[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Discuss-gnuradio] USRP Tx and Rx IF sample rates
From: |
Eric Blossom |
Subject: |
[Discuss-gnuradio] USRP Tx and Rx IF sample rates |
Date: |
Fri, 18 Feb 2005 18:03:23 -0800 |
User-agent: |
Mutt/1.5.6i |
On Fri, Feb 18, 2005 at 05:49:26PM -0500, Bob Vincent wrote:
> Could you enumerate some of those possible rates here?
> I think we at least would find it useful to change rates.
Below are tables of acceptable Tx and Rx IF sample rates.
A couple of notes are in order. Matt's going to be making a change to
the FPGA that adds a half-band filter to the Tx and Rx paths. This is
a good thing (better alias rejection, flatter passband), but adds an
additional factor of 2 constraint to the acceptable interpolation and
decimation rates. The tables below reflect settings that are
acceptable under both the current and future scenarios.
Second, remember that you have a limit based on your USB throughput
(current best case 32MB/sec). Each complex sample is 4 bytes. If you
are running full-duplex or running more than a single Tx or Rx channel
you'll need to take that into account.
If you want to see all the tables, run this:
#!/usr/bin/env python
def print_table (start, stop, multiple, freq):
for x in range(start,stop+multiple,multiple):
print "%3d\t%13.4f" % (x, freq/x)
print "Tx Rates (now)"
print_table (4,512,4,128e6)
print "Tx Rates (future)"
print_table (8,1024,8,128e6)
print "Rx Rates (now)"
print_table (1,256,1,64e6)
print "Rx Rates (future)"
print_table (2,512,2,64e6)
----------------------------------------------------------------
Acceptable Tx IF sample rates
Interp Samples/sec
==== ===============
16 8,000,000.0000
24 5,333,333.3333
32 4,000,000.0000
40 3,200,000.0000
48 2,666,666.6667
56 2,285,714.2857
64 2,000,000.0000
72 1,777,777.7778
80 1,600,000.0000
88 1,454,545.4545
96 1,333,333.3333
104 1,230,769.2308
112 1,142,857.1429
120 1,066,666.6667
128 1,000,000.0000
136 941,176.4706
144 888,888.8889
152 842,105.2632
160 800,000.0000
168 761,904.7619
176 727,272.7273
184 695,652.1739
192 666,666.6667
200 640,000.0000
208 615,384.6154
216 592,592.5926
224 571,428.5714
232 551,724.1379
240 533,333.3333
248 516,129.0323
256 500,000.0000
264 484,848.4848
272 470,588.2353
280 457,142.8571
288 444,444.4444
296 432,432.4324
304 421,052.6316
312 410,256.4103
320 400,000.0000
328 390,243.9024
336 380,952.3810
344 372,093.0233
352 363,636.3636
360 355,555.5556
368 347,826.0870
376 340,425.5319
384 333,333.3333
392 326,530.6122
400 320,000.0000
408 313,725.4902
416 307,692.3077
424 301,886.7925
432 296,296.2963
440 290,909.0909
448 285,714.2857
456 280,701.7544
464 275,862.0690
472 271,186.4407
480 266,666.6667
488 262,295.0820
496 258,064.5161
504 253,968.2540
512 250,000.0000
Acceptable Rx IF sample rates
Decim Samples/sec
==== =============
8 8,000,000.0000
10 6,400,000.0000
12 5,333,333.3333
14 4,571,428.5714
16 4,000,000.0000
18 3,555,555.5556
20 3,200,000.0000
22 2,909,090.9091
24 2,666,666.6667
26 2,461,538.4615
28 2,285,714.2857
30 2,133,333.3333
32 2,000,000.0000
34 1,882,352.9412
36 1,777,777.7778
38 1,684,210.5263
40 1,600,000.0000
42 1,523,809.5238
44 1,454,545.4545
46 1,391,304.3478
48 1,333,333.3333
50 1,280,000.0000
52 1,230,769.2308
54 1,185,185.1852
56 1,142,857.1429
58 1,103,448.2759
60 1,066,666.6667
62 1,032,258.0645
64 1,000,000.0000
66 969,696.9697
68 941,176.4706
70 914,285.7143
72 888,888.8889
74 864,864.8649
76 842,105.2632
78 820,512.8205
80 800,000.0000
82 780,487.8049
84 761,904.7619
86 744,186.0465
88 727,272.7273
90 711,111.1111
92 695,652.1739
94 680,851.0638
96 666,666.6667
98 653,061.2245
100 640,000.0000
102 627,450.9804
104 615,384.6154
106 603,773.5849
108 592,592.5926
110 581,818.1818
112 571,428.5714
114 561,403.5088
116 551,724.1379
118 542,372.8814
120 533,333.3333
122 524,590.1639
124 516,129.0323
126 507,936.5079
128 500,000.0000
130 492,307.6923
132 484,848.4848
134 477,611.9403
136 470,588.2353
138 463,768.1159
140 457,142.8571
142 450,704.2254
144 444,444.4444
146 438,356.1644
148 432,432.4324
150 426,666.6667
152 421,052.6316
154 415,584.4156
156 410,256.4103
158 405,063.2911
160 400,000.0000
162 395,061.7284
164 390,243.9024
166 385,542.1687
168 380,952.3810
170 376,470.5882
172 372,093.0233
174 367,816.0920
176 363,636.3636
178 359,550.5618
180 355,555.5556
182 351,648.3516
184 347,826.0870
186 344,086.0215
188 340,425.5319
190 336,842.1053
192 333,333.3333
194 329,896.9072
196 326,530.6122
198 323,232.3232
200 320,000.0000
202 316,831.6832
204 313,725.4902
206 310,679.6117
208 307,692.3077
210 304,761.9048
212 301,886.7925
214 299,065.4206
216 296,296.2963
218 293,577.9817
220 290,909.0909
222 288,288.2883
224 285,714.2857
226 283,185.8407
228 280,701.7544
230 278,260.8696
232 275,862.0690
234 273,504.2735
236 271,186.4407
238 268,907.5630
240 266,666.6667
242 264,462.8099
244 262,295.0820
246 260,162.6016
248 258,064.5161
250 256,000.0000
252 253,968.2540
254 251,968.5039
256 250,000.0000