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about modem
lh
2000-01-27 04:04:00
各位:
如何最大限度提高Modem的传输速率??,我急需这方面的资料。
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about modem
各位: 如何最大限度提高Modem的传输速率??,我急需这方面的资料。
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lqjin
2000-01-27
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去3721网站下载一个Modem加速软件,能最大限度提高Modem的传输速率
还有各项参数的详细书说明.
pjmplatemeta_programming.zip_The Program_通讯编程
This program is
ab
out the CDMA
modem
This is a MATL
AB
simulat
Modem
CID 1.1
30天试用版, 包含
Modem
CID OCX, 帮助文件, VB6, VB5和Access 97的例子程序.
Modem
CID is an ActiveX control that can monitor incoming telephone calls and give details
ab
out the calling party before the call is answered.
Modem
CID gives information such as the calling parties telephone number and name. Indication is also given if the caller has withheld their number or is out of area etc.
Modem
CID has multiline cap
ab
ilities and is
ab
le to monitor multiple telephone lines with multiple
modem
s. 更多的信息请看: http://www.comcomponents.com/
modem
_cid.html
Ab
out云大数据
学习大数据组件
Digital Signal Processing A Computer Science Perspective
I know what you are asking yourself--‘there are a lot of books avail
ab
le
ab
out DSP, is this book the one for me?’ Well that depends on who you are. If 1. you are interested in doing research and development in one of the many state-of-the-art applications of DSP, such as speech compression, speech recognition, or
modem
design, 2. your main proficiency or science rather than is in computer science,
ab
stract mathematics,electronics or electrical engineering, 3. your math ematical background is relatively strong (flip back now to the appendix-you should be comfort
ab
le with
ab
out half of what you see there), then you are definitely in the target group of this book.
DQPSK调制解调
A
modem
method known as p/4 offset, differentially encoded quadrature phase shift keying (p/4-DQPSK) has been adopted for the United States and Japanese digital cellular time division multiple access (TDMA) systems and Personal Communications Systems (PCS). The rationale for such a choice is the high bit rate-bandwidth ratio and its applic
ab
ility to noncoherent detection. Most current systems are implemented with analog hardware. In the p/4-DQPSK
modem
described in this thesis, DSP solutions are employed to process not only the baseband signal but also the intermediate frequency (IF) signal. The DSP technologies used in this
modem
include (1) Digital Complex Sampling, (2) Polyphase Filters, (3) Canonic Signed Digit Multipliers for FIR Filter, (4) Non-Data- Aided Timing Parameter Estimation, (5) Multirate Signal Processing. With these DSP solutions, various problems in analog and baseband DSP approaches, such as dc offset voltages, dc voltage drifts, analog filter phase distortions, quadrature phase and gain imbalance, and amplifier and mixer nonlinearities, are eliminated and very precise and controll
ab
le performance can be achieved without sophisticated compensation techniques. Other advantages of the DSP solutions include the
ab
ility to easily program the hardware to accommodate different data rates, modulation formats and filter specifications. The DSP solution is also an efficient method to minimize power consumption, size and cost of the systems. The mathematical model, simulation results, hardware designs in Very High Speed Integrated Circuit Hardware Description Language (VHDL), and testing results are presented in this thesis. The DSP-based p/4-DQPSK
modem
is designed and implemented on two Altera FLEX10K70 chips. The chip size is 4,428 logical cells (approximately 82k gates). The maximum bit rate is 5Mbit/sec. For an additive white Gaussian noise channel, the results of a bit error rate (BER) measurement indicate that the BER performance of the
modem
degrades
ab
out 1.5 dB from theory when 17th-order square root raised cosine matched iv filters are used. The performance degradation due to a carrier frequency offset is also investigated in terms of the BER.
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