Power Loading Using Order Mapping in OFDM Systems With Limited Feedback

Choi, Eun Ho; Choi, Wan; Andrews, Jeffrey G.; Womack, Baxter F.

doi:10.1109/lsp.2008.925755

Cited by 20 publications

(16 citation statements)

References 10 publications

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“…Later work on quantized feedback in OFDM to activate or deactivate subchannels was the focus of [306], [307]. More general schemes for jointly quantizing the per subcarrier power allocations have been discussed in [61], [201], [207], [262]. A sub-channel grouping approach was developed in [3], [4].…”

Section: Decoder Encoder Channel Side Informationmentioning

confidence: 99%

An overview of limited feedback in wireless communication systems

Love

Heath

Lau

et al. 2008

IEEE J. Select. Areas Commun.

1,353

918

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Abstract-It is now well known that employing channel adaptive signaling in wireless communication systems can yield large improvements in almost any performance metric. Unfortunately, many kinds of channel adaptive techniques have been deemed impractical in the past because of the problem of obtaining channel knowledge at the transmitter. The transmitter in many systems (such as those using frequency division duplexing) can not leverage techniques such as training to obtain channel state information. Over the last few years, research has repeatedly shown that allowing the receiver to send a small number of information bits about the channel conditions to the transmitter can allow near optimal channel adaptation. These practical systems, which are commonly referred to as limited or finite-rate feedback systems, supply benefits nearly identical to unrealizable perfect transmitter channel knowledge systems when they are judiciously designed. In this tutorial, we provide a broad look at the field of limited feedback wireless communications. We review work in systems using various combinations of single antenna, multiple antenna, narrowband, broadband, single-user, and multiuser technology. We also provide a synopsis of the role of limited feedback in the standardization of next generation wireless systems.

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Section: Decoder Encoder Channel Side Informationmentioning

confidence: 99%

An overview of limited feedback in wireless communication systems

Love

Heath

Lau

et al. 2008

IEEE J. Select. Areas Commun.

1,353

918

View full text Add to dashboard Cite

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“…This section shows the representative results of the proposed dynamic region based limited feedback scheme with comparison to the order mapping based limited feedback scheme [7] in terms of the amount of feedback information, the NMSE and the achievable spectral efficiency. In the simulations, the channel gains of all subcarriers are assumed to be generated by a correlated Rayleigh fading model [11].…”

Section: Numerical Resultsmentioning

confidence: 99%

“…[5] and [6] proposed limited feedback schemes based on comb-type channel information, where only the channel gains of the pilot symbols were fed back to the transmitter and then the channel gains of other subcarriers were estimated by interpolation. Furthermore, instead of feeding back all the subcarrier channel gains of comb-type pilots, [7] proposed a limited feedback scheme using order mapping and interpolation methods, where only the channel gain order of the comb-type pilots and the maximum and the minimum channel gains among all the comb-type pilots were fed back. It should be noted that the quantization errors in [7] can be minimized only when the channel gains of all subcarriers are uniformly distributed between the maximum and the minimum channel gains.…”

Section: Introductionmentioning

confidence: 99%

A Dynamic Region based Limited Feedback Scheme for Efficient Power Allocation in OFDM Systems

Wang

et al. 2013

IEEE Commun. Lett.

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This letter proposes a dynamic region based limited feedback scheme for efficient power allocation in orthogonal frequency division multiplexing (OFDM) systems. At the receiver, after obtaining the channel gains of all subcarriers by channel estimation, the maximum and the minimum channel gains can be determined easily. Using the maximum and the minimum channel gains, the proposed scheme divides the range of the channel gains into multiple regions adaptively. Each region is assigned with a unique index. Then each subcarrier will be allocated with the index of the region that its channel gain belongs to. The index information of all subcarriers can be denoted by a code from a predetermined codebook. Along with the maximum and the minimum channel gains, only the codes will be fed back. The feedback information will be used to estimate the channel gains of all subcarriers at the transmitter. The simulation results show that the proposed scheme can improve both the accuracy of feedback channel gain information and the spectral efficiency with less feedback information overhead.

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“…The author considered a minimum square error channel prediction scheme to overcome the detrimental effect of feedback delay and proposed resource allocation algorithms to maximize the downlink throughput. The works in [15][16][17] focused on the imperfect CSI resulting from channel estimation error and proposed power loading algorithms for the single user OFDM system. Resource allocation with quantized CSI was investigated in [3][4][5].…”

Section: Related Workmentioning

confidence: 99%

Resource allocation for maximizing outage throughput in OFDMA systems with finite-rate feedback

Bai

Chen

et al. 2011

J Wireless Com Network

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Previous works on orthogonal frequency division multiple access (OFDMA) systems with quantized channel state information (CSI) were mainly based on suboptimal quantization methods. In this paper, we consider the performance limit of OFDMA systems with quantized CSI over independent Rayleigh fading channels using the rate-distortion theory. First, we establish a lower bound on the capacity of the feedback channel and build the test channel that achieves this lower bound. Then, with the derived test channel, we characterize the system performance with the outage throughput and formulate the outage throughput maximization problem with quantized channel state information (CSI). To solve this problem in low complexity, we develop a suboptimal algorithm that performs resource allocation in two steps: subcarrier allocation and power allocation. Using this approach, we can numerically evaluate the outage throughput in terms of feedback rate. Numerical results show that this suboptimal algorithm can provide a near optimal performance (with a performance loss of less than 5%) and the outage throughput with a limited feedback rate can be close to that with perfect CSI.

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Power Loading Using Order Mapping in OFDM Systems With Limited Feedback

Cited by 20 publications

References 10 publications

An overview of limited feedback in wireless communication systems

An overview of limited feedback in wireless communication systems

A Dynamic Region based Limited Feedback Scheme for Efficient Power Allocation in OFDM Systems

Resource allocation for maximizing outage throughput in OFDMA systems with finite-rate feedback

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