Project

General

Profile

OsmoTRX » History » Version 13

ttsou, 02/19/2016 10:47 PM

1 1 ttsou
= OsmoTRX =
2 1 ttsou
3 1 ttsou
OsmoTRX is a software-defined radio transceiver that implements the Layer 1 physical layer of a BTS comprising the following 3GPP specifications:
4 1 ttsou
 * TS 05.01 "Physical layer on the radio path"
5 1 ttsou
 * TS 05.02 "Multiplexing and Multiple Access on the Radio Path"
6 1 ttsou
 * TS 05.04 "Modulation"
7 1 ttsou
 * TS 05.10 "Radio subsystem synchronization"
8 1 ttsou
9 6 ttsou
OsmoTRX is based on the OpenBTS transceiver, but setup to operate independently with the purpose of using with non-OpenBTS software and projects. Currently there are numerous features contained in OsmoTRX that extend the functionality of the OpenBTS transceiver. These features include enhanced support for embedded platforms - notably ARM - and dual channel diversity support for the Fairwaves UmTRX. Most of these features will eventually be merged into mainline OpenBTS, but primary development will occur on OsmoTRX.
10 6 ttsou
11 6 ttsou
== Features ==
12 6 ttsou
13 9 ttsou
Intel SSE Support
14 6 ttsou
* SSE3
15 6 ttsou
* SSE4.1
16 6 ttsou
17 6 ttsou
On Intel processors, OsmoTRX makes heavy use of the Streaming SIMD Extensions (SSE) instruction set. Accelerated operations include pulse shape filtering, resampling, sequence correlation, and many other signal processing operations. SSE3 is the minimum requirement for accelerated use. SSE3 is present in the majority of Intel processors since later versions of the Pentium 4 architecture and is also present on low power Atom processors.
18 6 ttsou
19 6 ttsou
ARM NEON Support
20 6 ttsou
* NEON
21 6 ttsou
* NEON-VFPv4
22 6 ttsou
23 1 ttsou
OsmoTRX runs on a variety of ARM processors with and without NEON coprocessors. Like SSE on Intel processors, NEON provides acceleration with SIMD vectorized instructions. Tested popular architectures include ARM11 (Raspberry Pi), Cortex-A8 (BeagleBoard), and Cortex-A15 (ArndaleBoard). These platforms include no NEON coprocessor, standard NEON, and NEON-VFPv4 respectively. The latter NEON variation, VFPv4, provides additional fused-multiply-accumulate (FMA) instructions useful for many DSP operations. NEON optimization must be used enabled at built time.
24 9 ttsou
25 6 ttsou
Dual Channel (UmTRX only)
26 6 ttsou
27 7 ttsou
Two dual channel modes are available: standard dual channel mode and diversity. In standard dual channel mode, each RF
28 7 ttsou
path of the dual channel device - currently only UmTRX - supports a different ARFCN. Each path operates independently a
29 7 ttsou
nd operates similarly to two separate devices. GSM channel capacity in this mode is doubled.
30 7 ttsou
31 6 ttsou
Dual Channel Diversity (UmTRX only)
32 7 ttsou
33 8 ttsou
Diversity mode is similar to the standard dual channel mode except each antenna supports both ARFCN channels. In this case, the receiver sample bandwidth is widened to handle both ARFCN's and subsequently converted and demultiplexed into separate sample streams. Each GSM receive path is fed dual signals, where antenna selection diversity is performed by taking the stronger signal on a burst-by-burst basis. The limitations are increased CPU utilization and that ARFCN spacing is restricted (currently at 400 kHz) by the receiver sampling bandwidth. Setting the ARFCN spacing beyond the sampling limit will disable the diversity path.
34 1 ttsou
35 1 ttsou
Low Phase Error Modulator
36 8 ttsou
37 9 ttsou
The default GSM downlink signal is configured for low distortion using a linearized GMSK modulator. The implementation is based on a two pulse Laurent approximation of continuous phase modulated (CPM) signals. On capable devices, the signal measures with very low phase error and passes industry specturm mask specifications.
38 1 ttsou
39 1 ttsou
== Hardware support ==
40 1 ttsou
41 9 ttsou
Fairwaves
42 9 ttsou
||UmTRX||
43 9 ttsou
44 1 ttsou
Ettus Research
45 1 ttsou
||USRP1||
46 1 ttsou
||USRP2||
47 1 ttsou
||B100||
48 1 ttsou
||B110||
49 1 ttsou
||B200||
50 1 ttsou
||B210||
51 1 ttsou
||N200||
52 1 ttsou
||N210||
53 1 ttsou
||E100||
54 1 ttsou
||E110||
55 1 ttsou
56 1 ttsou
== Embedded Platform Support ==
57 1 ttsou
58 1 ttsou
OsmoTRX has been tested on the following embedded platforms.
59 1 ttsou
60 9 ttsou
||Platform||Processor||SIMD/FPU||
61 1 ttsou
||BeagleBoard-xM||ARM Cortex-A8||NEON||
62 1 ttsou
||ArndaleBoard||ARM Cortex-A15||NEON-VFPv4||
63 2 ttsou
||RaspberryPi||ARMv6k||VFP||
64 2 ttsou
||Shuttle PC||Intel Atom D2550||SSE3||
65 2 ttsou
||Ettus E100||ARM Cortex-A8||NEON||
66 1 ttsou
67 10 ttsou
== Benchmarks ==
68 10 ttsou
69 13 ttsou
Selected benchmark results are provided below. All tests run on a single core only.
70 1 ttsou
71 13 ttsou
Intel Haswell (i7 4770K 3.5 GHz)
72 11 ttsou
73 13 ttsou
{{{
74 13 ttsou
--- Floating point to integer conversions
75 11 ttsou
-- Testing 40000 iterations of 3120 values
76 11 ttsou
- Measuring conversion time
77 13 ttsou
- Elapsed time base...                  0.065508 secs
78 13 ttsou
- Validating SIMD conversion results... PASS
79 12 ttsou
- Measuring conversion time
80 13 ttsou
- Elapsed time SIMD ...                 0.011424 secs
81 13 ttsou
- Speedup...                            5.734244
82 11 ttsou
}}}
83 11 ttsou
84 13 ttsou
{{{
85 11 ttsou
[+] Testing: GSM TCH/AFS 7.95 (recursive, flushed, punctured)
86 10 ttsou
[.] Input length  : ret = 165  exp = 165 -> OK
87 10 ttsou
[.] Output length : ret = 448  exp = 448 -> OK
88 1 ttsou
[.] Pre computed vector checks:
89 1 ttsou
[..] Encoding: OK
90 1 ttsou
[..] Decoding base: 
91 1 ttsou
[..] Decoding SIMD: 
92 1 ttsou
[..] Code N 3
93 1 ttsou
[..] Code K 7
94 1 ttsou
OK
95 1 ttsou
[.] Random vector checks:
96 1 ttsou
[.] Testing baseline:
97 1 ttsou
[..] Encoding / Decoding 10000 cycles:
98 1 ttsou
[.] Elapsed time........................ 1.435066 secs
99 1 ttsou
[.] Rate................................ 3.121808 Mbps
100 1 ttsou
[.] Testing SIMD:
101 1 ttsou
[..] Encoding / Decoding 10000 cycles:
102 1 ttsou
[.] Elapsed time........................ 0.073524 secs
103 1 ttsou
[.] Rate................................ 60.932485 Mbps
104 1 ttsou
[.] Speedup............................. 19.518334
105 13 ttsou
}}}
106 13 ttsou
107 13 ttsou
BeagleBoard-xM (ARM Cortex-A8 800 MHz)
108 13 ttsou
{{{
109 13 ttsou
--- Floating point to integer conversions
110 13 ttsou
-- Testing 40000 iterations of 3120 values
111 13 ttsou
- Measuring conversion time
112 13 ttsou
- Elapsed time base...                  6.292542 secs
113 13 ttsou
- Validating SIMD conversion results... PASS
114 13 ttsou
- Measuring conversion time
115 13 ttsou
- Elapsed time SIMD ...                 0.839081 secs
116 13 ttsou
- Quotient...                           7.499326
117 13 ttsou
}}}
118 13 ttsou
119 13 ttsou
{{{
120 13 ttsou
[+] Testing: GSM TCH/AFS 7.95 (recursive, flushed, punctured)
121 13 ttsou
[.] Input length  : ret = 165  exp = 165 -> OK
122 13 ttsou
[.] Output length : ret = 448  exp = 448 -> OK
123 13 ttsou
[.] Pre computed vector checks:
124 13 ttsou
[..] Encoding: OK
125 13 ttsou
[..] Decoding base: 
126 13 ttsou
[..] Decoding SIMD: 
127 13 ttsou
[..] Code N 3
128 13 ttsou
[..] Code K 7
129 13 ttsou
OK
130 13 ttsou
[.] Random vector checks:
131 13 ttsou
[.] Testing baseline:
132 13 ttsou
[..] Encoding / Decoding 10000 cycles:
133 13 ttsou
[.] Elapsed time........................ 21.963257 secs
134 13 ttsou
[.] Rate................................ 0.203977 Mbps
135 13 ttsou
[.] Testing SIMD:
136 13 ttsou
[..] Encoding / Decoding 10000 cycles:
137 13 ttsou
[.] Elapsed time........................ 3.083282 secs
138 13 ttsou
[.] Rate................................ 1.452997 Mbps
139 13 ttsou
[.] Speedup............................. 7.123337
140 10 ttsou
}}}
141 10 ttsou
142 1 ttsou
== Status ==
143 1 ttsou
144 1 ttsou
== GPRS support ==
145 1 ttsou
146 1 ttsou
== Source code ==
147 1 ttsou
148 1 ttsou
The source code is available from git.osmocom.org (module osmo-trx).
149 1 ttsou
150 1 ttsou
Public read-only access is available via
151 1 ttsou
 git clone git://git.osmocom.org/osmo-trx
152 1 ttsou
You can browse it via cgit: http://cgit.osmocom.org/cgit/osmo-trx/
153 1 ttsou
154 3 ttsou
== Configuration and Build ==
155 3 ttsou
156 3 ttsou
The only package dependency is the Universal Hardware Driver (UHD).
157 3 ttsou
158 3 ttsou
{{{
159 3 ttsou
$ ./configure
160 3 ttsou
$ make
161 3 ttsou
$ sudo make install
162 3 ttsou
}}}
163 3 ttsou
164 3 ttsou
== Running ==
165 3 ttsou
166 3 ttsou
{{{
167 3 ttsou
$ osmo-trx -h
168 3 ttsou
linux; GNU C++ version 4.8.1 20130603 (Red Hat 4.8.1-1); Boost_105300; UHD_003.005.004-140-gfb32ed16
169 3 ttsou
170 3 ttsou
Options:
171 3 ttsou
  -h    This text
172 3 ttsou
  -a    UHD device args
173 3 ttsou
  -l    Logging level (EMERG, ALERT, CRT, ERR, WARNING, NOTICE, INFO, DEBUG)
174 3 ttsou
  -i    IP address of GSM core
175 3 ttsou
  -p    Base port number
176 3 ttsou
  -d    Enable dual channel diversity receiver
177 3 ttsou
  -x    Enable external 10 MHz reference
178 3 ttsou
  -s    Samples-per-symbol (1 or 4)
179 3 ttsou
  -c    Number of ARFCN channels (default=1)
180 3 ttsou
}}}
181 3 ttsou
182 3 ttsou
{{{
183 5 ttsou
$ osmo-trx -a "addr=192.168.10.2"
184 3 ttsou
linux; GNU C++ version 4.8.1 20130603 (Red Hat 4.8.1-1); Boost_105300; UHD_003.004.000-b14cde5
185 3 ttsou
186 3 ttsou
Config Settings
187 4 ttsou
   Log Level............... INFO
188 3 ttsou
   Device args............. addr=192.168.10.2
189 3 ttsou
   TRX Base Port........... 5700
190 3 ttsou
   TRX Address............. 127.0.0.1
191 3 ttsou
   Channels................ 1
192 3 ttsou
   Samples-per-Symbol...... 4
193 3 ttsou
   External Reference...... Disabled
194 3 ttsou
   Diversity............... Disabled
195 3 ttsou
196 3 ttsou
-- Opening a UmTRX device...
197 3 ttsou
-- Current recv frame size: 1472 bytes
198 3 ttsou
-- Current send frame size: 1472 bytes
199 3 ttsou
-- Setting UmTRX 4 SPS
200 3 ttsou
-- Transceiver active with 1 channel(s)
201 3 ttsou
}}}
202 3 ttsou
203 1 ttsou
== Authors ==
204 1 ttsou
205 1 ttsou
OsmoTRX is currently developed and maintained by Thomas Tsou. The original code is derived from the OpenBTS project, which was developed by David Burgess and Harvind Samra at Range Networks.
Add picture from clipboard (Maximum size: 48.8 MB)