CHANNEL CODING WITH MULTILEVEL PHASE SIGNALS
CHANNEL CODING WITH MULTILEVEL PHASE SIGNALS
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DOI：
10.1109/tit.1982.1056454
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发表时间：
1982-01-01
影响因子：
2.5
通讯作者：
UNGERBOECK, G
中科院分区：
文献类型：
--
作者：
UNGERBOECK, G
本发明描述了一种编码技术，其在不牺牲数据速率或需要更多带宽的情况下改善同步数据链路的差错性能。这是通过以增加自由欧几里德距离的方式用扩展的多级/相位信号集进行信道编码来实现的。软最大似然（ML）译码采用维特比算法。在讨论信道容量后，给出了用于8相移键控（PSK）和16正交幅移键控（QASK）调制的简单手工设计的格形码。这些简单的代码实现了3-4 dB量级的编码增益。然后，它表明，代码可以被解释为二进制卷积码与映射的编码位到信道信号，我们称之为“映射集分割。基于一种新的二进制码序列之间的距离测度，它有效地降低了相应信道信号序列之间的欧几里得距离，开发了一种搜索更强大的码的过程。编码增益高达6 dB的代码获得了各种多电平/相位调制方案。仿真结果和载波相位跟踪的例子进行了讨论。
A coding technique is described which improves error performance of synchronous data links without sacrificing data rate or requiring more bandwidth. This is achieved by channel coding with expanded sets of multilevel/phase signals in a manner which increases free Euclidean distance. Soft maximum--likelihood (ML) decoding using the Viterbi algorithm is assumed. Following a discussion of channel capacity, simple hand-designed trellis codes are presented for 8 phase-shift keying (PSK) and 16 quadrature amplitude-shift keying (QASK) modulation. These simple codes achieve coding gains in the order of 3-4 dB. It is then shown that the codes can be interpreted as binary convolutional codes with a mapping of coded bits into channel signals, which we call "mapping by set partitioning." Based on a new distance measure between binary code sequences which efficiently lower-bounds the Euclidean distance between the corresponding channel signal sequences, a search procedure for more powerful codes is developed. Codes with coding gains up to 6 dB are obtained for a variety of multilevel/phase modulation schemes. Simulation results are presented and an example of carrier-phase tracking is discussed.