baseband-devel June 2012

baseband-devel@lists.osmocom.org

19 participants
32 discussions

by Chengcheng Gou

Hi： I am studying the tch code, and want to decode the Convolutional code of TCH using xcch.c; and how to set the parameters; 1. conv_xcch_next_output 2. conv_xcch_next_state 3. N = 2, 4. K = 5, static const uint8_t conv_xcch_next_output[][2] = { { 0, 3 }, { 1, 2 }, { 0, 3 }, { 1, 2 }, { 3, 0 }, { 2, 1 }, { 3, 0 }, { 2, 1 }, { 3, 0 }, { 2, 1 }, { 3, 0 }, { 2, 1 }, { 0, 3 }, { 1, 2 }, { 0, 3 }, { 1, 2 }, }; static const uint8_t conv_xcch_next_state[][2] = { { 0, 1 }, { 2, 3 }, { 4, 5 }, { 6, 7 }, { 8, 9 }, { 10, 11 }, { 12, 13 }, { 14, 15 }, { 0, 1 }, { 2, 3 }, { 4, 5 }, { 6, 7 }, { 8, 9 }, { 10, 11 }, { 12, 13 }, { 14, 15 }, }; const struct osmo_conv_code conv_xcch = { .N = 2, .K = 5, .len = 224, .next_output = conv_xcch_next_output, .next_state = conv_xcch_next_state, }; Thanks!

13 years, 2 months

Can bb switch from SACCH to TCH directly?

by Chengcheng Gou

hi, i am studying the TCH ,and can get the channel discription from SACCH, and My question is when I receive the ASS_CMD, I use l1ctl_tx_dm_est_req_h0 and jump to the new channel,but I can`t capture the TCH,why? Thanks!

13 years, 2 months

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baseband-devel June 2012