Lines Matching +full:signal +full:- +full:to +full:- +full:noise
1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
4 <meta http-equiv="content-type" content="text/html;charset=iso-8859-1">
13 <!-- #BeginDate format:En2m -->17-Jul-2014 02:17<!-- #EndDate -->
20 Modem Port: <tt>/dev/chu<i>u</i></tt>; 300 baud, 8-bits, no parity<br>
21 Autotune Port: <tt>/dev/icom</tt>; 1200/9600 baud, 8-bits, no parity<br>
25 …from Canadian time/frequency station <a href="http://inms-ienm.nrc-cnrc.gc.ca/time_services/shortw…
28 shortwave receiver can be tuned manually to one of these frequencies or, in
31 …to use either an audio codec or soundcard, or a Bell 103-compatible, 300-b/s modem or modem chip, …
32 …to the broadcast time when tracking a station. However, variations up to 0.3 ms can be expected du…
33 …to the PPS signal from a GPS receiver, the mean offset with a 2.4-GHz P4 running FreeBSD…
34 … performs a number of error checks to protect against overdriven or underdriven input signal level…
35 …ctable audio codec port and signal monitoring capabilities. For a discussion of these common featu…
37 …-kHz μ-law companded codec samples using maximum-likelihood techniques which exploit the consid…
38 …-ienm.nrc-cnrc.gc.ca/time_services/chu_e.html">CHU website</a>. A timecode is assembled when all b…
39 <h4>Baseband Signal Processing</h4>
40 …-likelihood UART, burst assembler and majority decoder. The DSP modem demodulates Bell 103 modem a…
41 …-stage shift registers, one for each of eight phases of the 300-b/s bit clock. At each phase a new…
42 …-robin order as the phases of each bit arrive. At the end of each bit all eight phases are searche…
43 <p>The burst assembler processes characters either from the maximum-likelihood UART or directly fro…
44 …-character blocks, each block representing ten 4-bit BCD digits. The format B blocks sent in secon…
45 …-inverted relative to the first, so a perfect burst of five 8-bit characters has distance -40. In …
47 …-bit code combination that might be decoded at that position. In order to use the character timest…
48 …ocessed, the value at the row corresponding to the digit position in the timecode and column corre…
49 … is the distance for that position and the corresponding code is the maximum-likelihood digit. If …
50 …-digit timecode representing the maximum-likelihood candidate for the transmitted timecode in that…
51 …to the reference clock interface along with the backdated timestamps accumulated over the minute. …
53 …to automatically tune the radio in response to changing radio propagation conditions throughout th…
54 …to open the device <tt>/dev/icom</tt> and, if successful will tune the radio to 3.331 MHz. The 1-k…
55 …-minute cycle. During the first four minutes it tunes to the station with the highest metric. Duri…
57 …to track the program status is using the <tt>ntpq</tt> program and the <tt>clockvar</tt> command. …
60 …-11) and <tt>b</tt> the burst distance (0-40). Good bursts will have spans of a 800 or more and th…
61 …-V interface for ICOM radios is active, a debug level greater than 1 will produce a trace of the C…
63 When enabled by the <tt>filegen</tt> facility, every received timecode is written to the <tt>clocks…
78 agc audio gain (0-255)
83 …d are in fixed-length format. The <tt>agc</tt> and <tt>lset</tt> fields, as well as the following …
86 …<dd>The sync indicator is initially <tt>?</tt> before the clock is set, but turns to space when th…
88 …-bit hexadecimal code showing which alarms have been raised during the most recent minute. Each bi…
93 …<dd>Decoder alarm. A majority of repetitions for at least one digit of the timecode fails to agree…
99 …oder alarms are fatal; the data accumulated during the minute are not used to set the clock. The f…
103 …<dd>The leap second warning is normally space, but changes to <tt>L</tt> if a leap second is to oc…
107 …<dd>The DUT sign and magnitude shows the current UT1 offset relative to the displayed UTC time, in…
109 …is is the number of minutes since the time was last verified relative to the broadcast signal.</dd>
111 …<dd>The audio gain shows the current codec gain setting in the range 0 to 255. Ordinarily, the rec…
114 code, if the CI-V interface is active, or <tt>CHU</tt> if not. The radio
118 …uring the most recent minute bursts were received. The values range from 0 to 160, with the higher…
120 …uring the most recent minute bursts were received. The values range from 0 to 60, with the higher …
129 <dd>Specifies the driver stratum, in decimal from 0 to 15, with default 0.</dd>
131 …<dd>Specifies the driver reference identifier, an ASCII string from one to four characters, with d…
135 …port, where 0 is the mike port (default) and 1 is the line-in port. It does not seem useful to sel…
137 …<dd>When the audio driver is compiled, this flag enables audio monitoring of the input signal. For…