公开(公告)号：US06154499A

公开(公告)日：2000-11-28

申请号：US734086

申请日：1996-10-21

申请人： Bangalor Ramachandra Rao Udaya Bhaskar ,  Farhad Hemmati

发明人： Bangalor Ramachandra Rao Udaya Bhaskar ,  Farhad Hemmati

IPC分类号： H04L1/00 ,  H04L27/00

CPC分类号： H04L1/0036 ,  H04L1/0009 ,  H04L1/0014 ,  H04L1/0032 ,  H04L1/007

摘要： A communication network, comprising data transmission and data receiving systems and operations, for carrying reliable voice communications, particularly for mobile communications applications involving land-mobile, aeronautical and maritime systems. Because the quality of the links in such systems may vary, the present invention combines a nested codec with a channel coder at the transmission side of the link and a decoder at the reception side. The nested codec will transmit at a constant rate, which is the highest bit rate possible in the system, but according to channel conditions, will reconstruct voice at different bit rates. Thus, for example, transmission will always occur at a rate of 3600, but the reconstruction of the transmitted signal will be at 2400 or 1200 bps, depending on the quality of the signal. Notably, the lower two rates are subsets of the higher rate, thus defining their "nested" characteristic. Moreover, the rate reductions from the constant maximum rate occur automatically at the receiver, without transmitter control, based on the detected degraded conditions at the receiver. Because the rates are nested, they are a known multiple of the lowest rate.

摘要翻译： 一种包括数据传输和数据接收系统和操作的通信网络，用于承载可靠的语音通信，特别是涉及陆地移动，航空和海事系统的移动通信应用。 由于这种系统中的链路的质量可能变化，本发明将嵌套编解码器与链路的发送侧的信道编码器和接收侧的解码器相结合。 嵌套编解码器将以恒定速率传输，这是系统中可能的最高比特率，但根据信道条件，将以不同比特率重建语音。 因此，例如，传输总是以3600的速率发生，但是根据信号的质量，发射信号的重建将在2400或1200bps。 值得注意的是，较低的两个速率是较高速率的子集，因此定义了它们的“嵌套”特征。 此外，根据接收机的检测到的恶化条件，从接收机自动发生恒定最大速率的速率降低，无需发射机控制。 因为利率是嵌套的，它们是最低利率的已知倍数。