On the Code and Interleaver Design of Broadband OFDM Systems

A high-speed low-complexity hardware interleaver/deinterleaver is presented. It supports all 77 802.11n high-throughput (HT) modulation and coding schemes (MCSs) with short and long guard intervals and the 8 non-HT MCSs defined in 802.11a/g. The paper proposes a design methodology that distributes the three permutations of an interleaver to both write address and read address. The methodology not only reduces the critical path delay but also facilitates the address generation. In addition, the complex mathematical formulas are replaced with optimized hardware structures in which hardware intensive dividers and multipliers are avoided. Using 0.13 um CMOS technology, the cell area of the proposed interleaver/deinterleaver is 0.07 mm 2 , and the synthesized maximal working frequency is 400 MHz. Comparison results show that it outperforms the three other similar works with respect to hardware complexity and max frequency while maintaining high flexibility.

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“…We analyze (9) using the similar manner as described for (8). The behavior of (1)-(2) for 64QAM is obtained as shown in Figure 4.…”

Section: Optimized Hardware Structuresmentioning

confidence: 99%

“…It plays a key role in exploiting spatial diversity and frequency diversity [5]. Interleaving algorithms for high-throughput (HT) wireless communication system to reduce the decoding errors have been proposed in [6][7][8][9]. Hardware architectures for 802.11a/g interleaver have been reported in several literatures [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Low‐Complexity Hardware Interleaver/Deinterleaver for IEEE 802.11a/g/n WLAN

Zhang

Zhou

et al. 2012

VLSI Design

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“…After a block interleaver with interleaving depth d, most of the entries in V will differ by integer multiples of d. Using this fact, it has been shown analytically that a block interleaver with an interleaving depth N/(N t L) is nearly optimal for trellis codes over channels with i.i.d. path gains (i.e., D = 1/LI) [26]. For non-uniform power delay profiles, an optimal interleaver depth can be readily found by a computer search.…”

Section: Code and Interleaver Designmentioning

confidence: 99%

“…Proof: The proof for (28) can be found from [26]. Proposition 2: For the proposed multiplexing scheme, let a codeword matrix of size K × N collect symbols according to their associated layers and frequency locations (i.e., whose (i, j)th entry is the symbol of layer i to be transmitted at tone j).…”

Section: B Code and Receiver Designmentioning

confidence: 99%

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A new approach to diversity and multiplexing gains for wideband MIMO channels

Alkhawaldeh

Shayan

2007

IEEE Trans. Wireless Commun.

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In this paper, a new approach to improving reliability and bandwidth efficiency in communications over frequencyselective channels using multiple antennas is proposed. In the heart of the new approach is a novel space-time orthogonal frequency division multiplexing (OFDM) scheme. The proposed space-time OFDM modulator translates a multiple-input multiple-output (MIMO) channel into a single-input multipleoutput (SIMO) channel without the loss of system freedom (the available diversity gain). This translation simplifies code design as compared to that in the conventional MIMO OFDM approach. Instead of more complicated space-time codes, codes that are designed for single-input fading channels can be used with the proposed space-time modulation. For bandwidth-efficient applications, a channel multiplexing scheme is developed to work with the space-time modulator. Unlike the conventional spatial multiplexing schemes, an arbitrary number of data streams can be created and each layer occupies all the transmit antennas all the time. As a result, all the available degrees of freedom are preserved for each layer and a full range of optimal tradeoffs between data rate and reliability is possible. Several examples are given to demonstrate the advantages of the proposed approach over the conventional MIMO OFDM approach.

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Bibliography

2010

MIMO‐OFDM for LTE, Wi‐Fi and WiMAX

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On the Code and Interleaver Design of Broadband OFDM Systems

Cited by 16 publications

References 8 publications

Low‐Complexity Hardware Interleaver/Deinterleaver for IEEE 802.11a/g/n WLAN

Low‐Complexity Hardware Interleaver/Deinterleaver for IEEE 802.11a/g/n WLAN

A new approach to diversity and multiplexing gains for wideband MIMO channels

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