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1. 发明申请

WO1994009582A1 BIDIRECTIONAL DEMODULATION METHOD AND APPARATUS 审中-公开
标题翻译：双向解调方法和装置
公开(公告)号：WO1994009582A1
公开(公告)日：1994-04-28
申请号：PCT/US1993010087
申请日：1993-10-21
申请人： ERICSSON GE MOBILE COMMUNICATIONS INC.
发明人： ERICSSON GE MOBILE COMMUNICATIONS INC. , DENT, Paul, W. , CHENNAKESHU, Sandeep
IPC分类号： H04L25/03
CPC分类号： H04L27/2337 , H04B7/0857 , H04L25/03178 , H04L2025/0356
摘要： A method and apparatus (100) for demodulating data symbols transmitted through a fading communication channel (40). A plurality of first predetermined data symbols (11), a plurality of unknown data symbols (12, 14), and a plurality of second predetermined data symbols (13) are sequentially received. The received pluralities of data symbols are stored, and first and second sets of reference signals from the stored pluralities of first and second predetermined data symbols, respectively, are determined. The stored unknown data symbols based on the first set of reference signals are forward-demodulated, beginning with unknown symbols received nearer the first predetermined data symbols. The stored unknown data symbols based on the second set of reference signals are backward-demodulated, beginning with the unknown data symbols received nearer the second determined data symbols. Quality values indicative of demodulation qualities of the forward- and backward-demodulated data symbols are determined. The quality values are compared, and either the forward- or backward-demodulated data symbols are selected based on the comparison of quality values.
摘要翻译：一种用于解调通过衰落通信信道（40）发送的数据符号的方法和装置（100）。顺序地接收多个第一预定数据符号（11），多个未知数据符号（12,14）和多个第二预定数据符号（13）。存储所接收的多个数据符号，并且分别确定来自存储的多个第一和第二预定数据符号的第一和第二组参考信号。基于第一组参考信号的存储的未知数据符号被正向解调，从接近第一预定数据符号的未知符号开始。基于第二组参考信号的存储的未知数据符号被反向解调，从接近第二确定数据符号的未知数据符号开始。确定表示前向和后向解调数据符号的解调质量的质量值。比较质量值，并且基于质量值的比较来选择前向或后向解调的数据符号。

2. 发明申请

WO1993026105A1 IMPROVED TRELLIS CODING TECHNIQUE TO INCREASE ADJACENT CHANNEL INTERFERENCE PROTECTION RATIO IN LAND MOBILE RADIO SYSTEMS UNDER PEAK POWER CONSTRAINTS 审中-公开
标题翻译：改进的TRELLIS编码技术，以增加土地移动无线电系统在峰值功率约束下的相邻通道干扰保护比例
公开(公告)号：WO1993026105A1
公开(公告)日：1993-12-23
申请号：PCT/US1993005524
申请日：1993-06-10
申请人： ERICSSON GE MOBILE COMMUNICATIONS INC.
发明人： ERICSSON GE MOBILE COMMUNICATIONS INC. , CHENNAKESHU, Sandeep , RAMESH, Rajaram , HASSAN, Amer, A. , ANDERSON, John, B.
IPC分类号： H04L05/12
CPC分类号： H03M13/256 , H03M13/00 , H03M13/25 , H04L27/186
摘要： An optimum communication system employs an encoder (94) coupled to a mapper (96) and two parallel branches (I and Q), each branch having a transmit filter (98a and 98b), a digital-to-analog converter (99a and 99b), a low pass filter (100a and 100b) and a modulator coupled in series (102a and 102b). Both modulators are coupled to a summer (97) which provides an rf signal to a transmit antenna (103). A second antenna (104) is coupled to a first down converter (106), an IF filter (107), a second down converter (109), an analog-to-digital converter (108) and a decoder (111). The encoder is optimized by choosing a desired minimum Euclidean distance between symbols multiplied by the average to peak transmit power ratio (MPDR), an encoder alphabet and a number of constellation points. All possible encoder states and all possible input symbols are permutated to result in a plurality of encoder sets. The minimum distance between coded symbols and a Pib/Pab power ratio for each code set is determined. The encoder is adapted to output an encoder set U having a largest Pib/Pab power ratio having a large adjacent channel interference protection ratio. In an alternative embodiment, a minimum Pib/Pab power ratio (MPR) is chosen. The encoder is adapted to output an encoder set U having the largest minimum distance between coded symbols multiplied by the average to peak transmitted power ratio, that also has a Pib/Pab ratio that exceeds MPR.

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