Added tx bursts preprocessing block
diff --git a/grc/transmitter/preprocess_tx_burst.xml b/grc/transmitter/preprocess_tx_burst.xml
new file mode 100644
index 0000000..70b447e
--- /dev/null
+++ b/grc/transmitter/preprocess_tx_burst.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0"?>
+<block>
+ <name>Preprocess Tx burst</name>
+ <key>gsm_preprocess_tx_burst</key>
+ <import>import grgsm</import>
+ <make>grgsm.preprocess_tx_burst()</make>
+
+ <sink>
+ <name>bursts_in</name>
+ <type>message</type>
+ <optional>1</optional>
+ </sink>
+
+ <source>
+ <name>bursts_out</name>
+ <type>message</type>
+ <optional>1</optional>
+ </source>
+</block>