Distributed Space-Time Block Coded OFDM for Relay-Assisted Transmission
Bibliographic record
Abstract
In this paper, we investigate orthogonal frequency division multiplexing (OFDM) technique for distributed space-time block coding (D-STBC) in a relay-assisted transmission scenario over frequency-selective fading channels. We consider the special case of a single-relay where the source-to-relay (S - R), relay-to-destination (R - D) and source-to-destination (S - D) links experience possibly different channel delay spreads. Our analysis demonstrates that uncoded distributed OFDM-STBC (D-OFDM-STBC) scheme achieves a maximum diversity order of two for the considered single-relay scenario since it is able to exploit only the spatial diversity, but not the available rich multipath diversity. We further consider a combination of D-OFDM-STBC and Trellis Coded Modulation (TCM) with frequency-interleaving. Under the assumption of perfect power control for the relay terminal and high signal-to-noise ratio for the underlying links, our performance analysis demonstrates that D-OFDM-STBC scheme with judiciously designed outer TCM codes, i.e. sufficiently large effective code length (ECL), is able to achieve a maximum diversity order of min(L1, L3) + L2 + 2 where L1, L2, and L3 are the channel memory lengths for S - R, S - D and R - D links, respectively. This illustrates that the smaller of the multipath diversity orders experienced in S - R and R - D links becomes the performance bottleneck for the relaying path. An extensive Monte Carlo simulation study is presented to corroborate the analytical results and to provide further insights into the performance.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.004 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".