Orthogonal frequency-division multiplexing (OFDM) is known as an efficient technique
to combat frequency-selective channels. In this paper, we show that the combination of
bit-interleaved coded modulation (BICM) and OFDM achieves the full frequency diversity
offered by a frequency-selective channel in noncoherent situation, conditioned on the
minimum Hamming distance dfree of the convolutional code. This system has a simple
Viterbi decoder with the modified cost metric. We can also reduce complexity by cyclic
ML in large scale case. In the identifiability analysis, we show that under independently
and identically distributed (i.i.d.) Rayleigh fading channels the proposed schemes can
ensure a probability one identifiability condition using a very small number of pilots.
We then prove that in L-pilot-symbol scheme, it can achieve the algebraic diversity. We
verify our analytical results via simulations, including channels employed in the IEEE
802.11 standards. Our simulation results show that the proposed noncoherent receiver
can provide good bit error rate performance.

正交分頻多工 (Orthogonal frequency-division multiplexing, 簡稱
OFDM) 是多載波調變技術的一種是由於高速資料傳輸和有效對抗
通道為選擇性頻率衰減的優點下，已成為現今為無線通訊廣泛所採
用。它也是一種對抗頻率選擇通道 (frequency selective channel) 非常
有效率的技術，而位元交錯 (Bit-interleaved coded modulation, 簡稱
BICM) 在現代的無線通訊系統中，位元交錯調變碼被利用來克服瑞
雷（Rayleigh）衰減通道，兩者均是下一世代通訊系統所採用的重要
技術。在這篇論文中，我們展示出在非相干頻率選擇通道下，位元交
錯 (Bit-interleaved coded modulation, 簡稱 BICM) 和正交分頻多工
(OFDM) 的組合在已知摺積碼 (convolutional code) 的最小漢明
(Hamming) 距離情況下可以達到代數分集性 (algebraic diversity)。這
個系統有一個 Viterbi 解碼器，而且我們在每個階段的每一個節點必
須計算一個目標值，但我們也提出可以不必在每個階段的每個節點都
去計算這個目標值來減少計算複雜度，所使用的方法是週期性的最大
勢然偵測。我們提供了一個資料鑑別的方法，對於盲蔽唯一資料鑑別，
我們證明所提出的檢測機制在獨立瑞雷衰減通道 (Rayleigh fading
channels) 中只需使用非常少量的前導資料 (pilot data) 就能保
證資料鑑別的唯一性，接著我們證明在頻率選擇通道情況下它可以達
到代數分集性，我們藉由模擬結果來證實我們所做的分析，所使用的
通道是跟據 IEEE 802.11 的標準。最後，我們的模擬結果展示出我
們所提出的非相干位元交錯正交分頻多工接收機有非常好的位元錯
誤率效能。

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