. We derive a new updating ADFE scheme based on the Principle of Orthogonality. By employing the postcursor processing filter (PCF) to cancel the most significant postcursor Intersymbol interference (ISI) terms, the proposed PCFADFE architecture can significantly improve the convergence rate of the ADFE. Compared with PIPEADFE2, it has better convergence rate while at similar hardware cost. Hence, it provides an alternative approach for the design of high-speed pipelining ADFE with arbitrary speedup factor.

show abstract

“…1 and 2, respectively. Basically, the PIPEADFE1 is an extension of the ADFE algorithm proposed in [7]. PI-PEADFE2 is a variant of PIPEADFE1.…”

Section: Review Of Pipelined Adfe Architecturesmentioning

confidence: 99%

Fast Convergent Pipelined Adaptive DFE Architecture Using Post-Cursor Processing Filter Technique

Yang

Lai

2004

IEEE Trans. Circuits Syst. II

View full text Add to dashboard Cite

show abstract

“…The adaptive equalizer consists of a configurable time-domain equalizer preceded by an adaptive frequency-domain equalizer. The position of the reference taps of the adaptive time-domain equalizer is programmable, e.g., to provide optimal cascadability with an identical chip or with a decision-feedback equalizer [4]. Elastic storage for the input samples is included for compensating the sample-phase differences occurring in synchronous co-channel transmission mode (XPIC).…”

Section: Introductionmentioning

confidence: 99%

Architecture and circuit design of a 6-GOPS signal processor for QAM demodulator applications

Man

Schulz²,

Schmidmaier³

et al. 1995

IEEE J. Solid-State Circuits

Self Cite

View full text Add to dashboard Cite

A QAM processor for applications in QAM demodulators with baud rates of up to 60 Mbaud and modulation schemes of up to 1024 QAM has been implemented on a single chip. The chip performs 11-tap complex-valued adaptive timedomain equalization and the complete digital base-band signal processing of high-capacity QAM demodulators. This includes frequency-domain slope equalization and the digital parts of the timing and carrier recovery as well as the gain and offset control for the A-to-D converters. The equalizer can be operated in baud spaced and half-baud spaced mode and can also be applied for cross-polarization interference cancellation. The computational power of the QAM processor exceeds 6 giga-multiply-accumulate operations per second. Fabricated in an 1.0-pm CMOS technology on a silicon area of 185 mm2 this 800 K-transistor chip demonstrates the potential of such low-cost technologies. The maximum clock frequency under worst-case conditions is 60 MHz. The corresponding power dissipation is 4.2 W.

show abstract

Carry-save architectures for high-speed digital signal processing

Noll

1991

J VLSI Sign Process Syst Sign Image Video Technol

110

View full text Add to dashboard Cite

CMOS digital adaptive decision feedback equalizer chip for multilevel QAM digital radio modems

Cited by 14 publications

References 4 publications

Fast Convergent Pipelined Adaptive DFE Architecture Using Post-Cursor Processing Filter Technique

Fast Convergent Pipelined Adaptive DFE Architecture Using Post-Cursor Processing Filter Technique

Architecture and circuit design of a 6-GOPS signal processor for QAM demodulator applications

Carry-save architectures for high-speed digital signal processing

Contact Info

Product

Resources

About